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12,300 | External Cardioversion of Atrial Fibrillation Causes an Early Improvement of Cardiac Performance: A Longitudinal Strain Analysis Study. | Atrial fibrillation (AF) is often associated with heart failure. Several studies have demonstrated that resumption of sinus rhythm (SR) improves cardiac output in the long-term. Aims of this study were to evaluate the acute variations of left ventricular (LV) performance, following successful external cardioversion (ECV) of persistent AF using longitudinal strain (LSt) analysis, and the influence of inflammation.</AbstractText>We enrolled 48 patients with AF (age: 73 ± 12 years, men: 83.3%). A standard transthoracic echocardiographic evaluation was performed before the procedure and 6 h later; this included the analysis of LV endocardial peak LSt, a measure of myocardial deformation. In the last 32 patients, plasma concentration of interleukin-6 (IL-6) was also determined.</AbstractText>Restoration of SR led to the decrease of heart rate (HR) (74 ± 21 vs 64 ± 10 bpm, P</i> < 0.001) and LV end-systolic volume (30 ± 16 vs 27 ± 17 mL/m2</sup>, P</i> = 0.001), and to the increase of LV end-diastolic volume (LVEDV) (56 ± 20 vs 60 ± 21 mL/m2</sup>, P</i> = 0.036) and ejection fraction (EF) (48 ± 10 vs 57 ± 11%, P</i> < 0.001). Peak LSt improved in 43 (89.6%) patients (-12.9 ± 3.3 vs -18.0 ± 4.7%, P</i> < 0.001). Multivariate analysis (R</i> = 0.729, P</i> < 0.001) showed that strain changes were directly correlated with basal HR and the appearance of atrial mechanical activity and inversely correlated with corrected thyroid dysfunction, LVEDV and the presence of a permanent pacemaker. Higher levels of IL-6 negatively affected LV performance improvement.</AbstractText>Effective ECV of AF determines a significant and fast improvement of LV performance, which is readily captured by LSt analysis. Inflammatory status may impact the response to SR restoration.</AbstractText> |
12,301 | Alternans and Spiral Breakup in an Excitable Reaction-Diffusion System: A Simulation Study. | The determination of the mechanisms of spiral breakup in excitable media is still an open problem for researchers. In the context of cardiac electrophysiological activities, spiral breakup exhibits complex spatiotemporal pattern known as ventricular fibrillation. The latter is the major cause of sudden cardiac deaths all over the world. In this paper, we numerically study the instability of periodic planar traveling wave solution in two dimensions. The emergence of stable spiral pattern is observed in the considered model. This pattern occurs when the heart is malfunctioning (i.e., ventricular tachycardia). We show that the spiral wave breakup is a consequence of the transverse instability of the planar traveling wave solutions. The alternans, that is, the oscillation of pulse widths, is observed in our simulation results. Moreover, we calculate the widths of spiral pulses numerically and observe that the stable spiral pattern bifurcates to an oscillatory wave pattern in a one-parameter family of solutions. The spiral breakup occurs far below the bifurcation when the maximum and the minimum excited states become more distinct, and hence the alternans becomes more pronounced. |
12,302 | A study of ECG pattern, cardiac structural abnormalities and familial tendency in patients with early repolarisation syndrome in South India. | Early repolarisation (ER) on ECG, which was initially believed to be benign, has of late been considered otherwise. Brugada syndrome has recently been thought to be an extension of the ER spectrum, and the familial tendency of the ER pattern is being highlighted. With attention being drawn to ER's association with idiopathic ventricular fibrillation (VF), the prognosis and lineage of patients with an ER pattern are under scrutiny.</AbstractText>To analyse ER patterns on ECG, their presence in first-degree relatives and their association with structural heart disease. To classify different types of ER and estimate the prevalence of the high-risk notch/slur pattern in the population studied.</AbstractText>We screened all patients presenting to our department from December 2011 to July 2014 for ER patterns. We excluded patients with other causes of ST elevation that mimicked the ER pattern, those aged <18 years, and those not willing to participate in the study. A complete physical examination, 12-lead ECG and echocardiography were performed on all study patients. Willing first-degree relatives were screened with a 12-lead ECG. Of the 963 patients with ER that we initially screened, 843 completed the study. A total of 4116 relatives were screened.</AbstractText>Of the 843 patients who completed the study, 687 (81.5%) were male and 156 (18.5%) were female. The majority were asymptomatic (70.11%), but had been referred for ECG abnormalities. Fifteen patients with chest pain were inadvertently thrombolysed and were later diagnosed to have ER. Their ER pattern was exaggerated during chest pain, which made this error highly likely. Among the 48 patients who had acute coronary syndrome (ACS), ER pattern was noticed in a different lead than those affected by ACS. Of these, 27 (56.25%) had ventricular tachycardia/VF during the acute phase. Six patients had electrical storm without evidence of ACS, and all had a global ER pattern with prominent notching/slurring on baseline ECG. The most common type of ER pattern was type I (lateral leads; 55.87%). Twenty-one patients had a Brugada pattern. Of all the patients with ER, only a third (34.16%) had the possibly high-risk notched/slurred ECG pattern. The majority (82.92%) had a structurally normal heart. We found that mitral valve prolapse (MVP), as assessed by >2 mm leaflet prolapse from the annulus, was more common in patients with ER (11.39%). Of the 4116 relatives screened, 2625 (63.78%) had an ER pattern; a quarter of family members had the inferolateral variety and over 60% of relatives had the lateral variety. We also noticed different ER patterns in the same family.</AbstractText>We found that exaggeration of the ER pattern during chest pain may lead to inadvertent thrombolysis. A notched/slurred ER pattern is found in only a third of patients, who need to be grouped separately, as they may constitute a high-risk category. Patients with ER had MVP at a higher prevalence (almost double) than the general population, probably explaining the high incidence of sudden cardiac death associated with MVP. A familial tendency to an ER pattern was found in more than half of first-degree relatives, with different ER patterns, even the Brugada pattern, found in the same family. This may be because Brugada and other ER patterns belong to the same spectrum and may share the same prognosis. Thus we conclude that further studies regarding ER, its association with MVP, risk stratification by notched ECG pattern, and familial distribution along with gene analysis are warranted.</AbstractText> |
12,303 | Arterial stiffness determined according to the cardio-ankle vascular index is associated with paroxysmal atrial fibrillation: a cross-sectional study. | Several lines of evidence suggest that atrial fibrillation (AF) may be a consequence of vascular disease. We investigated the relationship between cardio-ankle vascular index (CAVI), a new index of arterial stiffness, and the presence of paroxysmal AF (PAF).</AbstractText>181 outpatients (91 patients with PAF and 90 age- and gender-matched subjects without PAF) were analysed for their sinus rhythm. The CAVI was significantly higher in patients with PAF than in subjects without PAF (9.0±1.0 vs 8.7±0.8, p<0.01). In all subjects, the CAVI was significantly correlated with the left ventricular mass index (r=0.30, p<0.01), left atrial diameter (r=0.22, p<0.01), and augmentation index, a parameter of wave reflection (r=0.32, p<0.01), in addition to age, systolic blood pressure and pulse pressure. Logistic analysis demonstrated that the CAVI was independently associated with PAF even after adjustment for confounding factors. The adjusted OR of PAF was 1.8 for each unit increase in the CAVI (p=0.01).</AbstractText>Our finding suggests that increased arterial stiffness may be involved in the maintenance of AF.</AbstractText> |
12,304 | Atrial fibrillation in ventricular-paced rhythm: under-recognised, underdiagnosed and potentially dangerous. | There is only scant published evidence demonstrating the importance of diagnosing atrial fibrillation (AF) in patients with a ventricularly paced rhythm. This potential pitfall to recognise AF has the implication of devastating outcomes.</AbstractText>A short survey was undertaken in order to gauge the ability of doctors of all grades to recognise AF, and adequate anticoagulation, in the patient with chronic right ventricular pacing (RVp), based on ECG interpretation. Participants were trainee doctors from different grades including foundation doctors, core medical trainee, specialist registrars and consultants.</AbstractText>Only 11.3% of doctors correctly identified the need for oral anticoagulation. There was no association between four groups (F1, F2, core medical training (CMT) and SpR) and incorrect answers (Fisher's exact test, value=4.082, p=0.252). However, there was a trend of better AF recognition towards registrar but this has not reached statistical significance.</AbstractText>Our study demonstrates severe systemic under-recognition of this fairly common condition among hospital doctors. This may lead to a lower rate of anticoagulation and a higher incidence of thromboembolic events.</AbstractText> |
12,305 | Predicting Survival with Good Neurological Outcome Within 24 Hours Following Out of Hospital Cardiac Arrest:The Application and Validation of a Novel Clinical Score. | Despite 50 years of research, prognostication post cardiac arrest traditionally occurs at 72 hours. We tested the accuracy of a novel bedside score within 24 hours of hospital admission, in predicting neurologically intact survival.</AbstractText>We studied 192 adults following non-traumatic out-of-hospital cardiac arrest. In a 50% random modeling sample, a model for survival to discharge with good neurological outcome was developed using univariate analysis and stepwise multivariate logistic regression for predictor selection. The diagnostic efficiency of this modeled score was assessed in the remaining 50% sample using receiver operating characteristic (ROC) analysis.</AbstractText>In this study, 20% of patients survived to discharge with good neurological outcome. The final logistic regression model in the modeling sample retained three predictors: initial rhythm Ventricular Fibrillation, Return of Spontaneous Circulation ≤ 20 minutes from collapse, and Brainstem Reflex Score ≥ 3 within 24 hours. These variables were used to develop a three-point Out of Hospital Cardiac Arrest score. The area under the (ROC) curve was 0.84 [95% CI, 0.75-0.93] in the modeling sample and 0.92 [95% CI, 0.87-0.98] in the validation sample. A score ≥ 2 predicted good neurological outcome with a sensitivity of 79%, a specificity of 92%, and a negative predictive value of 93%. A score ≥1 had a sensitivity of 100% and a negative predictive value of 100%; however, the specificity was only 55%.</AbstractText>This study demonstrates that a score based on clinical and easily accessible variables within 24 hours can predict neurologically intact survival following cardiac arrest.</AbstractText> |
12,306 | [Obesity and the prognosis of heart failure: the obesity paradox, myth or reality?]. | Obesity has now reached epidemic proportions worldwide. Obesity is associated with numerous comorbidities, including hypertension, lipid disorders and type II diabetes, and is also a major cause of cardiovascular disease, coronary disease, heart failure, atrial fibrillation, and sudden death. Obesity is the main cause of heart failure in respectively 11% and 14% of cases in men and women. The Framingham study showed that, after correction for other risk factors, each point increase in the body mass index raises the risk of heart failure by 5% in men and 7% in women. Obesity increases the heart workload, causes left ventricular hypertrophy, and impairs both diastolic and systolic function. The most common form of heart failure is diastolic dysfunction, and heart failure in obese individuals is associated with preserved systolic function. Despite these comorbidities and the severity of heart failure, numerous studies have revealed an "obesity paradox" in which overweight and obese individuals with heart failure appear to have a better prognosis than non overweight subjects. This review summarizes the adverse cardiac effects of this nutritional disease, the results of some studies supporting the obesity paradox, the better survival rate of obese patients with heart failure. Potential explanations for these surprising data include the possibility that a number of obese patients may simply not have heart failure, as well as methodological bias, and protective effects of adipose tissue. Further studies of large populations are needed to determine how obesity may improve the prognosis of heart failure. |
12,307 | Echocardiographic predictors of ventricular tachycardia. | Patients with structural heart disease are prone to ventricular tachycardia (VT) and ventricular fibrillation (VF), which account for the majority of sudden cardiac deaths (SCDs). We sought to examine echocardiographic parameters that can predict VT as documented by implantable cardioverter-defibrillator (ICD) appropriate discharge. We examine echocardiographic parameters other than ejection fraction that may predict VT as recorded via rates of ICD discharge.</AbstractText>Analysis of 586 patients (469 males; mean age = 68 ± 3 years; mean follow-up time of 11 ± 14 months) was undertaken. Echo parameters assessed included left ventricular (LV) internal end diastolic/systolic dimension (LVIDd, LVIDs), relative wall thickness (RWT), and left atrial (LA) size.</AbstractText>The incidence of VT was 0.22 (114 VT episodes per 528 person-years of follow-up time). Median time-to-first VT was 3.8 years. VT was documented in 79 patients (59 first VT incidence, 20 multiple). The echocardiographic parameter associated with first VT was LVIDs >4 cm (P = 0.02).</AbstractText>The main echocardiographic predictor associated with the first occurrence of VT was LVIDs >4 cm. Patients with an LVIDs >4 cm were 2.5 times more likely to have an episode of VT. Changes in these echocardiographic parameters may warrant aggressive pharmacologic therapy and implantation of an ICD.</AbstractText> |
12,308 | Psoriasis is associated with subsequent atrial fibrillation in hypertensive patients with left ventricular hypertrophy: the Losartan Intervention For Endpoint study. | Inflammation contributes to the pathogenesis of psoriasis as well as atrial fibrillation. The impact of psoriasis and its association with new-onset atrial fibrillation was assessed in hypertensive patients with left ventricular hypertrophy (LVH).</AbstractText>The predictive value of baseline or incident psoriasis for new-onset atrial fibrillation was evaluated in 7099 hypertensive patients with electrocardiographic LVH with no history of atrial fibrillation or other cardiovascular disease, in sinus rhythm on their baseline electrocardiogram.</AbstractText>A total of 154 patients (2.2%) had or developed psoriasis and new-onset atrial fibrillation occurred in 506 patients (7.1%) during a mean follow-up of 4.7 ± 1.1 years. At baseline, the psoriasis patients were younger (65 ± 7 vs. 67 ± 7 years) and had less left ventricle hypertrophy by ECG Sokolow-Lyon voltage (27.6 ± 9.7 vs. 30.1 ± 10.4 mm); higher hemoglobin (6.3 ± 2.2 vs. 6.0 ± 2.7 mmol/l) and prevalence of diabetes (20.6 vs. 12.8%, P ≤ 0.004) than patients without psoriasis. In multivariable Cox analysis, adjusting for age, sex, hemoglobin, diabetes, time-varying SBP, heart rate, study treatment and Sokolow-Lyon hypertrophy, psoriasis, treated as a time-varying covariate, was associated with a two-fold higher risk of new-onset atrial fibrillation [hazard ratio: 1.97 (95% confidence interval (CI): 1.18-3.30), P=0.01]. Propensity-matched analysis yielded similar results (odds ratio: 3.49, 95% CI 1.24-9.81, P=0.018).</AbstractText>Psoriasis has a similar prevalence in hypertensive patients as in the general population. Psoriasis independently predicted new-onset atrial fibrillation despite lower age and electrocardiographic LVH in psoriasis patients than in patients without psoriasis.</AbstractText> |
12,309 | Hypokalemia promotes late phase 3 early afterdepolarization and recurrent ventricular fibrillation during isoproterenol infusion in Langendorff perfused rabbit ventricles. | Hypokalemia and sympathetic activation are commonly associated with electrical storm (ES) in normal and diseased hearts. The mechanisms remain unclear.</AbstractText>The purpose of this study was to test the hypothesis that late phase 3 early afterdepolarization (EAD) induced by IKATP activation underlies the mechanisms of ES during isoproterenol infusion and hypokalemia.</AbstractText>Intracellular calcium (Cai) and membrane voltage were optically mapped in 32 Langendorff-perfused normal rabbit hearts.</AbstractText>Repeated episodes of electrically induced ventricular fibrillation (VF) at baseline did not result in spontaneous VF (SVF). During isoproterenol infusion, SVF occurred in 1 of 15 hearts (7%) studied in normal extracellular potassium ([K(+)]o, 4.5 mmol/L), 3 of 8 hearts (38%) in 2.0 mmol/L [K(+)]o, 9 of 10 hearts (90%) in 1.5 mmol/L [K(+)]o, and 7 of 7 hearts (100%) in 1.0 mmol/L [K(+)]o (P <.001). Optical mapping showed that isoproterenol and hypokalemia enhanced Cai transient duration (CaiTD) and heterogeneously shortened action potential duration (APD) after defibrillation, leading to late phase 3 EAD and SVF. IKATP blocker (glibenclamide, 5 μmol/L) reversed the post-defibrillation APD shortening and suppressed recurrent SVF in all hearts studied despite no evidence of ischemia. Nifedipine reliably prevented recurrent VF when given before, but not after, the development of VF. IKr blocker (E-4031) and small-conductance calcium-activated potassium channel blocker (apamin) failed to prevent recurrent SVF.</AbstractText>Beta-adrenergic stimulation and concomitant hypokalemia could cause nonischemic activation of IKATP, heterogeneous APD shortening, and prolongation of CaiTD to provoke late phase 3 EAD, triggered activity, and recurrent SVF. IKATP inhibition may be useful in managing ES during resistant hypokalemia.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,310 | Mechanisms underlying the development of the electrocardiographic and arrhythmic manifestations of early repolarization syndrome. | Early repolarization pattern in the ECG has been associated with increased risk for ventricular tachycardia/fibrillation (VT/VF), particularly when manifest in inferior leads. This study examines the mechanisms underlying VT/VF in early repolarization syndrome (ERS). Transmembrane action potentials (APs) were simultaneously recorded from 2 epicardial sites and 1 endocardial site of coronary-perfused canine left-ventricular (LV) wedge preparations, together with a pseudo-ECG. Transient outward current (Ito) was recorded from epicardial myocytes isolated from the inferior and lateral LV of the same heart. J wave area (pseudo-ECG), epicardial AP notch magnitude and index were larger in inferior vs. lateral wall preparations at baseline and after exposure to provocative agents (NS5806+verapamil+acetylcholine (ACh)). Ito density was greater in myocytes from inferior vs. lateral wall (18.4 ± 2.3pA/pF vs. 11.6 ± 2.0pA/pF; p<0.05). A combination of NS5806 (7 μM) and verapamil (3 μM) or pinacidil (4 μM), used to pharmacologically model the genetic defects responsible for ERS, resulted in prominent J-point and ST-segment elevation. ACh (3 μM), simulating increased vagal tone, precipitated phase-2-reentry-induced polymorphic VT/VF. Using identical protocols, inducibility of arrhythmias was 3-fold higher in inferior vs. lateral wedges. Quinidine (10 μM) or isoproterenol (1 μM) restored homogeneity and suppressed VT/VF. Our data support the hypothesis that 1) ERS is caused by a preferential accentuation of the AP notch in the LV epicardium; 2) this repolarization defect is accentuated by elevated vagal tone; 3) higher intrinsic levels of Ito account for the greater sensitivity of the inferior LV wall to development of VT/VF; and 4) quinidine and isoproterenol exert ameliorative effects by reversing the repolarization abnormality. |
12,311 | Retrograde flush is more protective than heparin in the uncontrolled donation after circulatory death lung donor. | Formation of microthrombi after circulatory arrest is a concern for the development of reperfusion injury in lung recipients from donation after circulatory death (DCD) donors. In this isolated lung reperfusion study, we compared the effect of postmortem heparinization with preharvest retrograde pulmonary flush or both.</AbstractText>Domestic pigs (n = 6/group) were sacrificed by ventricular fibrillation and left at room temperature for 1 h. This was followed by 2.5 h of topical cooling. In control group [C], no heparin and no pulmonary flush were administered. In group [R], lungs were flushed with Perfadex in a retrograde way before explantation. In group [H], heparin (300 IU/kg) was administered 10 min after cardiac arrest followed by closed chest massage for 2 min. In the combined group, animals were heparinized and the lungs were explanted after retrograde flush [HR]. The left lung was assessed for 60 min in an ex vivo reperfusion model.</AbstractText>Pulmonary vascular resistance at 50 and 55 min was significantly lower in [R] and [HR] groups compared with [C] and [H] groups (P < 0.01 and P < 0.001) and at 60 min in [R], [H], and [HR] groups compared with [C] group (P < 0.001). Oxygenation, compliance, and plateau airway pressure were more stable in [R] and [HR] groups. Plateau airway pressure was significantly lower in [R] group compared with the [H] group at 60 min (P < 0.05). No significant differences in wet-dry weight ratio were observed between the groups.</AbstractText>This study suggests that preharvest retrograde flush is more protective than postmortem heparinization to prevent reperfusion injury in lungs recovered from donation after circulatory death donors.</AbstractText>Copyright © 2014 Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,312 | Advances in modeling ventricular arrhythmias: from mechanisms to the clinic. | Modern cardiovascular research has increasingly recognized that heart models and simulation can help interpret an array of experimental data and dissect important mechanisms and interrelationships, with developments rooted in the iterative interaction between modeling and experimentation. This article reviews the progress made in simulating cardiac electrical behavior at the level of the organ and, specifically, in the development of models of ventricular arrhythmias and fibrillation, as well as their termination (defibrillation). The ability to construct multiscale models of ventricular arrhythmias, representing integrative behavior from the molecule to the entire organ, has enabled mechanistic inquiry into the dynamics of ventricular arrhythmias in the diseased myocardium, in understanding drug-induced proarrhythmia, and in the development of new modalities for defibrillation, to name a few. In this article, we also review the initial use of ventricular models of arrhythmia in personalized diagnosis, treatment planning, and prevention of sudden cardiac death. Implementing individualized cardiac simulations at the patient bedside is poised to become one of the most thrilling examples of computational science and engineering approaches in translational medicine. |
12,313 | Long-term follow-up after atrial fibrillation ablation in patients with impaired left ventricular systolic function: the importance of rhythm and rate control. | Atrial fibrillation (AF) ablation is increasingly used in patients with reduced left ventricular ejection fraction (LVEF), but long-term outcomes are still unknown.</AbstractText>To assess the long-term effects of AF ablation in patients with systolic heart failure according to rhythm outcome.</AbstractText>We included 69 patients with LVEF ≤40%, referred for circumferential pulmonary vein isolation with or without additional substrate modification to our institution in 2006-2010. Follow-up included 7-day Holter electrocardiography and echocardiography at baseline and at 6, 12, and 24 months after ablation. A matched control group (n = 69) after AF ablation without heart failure was used for comparison.</AbstractText>After 28 ± 11 months and 1.6 ± 0.7 ablation procedures, 45 (65%) patients were still in the stable sinus rhythm (SSR) group. LVEF increased from 33 ± 6% to 53 ± 11% (P < .001) in the SSR group and from 33 ± 5% to 38 ± 12% (P = .03) in patients with recurrences (atrial tachycardia/fibrillation group). While LVEF increase was similar in the 2 groups at 6 months (15 ± 12% vs 8 ± 11%; P = .2), further LVEF improvements were observed in the SSR group only. Adjustments for baseline characteristics revealed that the increase in LVEF at 6 months was associated with higher baseline heart rate and not with rhythm outcome. Heart rate did not change in either group after 6 months of follow-up. Complications and procedural data of the study group were similar to the control group.</AbstractText>In patients with heart failure undergoing AF ablation, there is an initial short-term LVEF improvement related to baseline heart rate. However, long-term LVEF improvement is associated with rhythm outcome.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,314 | Genetic variation in the two-pore domain potassium channel, TASK-1, may contribute to an atrial substrate for arrhythmogenesis. | The two-pore domain potassium channel, K2P3.1 (TASK-1) modulates background conductance in isolated human atrial cardiomyocytes and has been proposed as a potential drug target for atrial fibrillation (AF). TASK-1 knockout mice have a predominantly ventricular phenotype however, and effects of TASK-1 inactivation on atrial structure and function have yet to be demonstrated in vivo. The extent to which genetic variation in KCNK3, that encodes TASK-1, might be a determinant of susceptibility to AF is also unknown. To address these questions, we first evaluated the effects of transient knockdown of the zebrafish kcnk3a and kcnk3b genes and cardiac phenotypes were evaluated using videomicroscopy. Combined kcnk3a and kcnk3b knockdown in 72 hour post fertilization embryos resulted in lower heart rate (p<0.001), marked increase in atrial diameter (p<0.001), and mild increase in end-diastolic ventricular diameter (p=0.01) when compared with control-injected embryos. We next performed genetic screening of KCNK3 in two independent AF cohorts (373 subjects) and identified three novel KCNK3 variants. Two of these variants, present in one proband with familial AF, were located at adjacent nucleotides in the Kozak sequence and reduced expression of an engineered reporter. A third missense variant, V123L, in a patient with lone AF, reduced resting membrane potential and altered pH sensitivity in patch-clamp experiments, with structural modeling predicting instability in the vicinity of the TASK-1 pore. These in vitro data suggest that the double Kozak variants and V123L will have loss-of-function effects on ITASK. Cardiac action potential modeling predicted that reduced ITASK prolongs atrial action potential duration, and that this is potentiated by reciprocal changes in activity of other ion channel currents. Our findings demonstrate the functional importance of ITASK in the atrium and suggest that inactivation of TASK-1 may have diverse effects on atrial size and electrophysiological properties that can contribute to an arrhythmogenic substrate. |
12,315 | [Analysis of risk factors for all cause-mortality in Chinese emergency atrial fibrillation patients]. | To explore the independent risk factors associated with one-year mortality in patients with atrial fibrillation (AF).</AbstractText>This study consecutively enrolled AF patients presenting to an emergency department at 20 Chinese hospitals from November 2008 to October 2011. Their baseline data and therapies were recorded. They were followed up for one year. Their major cardiovascular outcomes were recorded. And the predictors of one-year mortality were identified by uni- and multi-variate Cox regression analysis with baseline, therapy variables and follow-up therapy variables.</AbstractText>The one-year all-cause mortality was 13.8% among a total of 2016 AF patients. They were divided into mortality group (A, n = 279) and survival group (B, n = 1737). The baseline data of two groups were analyzed. The group A patients were older ((76.1 ± 11.6) vs (67.2 ± 13.1) years, P < 0.01) and had smaller body mass index compared with group B ((23.7 ± 3.6) vs (22.3 ± 3.4) kg/m(2), P < 0.01); the proportion of permanent AF and CHADS2 score ≥ 2 points was higher in the group A (71.8% vs 47.5%, P < 0.01). History of heart failure, previous stroke, left ventricular systolic dysfunction, diabetes, dementia and chronic obstructive pulmonary disease (COPD) were in a higher proportion of group A (51.2% vs 35.1%, 26.3% vs 17.6%, 26.7% vs 17.9%, 21.0% vs 14.6%, 6.0% vs 1.6%, 21.4% vs 10.1%, all P < 0.01). With regards to drug treatment, usage of diuretics, digoxin and other anticoagulants (heparin, etc), the values were greater in group A (50.9% vs 42.2%, 41.3% vs 34.7%, 10.0% vs 5.9%, all P < 0.01). The Kaplan-Meier survival curves showed that the mortality rate increased along with rising CHADS2 score. Multi-variate Cox regression analysis showed that age (HR = 1.053, 95%CI: 1.040-1.066), permanent AF (HR = 1.374, 95%CI: 1.003-1.883), history of heart failure (HR = 1.385, 95%CI: 1.009-1.901), previous stroke (HR = 1.345, 95%CI: 1.009-1.795), COPD (HR = 1.379, 95%CI: 1.030-1.848), unused angiotensin II receptor blocker (ARB) (HR = 1.955, 95%CI: 1.349-2.832), aspirin unused (HR = 1.770, 95%CI: 1.375-2.278) and warfarin unused (HR = 3.262, 95%CI:1.824-5.834) were independent risk factors for one-year mortality of AF patients.</AbstractText>Age, history of heart failure, previous stroke, COPD history, ARB unused, aspirin and warfarin unused are independent risk factors for one-year all-cause mortality of AF patients.</AbstractText> |
12,316 | Left atrial remodeling and recurrence of congestive heart failure in patients initially diagnosed with heart failure. | Left atrial volumes (LAVs) have been suggested to represent long-term exposure to elevated pressures. This study examined the recurrence of heart failure (HF) based on LAV in patients initially diagnosed with congestive HF (CHF).</AbstractText>This study comprised 77 patients (age, 75 ± 8 years) with well-documented, clinically defined HF, and complete two-dimensional echocardiographic examinations. The echocardiographic examinations were performed on admission and after medical treatment (90 ± 43 days after initial examination). Patients with atrial fibrillation, flail mitral valve, or mitral valve replacement were excluded from this study.</AbstractText>The initial left ventricular ejection fraction (LVEF) was 44 ± 17% and the indexed LAV (LAVI) was 61 ± 22 mL/m(2) . After medical treatment, a decreased LAVI was observed in 38 patients and an increased LAVI (LA remodeling) was observed in 39 patients. With median follow-up periods of 454 days, compared to patients with decreased LAVI, patients with LA remodeling had a significantly higher incidence of CHF recurrence (P = 0.008). Patients with LA remodeling had a CHF-free survival rate of 36 ± 13% vs. 81 ± 9% (those without LA remodeling). A multivariate analysis indicated that, follow-up LV end-systolic volume (P = 0.04), LVEF (P = 0.005) and LAVI (P = 0.04) independently predicted CHF recurrence.</AbstractText>Patients initially diagnosed with CHF follow divergent courses based on their LAV. LA remodeling after medical treatment can be useful for predicting CHF recurrence during follow-up.</AbstractText>© 2013, Wiley Periodicals, Inc.</CopyrightInformation> |
12,317 | RV-only pacing can produce a Q wave in lead 1 and an R wave in V1: implications for biventricular pacing. | Biventricular (bi-v) pacing improves congestive heart failure and mortality in patients with left ventricular (LV) dysfunction and electrical dyssynchrony. Effective resynchronization must include an LV pacing contribution to the QRS. Leads 1 and V1 are often exclusively used to verify proper biventricular pacing.</AbstractText>In 40 patients referred to our cardiac resynchronization therapy (CRT) optimization clinic, 12-lead electrocardiograms (ECGs) were obtained during bi-v pacing, right ventricular (RV)-only pacing, LV-only pacing, and a range of atrio-ventricular and ventriculo-ventricular intervals. The presenting bi-v QRS morphology was compared to RV and LV pacing, and RV-only pacing was evaluated for the presence of a Q wave in lead 1 and an R wave in V1.</AbstractText>In 22 patients (55%), RV pacing produced an initial Q wave in lead 1 and/or R wave in V1, mimicking bi-v pacing. In three patients, the presenting bi-v paced ECG looked identical to RV-only pacing. In 28 patients (70%), LV pacing was advanced by a mean of 30 ms after CRT optimization. Using all 12 ECG leads, especially the precordial leads, was necessary to appreciate the QRS changes that occurred when LV pacing meaningfully contributed to electrical activation.</AbstractText>Because of LV pacing latency, some patients require an earlier LV offset to achieve proper resynchronization pacing. Commonly used ECG criteria cannot verify meaningful LV pacing contribution during biventricular pacing because RV-only pacing often creates a Q wave in lead 1 and/or R wave in V1. The full 12-lead ECG during biventricular pacing should be compared with isolated RV and LV pacing to verify that LV pacing is properly contributing to the QRS.</AbstractText>©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,318 | Cardiac Events Theoretically Cannot Be Produced By Non-Ischemic And/Or Iso-Ischemic Myocardium: Challenging Postulations And Vitality Of The Concept Of "Ischemia-Dependent Conflictogenic Arrhythmias". | Ischemia plays a key role in cardiac arrhythmogenesis, particularly in elderly patients. Healthy, non-ischemic and structurally normal myocardium is universally free from dysrhythmias. Thereby intact coronary blood flow prevents potential cardiac events. Hypothetically, ischemia-related electrophysiological differences are responsible for the supraventricular and/or ventricular rhythm irregularities. The goal of this review is to determine the role of systemic and coronary circulatory peculiarities and their association with heart rhythm abnormalities. The current analytical review extends and enriches previous knowledge about the influence of these peculiarities on the genesis of ischemia-dependent conflictogenic arrhythmias. Different intensity of coronary blood flow resulting from stenotic obstacles or vasospasm potentially leads to the non-uniform perfusion of myocites thus creating albeit subtle but vulnerable and powerful electrophysiologic substrate impending cardiac rhythm disturbances. Apparently, the behavior of both non-ischemic and iso-ischemic myocardium in respect to electric cardiac activity is very similar, at least theoretically. Some different clinical entities, e.g. arterial hypotension and/or anemia containing ischemic component, in most cases are free from arrhythmias. This postulation may be helpful in furthering arrhythmogenicity insights which have been generated previously. On the contrary, increased blood pressure often concurs with the supraventricular and/or ventricular arrhythmias; this pattern also favorably reflects our previous hypothetical assumptions associated with the mechanisms of arrhythmogenesis. Conclusively, both non-ischemic and iso-ischemic myocardium may be attributed to nonarrhythmogenic milieu. Nevertheless, the inventive analysis and more explorative data are required to support the suggested postulations. |
12,319 | Presence of A Left Atrial Appendage Thrombus After Successful Surgical Closure of the Left Atrial Appendage: A Case Report. | A 64-year-old African American woman presented for defibrillator threshold testing (DFTs) after a recent hospitalization for ventricular fibrillation terminated by her ICD. She had a known history of non-ischemic cardiomyopathy, atrial fibrillation, rheumatic mitral valve disease s/p mitral valve replacement and a redo after subsequent endocarditis. In preparation for the DFTs, the patient underwent a transesophageal echocardiogram (TEE) to rule our left atrial (LA) or LA appendage thrombus. Patient was found to have a surgically closed appendage. Within the body of the closed appendage, a mobile thrombus was seen with clot free areas surrounding the thrombus. Doppler and contrast studies confirmed that there was no communication between the LA and the appendage. The patient underwent DFTs without complication and a follow-up TEE confirmed the presence of the clot in the non-communicating LA appendage. |
12,320 | Ablation of idiopathic ventricular fibrillation triggered by ventricular premature beat originating from myocardium of right ventricle: Case report. | We report a case of a 55-year-old woman with idiopathic ventricular fibrillation (VF) who suffered from recurrent implantable cardioverter-defibrillator shocks triggered by short coupled ventricular premature beat (VPB). This VPB was mapped and ablated from the myocardium of right ventricle close to the lateral tricuspid annulus. <<b>Learning objective:</b> Triggering ventricular premature beat (VPB) in idiopathic ventricular fibrillation was reported to originate from the myocardium of right ventricular outflow tract or from Purkinje system. In this case, the origin of triggering VPB is the myocardium of right ventricle close to the lateral tricuspid annulus.>. |
12,321 | Combination of epinephrine with esmolol attenuates post-resuscitation myocardial dysfunction in a porcine model of cardiac arrest. | Recent experimental and clinical studies have indicated that the β-adrenergic effect of epinephrine significantly increases the severity of post resuscitation myocardial dysfunction. The aim of the study was to investigate whether the short-acting β₁-selective adrenergic blocking agent, esmolol, would attenuate post resuscitation myocardial dysfunction in a porcine model of cardiac arrest.</AbstractText>After 8 min of untreated ventricular fibrillation and 2 min of basic life support, 24 pigs were randomized to three groups (n = 8 per group), which received central venous injection of either epinephrine combined with esmolol (EE group), epinephrine (EP group), or saline (SA group). Hemodynamic status and blood samples were obtained at 0, 30, 60, 120, 240 and 360 min after return of spontaneous circulation (ROSC). Surviving pigs were euthanatized at 24 h after ROSC, and the hearts were removed for analysis by electron microscopy, Western blotting, quantitative real-time polymerase chain reaction, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Compared with the EP and SA groups, EE group had a better outcome in hemodynamic function, (improved dp/dt maxima and minima and cardiac output) (P<0.05), and improved oxygen metabolism (oxygen delivery and oxygen consumption) (P<0.05), which suggesting that EE can protect myocardial tissue from injury and improve post-resuscitation myocardial dysfunction. The protective effect of EE also correlated with reducing cardiomyocyte apoptosis, evidenced by reducing TUNEL-positive cells, increasing anti-apoptotic Bcl-2/Bax ratio and suppression of caspase-3 activity in myocardium.</AbstractText>Esmolol, a short-acting β₁-selective adrenergic blocking agent, given during CPR has significant effects on attenuating post resuscitation myocardial dysfunction. The current study provides a potential pharmacologic target for post resuscitation myocardial dysfunction.</AbstractText> |
12,322 | Role of ATP-sensitive K+ channels in cardiac arrhythmias. | The sarcolemmal adenosine triphosphate (ATP)-sensitive K(+) (sarcKATP) channel in the heart is a hetero-octamer comprising the pore-forming subunit Kir6.2 and the regulatory subunit sulfonylurea receptor SUR2A. By functional analysis of genetically engineered mice lacking sarcKATP channels, the pathophysiological roles of the K(+) channel in the heart have been extensively evaluated. Although mitochondrial KATP (mitoKATP) channel is proposed to be an important effector for the protection of ischemic myocardium and the inhibition of ischemia/reperfusion-induced ventricular arrhythmias, the molecular identity of mitoKATP channel has not been established. Although selective sarcKATP-channel blockers can prevent ischemia/reperfusion-induced ventricular arrhythmias by inhibiting the action potential shortening in the acute phase, the drugs may aggravate the ischemic damages due to intracellular Ca(2+) overload. The sarcKATP channel is also mandatory for optimal adaptation to hemodynamic stress such as sympathetic activation. Dysfunction of mutated sarcKATP channels in atrial cells may lead to electrical instability and atrial fibrillation. Recently, it has been proposed that the gain-of-function mutation of cardiac Kir6.1 channel can be a pathogenic substrate for J wave syndromes, a cause of idiopathic ventricular fibrillation as early repolarization syndrome or Brugada syndrome, whereas loss of function of the channel mutations can underlie sudden infant death syndrome. However, precise role of Kir6.1 channels in cardiac cells remains to be defined and further study may be needed to clarify the role of Kir6.1 channel in the heart. |
12,323 | Flaccid quadriplegia due to thyrotoxic myopathy. | Acute flaccid paralysis is an important clinical problem in neurological critical care. After implementing life-supporting measures, it is imperative to identify the correct diagnosis to provide timely appropriate care. Thyrotoxicosis is a recognized cause of myopathy, but rarely of quadriplegia. Here, we report a case of hyperthyroidism with severe weakness.</AbstractText>Case report and video demonstration of clinical examination.</AbstractText>We describe a case of a 59-year-old woman with Grave's disease who presented to the hospital with progressive shortness of breath secondary to atrial fibrillation with rapid ventricular response. Following contrast administration, she had a pulseless electrical activity arrest from which she recovered without cognitive sequelae, but with flaccid quadriplegia, facial diplegia, and hypophonia. CK was mildly elevated and electrolytes were essentially normal. Nerve conduction studies and electromyography demonstrated features supporting an acute myopathy without evidence of neuromuscular junction conduction abnormality.</AbstractText>Normalization of thyroid hormones resulted in slow, but steady improvement over months after which she regained ambulation. Acute flaccid quadriplegia can result from thyrotoxicosis. With normalization of thyroid function, recovery can be expected.</AbstractText> |
12,324 | Altered responses to vasopressors of a patient medicated with carvedilol, pilsicainide and enalapril. | A patient scheduled for laparoscopic rectal surgery was medicated with carvedilol, an antagonist of beta 1-, beta 2- and alpha 1-adrenergic receptors, pilsicainide, a class Ic antiarrhythmic drug and enalapril, an angiotensin-converting enzyme inhibitor. Because the patient experienced attacks of atrial fibrillation with rapid ventricular response almost weekly, carvedilol and pilsicainide were continued up to the day of surgery, while enalapril was discontinued for 24 h prior to surgery. During the operation, he showed prolonged hypotension that did not respond to usual doses of vasopressors such as ephedrine, phenylephrine and dopamine but responded to higher doses of norepinephrine. Postoperatively, he was given dopamine but exhibited tachyarrhythmia until the dopamine infusion was discontinued. |
12,325 | Neurologic complications of cardiomyopathies and other myocardial disorders. | Cardiomyopathies have a variety of causes: infectious, genetic, valvular heart disease, coronary artery disease, hypertension, and tachycardias. All can result in myocardial dysfunction and often congestive heart failure. The main interaction between a diagnosis of heart disease and the brain is via embolic stroke. The focus here is on myocardial dysfunction. Thrombus is associated with myocardial dysfunction and depressed left ventricular ejection fractions. Reduced left ventricular ejection fractions and mural thrombus are associated with embolic strokes. Atrial fibrillation is a primary source of thrombi. Anticoagulation can significantly reduce the incidence of thrombotic problems. Patent foramen ovale has created interest in those patients with cryptogenic strokes. Cryptogenic strokes are associated with patent foramen ovales, although not all cryptogenic strokes are associated with paradoxical emboli. Clinically silent cerebral infarctions occur in patients with dilated cardiomyopathy as detected by multidetector computed tomography or magnetic resonance imaging studies. Left ventricular dysfunction from cardiomyopathies is associated with mural thrombi, but the prevalence of embolic stroke varies widely from 3% to 50%; as many as half of embolic strokes are related to atrial fibrillation. Nonvalvular atrial fibrillation can increase the risk of stroke by a factor four to seven times when compared to normal sinus rhythm. Stroke risks and bleeding risks with anticoagulation can be estimated by scores. Genetic abnormalities are increasing in importance in helping to find the etiology and inheritance of some dilated cardiomyopathies. Careful clinical evaluation remains important. |
12,326 | Neurologic complications of valvular heart disease. | Valvular heart disease (VHD) is frequently associated with neurologic complications; cerebral embolism is the most common of these since thrombus formation results from the abnormalities in the valvular surfaces or from the anatomic and physiologic changes associated with valve dysfunction, such as atrial or ventricular enlargement, intracardiac thrombi, and cardiac dysrhythmias. Prosthetic heart valves, particularly mechanical valves, are very thrombogenic, which explains the high risk of thromboembolism and the need for anticoagulation for the prevention of embolism. Infective endocarditis is a disease process with protean manifestations that include not only cerebral embolism but also intracranial hemorrhage, mycotic aneurysms, and systemic manifestations such as fever and encephalopathy. Other neurologic complications include nonbacterial thrombotic endocarditis, a process associated with systemic diseases such as cancer and systemic lupus erythematosus. For many of these conditions, anticoagulation is the mainstay of treatment to prevent cerebral embolism, therefore it is the potential complications of anticoagulation that can explain other neurologic complications in patients with VHD. The prevention and management of these complications requires an understanding of their natural history in order to balance the risks posed by valvular disease itself against the risks and benefits associated with treatment. |
12,327 | Intrapericardial delivery of amiodarone rapidly achieves therapeutic levels in the atrium. | Amiodarone is widely used worldwide as an important drug for managing supraventricular arrhythmias, regardless of its association with potentially severe side effects due to systemic toxicity. Amiodarone reduces the incidence of atrial fibrillation after cardiac surgery, but oral therapy requires a presurgery loading period, lasting from 1 to 4 weeks. In this study, we showed that it is possible to rapidly obtain therapeutic cardiac tissue levels of the drug by infusing aqueous amiodarone intrapericardially, without appreciable systemic exposure. We also examined the long-term histologic safety of intrapericardial infusion.</AbstractText>In this observational study, 9 adult sheep, randomized into 3 groups of 3 animals each, were given low (2.5 -mg/h), medium (10-mg/h), or high (50-mg/h) dosages of amiodarone by continuous infusion intrapericardially for 72 hours. An intrapericardial drain prevented tamponade from fluid build-up. Levels of amiodarone and its active metabolite, desethylamiodarone (DEA), were assessed both in plasma and in transmural biopsy specimens taken from the left atrial appendage and left and right ventricular myocardium. Cardiac, hepatic, and renal functions were also assessed. Humane euthanization was performed after 3 months, and cardiac and thoracic tissues were assessed for evidence of epicarditis, severe fibrotic changes, or other adverse effects potentially caused by the local amiodarone administration.</AbstractText>Pericardial infusion resulted in rapid uptake and high concentrations of amiodarone and DEA in the myocardial tissues, without an appreciable systemic presence of either drug. The highest and lowest levels of these agents were observed in the left atrium and left ventricle, respectively. Drug concentrations in all cardiac biopsy specimens were similar to, or higher than, those reportedly observed in patients taking long-term oral amiodarone. At 90 days, postmortem microscopic, biochemical, and hematologic evaluation of end-organ tissues from the 8 surviving sheep showed no adverse effects. Excessive inflammation or fibrotic changes were not observed in these 8 sheep. The ninth sheep died prematurely, and its death was deemed not to be related to this study.</AbstractText>Short-term intrapericardial delivery of amiodarone is a safe method for rapidly obtaining therapeutic atrial-tissue drug levels. When begun perioperatively, this method may prevent postoperative atrial fibrillation similarly to oral or intravenous amiodarone therapy. However, we have shown that pericardial administration avoids systemic drug distribution and thus may greatly decrease the systemic complicationsresulting from this drug.</AbstractText> |
12,328 | Even four minutes of poor quality of CPR compromises outcome in a porcine model of prolonged cardiac arrest. | Untrained bystanders usually delivered suboptimal chest compression to victims who suffered from cardiac arrest in out-of-hospital settings. We therefore investigated the hemodynamics and resuscitation outcome of initial suboptimal quality of chest compressions compared to the optimal ones in a porcine model of cardiac arrest.</AbstractText>Fourteen Yorkshire pigs weighted 30 ± 2 kg were randomized into good and poor cardiopulmonary resuscitation (CPR) groups. Ventricular fibrillation was electrically induced and untreated for 6 mins. In good CPR group, animals received high quality manual chest compressions according to the Guidelines (25% of animal's anterior-posterior thoracic diameter) during first two minutes of CPR compared with poor (70% of the optimal depth) compressions. After that, a 120-J biphasic shock was delivered. If the animal did not acquire return of spontaneous circulation, another 2 mins of CPR and shock followed. Four minutes later, both groups received optimal CPR until total 10 mins of CPR has been finished.</AbstractText>All seven animals in good CPR group were resuscitated compared with only two in poor CPR group (P < 0.05). The delayed optimal compressions which followed 4 mins of suboptimal compressions failed to increase the lower coronary perfusion pressure of five non-survival animals in poor CPR group.</AbstractText>In a porcine model of prolonged cardiac arrest, even four minutes of initial poor quality of CPR compromises the hemodynamics and survival outcome.</AbstractText> |
12,329 | Levosimendan: current data, clinical use and future development. | Levosimendan is an inodilator indicated for the short-term treatment of acutely decompensated severe chronic heart failure, and in situations where conventional therapy is not considered adequate. The principal pharmacological effects of levosimendan are (a) increased cardiac contractility by calcium sensitisation of troponin C, (b) vasodilation, and (c) cardioprotection. These last two effects are related to the opening of sarcolemmal and mitochondrial potassium-ATP channels, respectively. Data from clinical trials indicate that levosimendan improves haemodynamics with no attendant significant increase in cardiac oxygen consumption and relieves symptoms of acute heart failure; these effects are not impaired or attenuated by the concomitant use of beta-blockers. Levosimendan also has favourable effects on neurohormone levels in heart failure patients. Levosimendan is generally well tolerated in acute heart failure patients: the most common adverse events encountered in this setting are hypotension, headache, atrial fibrillation, hypokalaemia and tachycardia. Levosimendan has also been studied in other therapeutic applications, particularly cardiac surgery - in which it has shown a range of beneficial haemodynamic and cardioprotective effects, and a favourable influence on clinical outcomes - and has been evaluated in repetitive dosing protocols in patients with advanced chronic heart failure. Levosimendan has shown preliminary positive effects in a range of conditions requiring inotropic support, including right ventricular failure, cardiogenic shock, septic shock, and Takotsubo cardiomyopathy. |
12,330 | Current concepts for minimally invasive mitral valve repair. | Minimally invasive mitral valve repair is based on several procedural concepts. Recently, three of them have been intensively discussed: aortic occlusion strategy, use of Goretex-Neo-Chordae to repair mitral valve regurgitation and feasibility and efficacy of the minithoracotomy approach in mitral valve treatment of patients after previous cardiac surgery. Twenty years of experience in minimally invasive mitral valve repair have enabled high-volume centers to present valid data and give their recommendations. Transthoracic aortic clamping with ante- and retrograde cardioplegia in the primary setting and hypothermic fibrillation in reoperative setting are currently favoured means of myocardial protection. Neo-chordae concept of mitral valve repair has gained general recognition and has become the technique of choice for many surgeons. The excellent results of minimally invasive mitral valve repair must be considered whenever already available or any new transcatheter techniques are offered. |
12,331 | Functional characterization of a novel frameshift mutation in the C-terminus of the Nav1.5 channel underlying a Brugada syndrome with variable expression in a Spanish family. | We functionally analyzed a frameshift mutation in the SCN5A gene encoding cardiac Na(+) channels (Nav1.5) found in a proband with repeated episodes of ventricular fibrillation who presented bradycardia and paroxysmal atrial fibrillation. Seven relatives also carry the mutation and showed a Brugada syndrome with an incomplete and variable expression. The mutation (p.D1816VfsX7) resulted in a severe truncation (201 residues) of the Nav1.5 C-terminus.</AbstractText>Wild-type (WT) and mutated Nav1.5 channels together with hNavβ1 were expressed in CHO cells and currents were recorded at room temperature using the whole-cell patch-clamp. Expression of p.D1816VfsX7 alone resulted in a marked reduction (≈90%) in peak Na(+) current density compared with WT channels. Peak current density generated by p.D1816VfsX7+WT was ≈50% of that generated by WT channels. p.D1816VfsX7 positively shifted activation and inactivation curves, leading to a significant reduction of the window current. The mutation accelerated current activation and reactivation kinetics and increased the fraction of channels developing slow inactivation with prolonged depolarizations. However, late INa was not modified by the mutation. p.D1816VfsX7 produced a marked reduction of channel trafficking toward the membrane that was not restored by decreasing incubation temperature during cell culture or by incubation with 300 μM mexiletine and 5 mM 4-phenylbutirate.</AbstractText>Despite a severe truncation of the C-terminus, the resulting mutated channels generate currents, albeit with reduced amplitude and altered biophysical properties, confirming the key role of the C-terminal domain in the expression and function of the cardiac Na(+) channel.</AbstractText> |
12,332 | Exploring which patients without return of spontaneous circulation following ventricular fibrillation out-of-hospital cardiac arrest should be transported to hospital? | Currently many emergency medical services (EMS) that provide advanced cardiac life support (ACLS) at scene do not routinely transport out-of-hospital cardiac arrest (OHCA) patients without sustained return of spontaneous circulation (ROSC). This is due to logistical difficulties and historical poor outcomes. However, new technology for mechanical chest compression has made transport to hospital safer and extracorporeal membrane oxygenation during cardiopulmonary resuscitation (ECPR) enabling further intervention, may result in ROSC. We aimed to explore the characteristics and outcomes of patients with OHCA who were transported to hospital with ongoing CPR in the absence of ROSC, who might benefit from this new technology.</AbstractText>The Victorian Ambulance Cardiac Arrest Registry (VACAR) was searched for adult OHCA with an initial shockable rhythm between 2003 and 2012. There were 5593 OHCA meeting inclusion criteria. Analysis was performed on 3095 (55%) of patients who did not achieve sustained ROSC in the field. Of these only 589 (20%) had ongoing CPR to hospital. There was a significant decline in rates of transport over the study period. Predictors of transport with ongoing CPR included younger patients, decreased time to first shock and intermittent ROSC prior to transport. Survival to hospital discharge occurred in 52 (9%) of patients who had ongoing CPR to hospital.</AbstractText>In an EMS that provides ACLS at scene, patients without ROSC in the field who receive CPR to hospital have poor outcomes. Developing a system which provides safe transport with ongoing CPR to a hospital that provides ECPR, should be considered.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,333 | Outcomes associated with amiodarone and lidocaine in the treatment of in-hospital pediatric cardiac arrest with pulseless ventricular tachycardia or ventricular fibrillation. | To determine the association between amiodarone and lidocaine and outcomes in children with cardiac arrest with pulseless ventricular tachycardia (pVT) and ventricular fibrillation (VF).</AbstractText>Current AHA guidelines for CPR and emergency cardiovascular care recommend amiodarone for cardiac arrest in children associated with shock refractory pVT/VF, based on a single pediatric study and extrapolation from adult data.</AbstractText>Retrospective cohort study from the Get With the Guidelines-Resuscitation database for in-patient cardiac arrest. Patients<18 years old with pVT/VF cardiac arrest were included. Patients receiving amiodarone or lidocaine prior to arrest or whose initial arrest rhythm was unknown were excluded. Univariate analysis was performed to assess the association between patient and event factors and clinical outcomes. Multivariate analysis was performed to address independent association between lidocaine and amiodarone use and outcomes.</AbstractText>Of 889 patients, 171 (19%) received amiodarone, 295 (33%) received lidocaine, and 82 (10%) received both. Return of spontaneous circulation (ROSC) occurred in 484/889 (54%), 24-h survival in 342/874 (39%), and survival to hospital discharge in 194/889 (22%). Lidocaine was associated with improved ROSC (adjusted OR 2.02, 95% CI 1.36-3), and 24-h survival (adjusted OR 1.66, 95% CI 1.11-2.49), but not hospital discharge. Amiodarone use was not associated with ROSC, 24h survival, or survival to discharge.</AbstractText>For children with in-hospital pVT/VF, lidocaine use was independently associated with improved ROSC and 24-h survival. Amiodarone use was not associated with superior rates of ROSC, survival at 24h. Neither drug was associated with survival to hospital discharge.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,334 | Acute kidney injury after cardiac arrest of ventricular fibrillation and asphyxiation swine model. | The purposes of the study are to investigate the renal function in ventricular fibrillation (VF) and asphyxiation cardiac arrest in a swine model and to estimate the value of novel biomarkers in the acute kidney injury (AKI) after cardiac arrest.</AbstractText>Thirty-two healthy inbred Wu-Zhi-Shan miniature piglets were randomized into 2 groups (n = 16 per group). Cardiac arrest was induced by programmed electric stimulation and clamping the endotracheal tube in the VF group and asphyxiation group, respectively. Cardiopulmonary resuscitation was done for return of spontaneous circulation (ROSC).</AbstractText>One hundred percent (16/16) ROSC was observed in the VF group, and 50% (8/16) in the asphyxiation group (P < .01). All AKI biomarkers elevated significantly after ROSC. The novel biomarkers changed much earlier than the creatinine. The concentration of novel biomarkers in the asphyxiation group was higher than the VF group. Live animals had an oliguria and developed AKI. Characteristic morphological injuries in renal tissues were observed under light microscope and transmission electron microscope and were more serious in the asphyxiation group.</AbstractText>Acute kidney injury at early stage of postresuscitation is common in different causes of cardiac arrest. Asphyxiation has more severe kidney injury and gets worse prognosis.</AbstractText>Copyright © 2014 Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,335 | Predictors of 6-month poor clinical outcomes after transcatheter aortic valve implantation. | Patient selection for transcatheter aortic valve implantation (TAVI) remains a major concern. Indeed, despite promising results, it is still unclear which patients are most and least likely to benefit from this procedure.</AbstractText>To identify predictors of 6-month poor clinical outcomes after TAVI.</AbstractText>Patients who were discharged from our institution with a transcatheter-implanted aortic valve were followed prospectively. Our population was divided into two groups ('good outcomes' and 'poor outcomes') according to occurrence of primary endpoint (composite of all-cause mortality, all stroke, hospitalizations for valve-related symptoms or worsening heart failure from discharge to 6 months or 6-month New York Heart Association functional class III or IV). Patient characteristics were studied to find predictors of poor outcomes.</AbstractText>We included 163 patients (mean age, 79.9 ± 8.8 years; 90 men [55%]; mean logistic EuroSCORE, 18.4 ± 11.4%). The primary endpoint occurred in 49 patients (mean age, 83 ± 5 years; 31 men [63%]). By multivariable analysis, atrial fibrillation (odds ratio [OR] 3.94), systolic pulmonary artery pressure ≥60 mmHg (OR 7.56) and right ventricular dysfunction (OR 3.55) were independent predictors of poor outcomes, whereas baseline aortic regurgitation ≥2/4 (OR 0.07) demonstrated a protective effect.</AbstractText>Atrial fibrillation, severe baseline pulmonary hypertension and right ventricular dysfunction (i.e. variables suggesting a more evolved aortic stenosis) were predictors of 6-month poor outcomes. Conversely, baseline aortic regurgitation ≥2/4 showed a protective effect, which needs to be confirmed in future studies. Our study highlights the need for a specific 'TAVI risk score', which could lead to better patient selection.</AbstractText>Copyright © 2013 Elsevier Masson SAS. All rights reserved.</CopyrightInformation> |
12,336 | Prognostic usefulness of left ventricular hypertrophy by electrocardiography in patients with atrial fibrillation (from the Randomized Evaluation of Long-Term Anticoagulant Therapy Study). | It is unknown whether left ventricular hypertrophy (LVH) diagnosis by electrocardiography improves risk stratification in patients with atrial fibrillation (AF). We investigated the prognostic impact of LVH diagnosis by electrocardiography in a large sample of anticoagulated patients with AF included in the Randomized Evaluation of Long-Term Anticoagulant Therapy (RE-LY) Study. We defined electrographic LVH (ECG-LVH) by strain pattern or Cornell voltage (R wave in aVL plus S wave in V3) >2.0 mV (women) or >2.4 mV (men). LVH prevalence was 22.7%. During a median follow-up of 2.0 years, 303 patients developed a stroke, 778 died (497 from cardiovascular causes), and 140 developed a myocardial infarction. LVH was associated with a greater risk of stroke (1.99% vs 1.32% per year, hazard ratio [HR] 1.51, 95% confidence interval [CI] 1.18 to 1.93, p <0.001), cardiovascular death (4.52% vs 1.80% per year, HR 2.56, 95% CI 2.14 to 3.06, p <0.0001), all-cause death (6.03% vs 3.11% per year, HR 1.95, 95% CI 1.68 to 2.26, p <0.0001), and myocardial infarction (1.11% vs 0.55% per year, HR 2.07, 95% CI 1.47 to 2.92, p <0.0001). In multivariate analysis, the prognostic value of LVH was additive to CHA2DS2-VASc score and other covariates. The category-free net reclassification index and integrated discrimination improvement increased significantly after adding LVH to multivariate models. In conclusion, our study demonstrates for the first time that ECG-LVH, a simple and easily accessible prognostic indicator, improves risk stratification in anticoagulated patients with AF. |
12,337 | Prognostic relevance of pulmonary arterial compliance in patients with chronic heart failure. | Reduced pulmonary arterial compliance (Ca) is a marker of poor prognosis in idiopathic pulmonary arterial hypertension. We tested the hypothesis that pulmonary arterial Ca could be a predictor of outcome in patients with chronic heart failure (CHF).</AbstractText>We enrolled 306 patients with CHF due to systolic left ventricular dysfunction (sLVD) who underwent a clinically driven right-sided heart catheterization. Pulmonary arterial Ca was measured by the ratio between stroke volume and pulse pressure (SV/PP). The primary end point was cardiovascular death; secondary end point was the composite of cardiovascular death, urgent heart transplantation, and appropriately detected and treated episode of ventricular fibrillation.</AbstractText>An inverse relationship was observed between SV/PP and pulmonary vascular resistance, the mean resistance-compliance product (RC-time) being 0.30 ± 0.2 s. In patients with pulmonary capillary wedge pressure (PCWP) &lt; 15 mm Hg, the mean RC-time was 0.34 ± 0.14 s, and in patients with PCWP ≥ 15 mm Hg it was 0.28 ± 0.22 s. Eighty-seven patients died in a follow-up period of 50 ± 32 months. At receiver operating characteristic curve analysis, the optimal prognostic cutoff point of SV/PP was 2.15 mL/mm Hg. An elevated (&gt; 2.15) SV/PP was more strongly associated with survival than any other hemodynamic variable; it was associated with poor prognosis both in patients with high (P = .003) and in patients with normal pulmonary vascular resistance (P = .005).</AbstractText>Pulmonary arterial Ca is a strong prognostic indicator in patients with CHF with sLVD. Most importantly, its prognostic role is retained in patients with normal pulmonary vascular resistance.</AbstractText> |
12,338 | The previous use of digoxin does not worsen early outcome of acute coronary syndromes: an analysis of the ARIAM Registry. | The aim of the study was to determine the influence of the previous use of digoxin on the hospital mortality and complications of patients admitted because of acute coronary syndrome (ACS). We analyzed the data of patients included in the ARIAM-Andalucia Registry, which involves 49 hospitals in Andalucia, Spain, from 2007 to 2012. Patients on digoxin treatment prior to their admission because of ACS constituted the digoxin group (DG), and were compared with the group of patients not on digoxin. Logistic regression and propensity score matching were used to analyze the differences. We included 20,331 patients, of whom 244 (1.2%) were on digoxin. DG patients were older (73.1 vs 63.7 years old), more often women, and had more diabetes, hypertension, previous myocardial infarction, heart failure, stroke, atrial fibrillation, peripheral vascular disease, obstructive pulmonary disease or kidney disease. On univariate analysis, DG patients had significantly higher hospital mortality (13.5 vs 5.3% P < 0.001), and more cardiogenic shock, but less ventricular fibrillation, and no differences in atrioventricular block, stroke or reinfarction. After the multivariate analysis, DG had no significant influence on hospital prognosis [odds ratio (OR) 1.21, 95% confidence interval 0.79-1.86]. The analysis of a propensity-matched cohort of 464 patients (232 DG and 232 NoDG) did not find differences in hospital mortality (13.4 vs 13.4%) nor other complications. In our cohort of ACS patients, the previous treatment with digoxin was not associated with an increase in dysrhythmic complications nor was an independent predictor of mortality during hospitalization. |
12,339 | Cryoballoon pulmonary vein isolation prior to percutaneous atrial septal defect closure: a case report. | We report the case of a 61-year-old female who was admitted to our department with progressive dyspnea and palpitation. Transthoracic echocardiography and transesophageal echocardiography showed a small atrial septal defect (ASD, 8x7 mm). Paroxysmal atrial fibrillation (AF) was detected in Holter monitoring. As repair of ASD does not significantly reduce the risk of arrhythmias, cryoablation of AF was performed prior to ASD closure. On cardiac examination at one year, this combined intervention improved right ventricular function and prevented AF episodes. |
12,340 | Use of automated external defibrillators in US federal buildings: implementation of the Federal Occupational Health public access defibrillation program. | Federal Occupational Health (FOH) administers a nationwide public access defibrillation program in US federal buildings. We describe the use of automated external defibrillators (AEDs) in federal buildings and evaluate survival after cardiac arrest.</AbstractText>Using the FOH database, we examined reported events in which an AED was brought to a medical emergency in federal buildings over a 14-year period, from 1999 to 2012.</AbstractText>There were 132 events involving an AED, 96 (73%) of which were due to cardiac arrest of cardiac etiology. Of 54 people who were witnessed to experience a cardiac arrest and presented with ventricular fibrillation or ventricular tachycardia, 21 (39%) survived to hospital discharge.</AbstractText>Public access defibrillation, along with protocols to install, maintain, and deploy AEDs and train first responders, benefits survival after cardiac arrest in the workplace.</AbstractText> |
12,341 | Custodiol for myocardial protection and preservation: a systematic review. | Custodiol cardioplegia is attractive for minimally invasive cardiac surgery, as a single dose provides a long period of myocardial protection. Despite widespread use in Europe, there is little data confirming its efficacy compared with conventional (blood or crystalloid) cardioplegia. There is similar enthusiasm for its use in organ preservation for transplant, but also a lack of data. This systematic review aimed to assess the evidence for the efficacy of Custodiol in myocardial protection and as a preservation solution in heart transplant.</AbstractText>Electronic searches were performed of six databases from inception to October 2013. Reviewers independently identified studies that compared Custodiol with conventional cardioplegia (blood or extracellular crystalloid) in adult patients for meta-analysis; large case series that reported results using Custodiol were analyzed. Next, we identified studies that compared Custodiol with other organ preservation solutions for organ preservation in heart transplant.</AbstractText>Fourteen studies compared Custodiol with conventional cardioplegia for myocardial protection in adult cardiac surgery. No difference was identified in mortality; there was a trend for increased incidence of ventricular fibrillation in the Custodiol group that did not reach statistical significance. No difference was identified in studies that compared Custodiol with other solutions for heart transplant.</AbstractText>Despite widespread clinical use, the evidence supporting the superiority of Custodiol over other solutions for myocardial protection or organ preservation is limited. Large randomised trials are required.</AbstractText> |
12,342 | Intravenous immunoglobulin in the therapy of adult acute fulminant myocarditis: A retrospective study. | Acute fulminant myocarditis (AFM) is a serious heart disease with limited treatment. This observational retrospective study aimed to investigate whether intravenous immunoglobulin (IVIG) was able to improve left ventricular function and reduce the episodes of arrhythmia in adult patients with AFM. The medical records of all patients with AFM who were admitted to the Critical Care Unit of Guangdong General Hospital (Guangzhou, China) between January 2001 and December 2010 were reviewed. A cohort of 58 patients was included in the study. Of these 58, 32 patients were treated with IVIG (400 mg/kg per day) for five days, while the remaining patients did not receive IVIG therapy. The patients who received IVIG therapy had a higher left ventricular ejection fraction (LVEF) and a reduced left ventricular end-diastolic diameter (LVDD) compared with the non-IVIG therapy patients four weeks subsequent to the treatment (P<sub>LVEF</sub>=0.011 and P<sub>LVDD</sub>=0.048). The post-treatment incidence of ventricular tachycardia/ventricular fibrillation (VT/VF) and atrioventricular block (AVB) was reduced in the patients who received IVIG therapy compared with the baseline values (P<sub>VT/VF</sub>=0.025, P<sub>AVB</sub>=0.003); however, no significant differences were observed in the non-IVIG therapy patients (P<sub>VT/VF</sub>=0.564, P<sub>AVB</sub>=0.083) following treatment. There were two mortalities in the IVIG therapy group and seven in the non-IVIG therapy group (P=0.072). This retrospective study suggested that the use of IVIG for the treatment of AFM may be associated with improved left ventricular function and reduced episodes of fulminant arrhythmias. |
12,343 | Implantable cardioverter defibrillator and inappropriate therapy: "black box" examination yielded both human and technical causes. | We report on a 70-year-old male patient who was recipient of GEM III DR 7275 Cardioverter Defibrillator, and who presented with inappropriate shocks. The patient had a documented slow ventricular tachycardia (VT), and the device was programmed to detect VT at rates >100 bpm, fast VT (FVT, via VT) at rates >150 bpm, and ventricular fibrillation (VF) at rates >188 bpm. After detection of FVT, efficient therapy was delivered; however, this was immediately followed by multiple inappropriate therapies. Inappropriate therapies were discussed, with a focus on programming features. |
12,344 | Survival, predictive factors, and causes of mortality following transcatheter aortic valve implantation. | Transcatheter aortic valve implantation (TAVI) is considered the standard of care for patients with severe symptomatic aortic stenosis unsuitable for surgery. However, short- and long-term mortality after TAVI are still relatively high. The aim of this study was to establish survival, predictive factors, and causes of mortality after TAVI at early and midterm follow-up.</AbstractText>Between December 2007 and May 2012, a total of 119 patients with symptomatic severe aortic stenosis underwent 121 TAVI procedures. The mean ± SD age was 81 ± 9 years, and 59% were men. The mean ± SD logistic European System for Cardiac Operative Risk Evaluation was 22 ± 15. Seventy-five patients (63%) were in New York Heart Association functional class III to IV. The transfemoral approach was used in 76% of the patients. One hundred ten patients (91%) had the CoreValve prosthesis, and 11 (9%) had an Edwards SAPIEN valve. Baseline characteristics, procedural complications, and outcomes were collected prospectively. Clinical outcomes were defined according to the Valve Academic Research Consortium criteria. Follow-up was completed for 100% of the patients at a median of 1.3 years (range, 0-4.5).</AbstractText>The total number of deaths was 36 (30%). One-month mortality was 4.2%. Actuarial survival was 83.2%, 76.5%, and 68.2% at 1, 2, and 3 years, respectively. Acute kidney injury occurred in 12.3% of the patients, none of whom required dialysis during hospitalization. Twenty-one patients (17.6%) had new conduction abnormalities that required permanent pacemaker implantation before hospital discharge. The incidence of major vascular injury and stroke was 2.4% and 4.1%, respectively. Survival was significantly adversely affected by preprocedural left ventricular dysfunction (P = 0.04), history of atrial fibrillation (P = 0.03), prior heart block (P < 0.01), and critical preoperative state (P < 0.01). Twelve (33%) of the 36 deaths were due to bronchopneumonia. In 12 (33%) of the 36 patients who died, mortality was related to cardiac causes. When a death occurred within the first 30 days, it was mainly cardiac in nature (80%). Twelve patients (34%) died because of a variety of other reasons such as pulmonary embolism, stroke, cancer, renal failure, and sepsis.</AbstractText>Preprocedural left ventricular dysfunction, atrial fibrillation, and heart block are independent predictive factors of all-cause mortality. Early mortality was mainly cardiac in origin. Most of the late deaths were caused by noncardiac reasons, with bronchopneumonia being reported as the most common cause of late mortality.</AbstractText> |
12,345 | Improved cardiac and neurologic outcomes with postresuscitation infusion of cannabinoid receptor agonist WIN55, 212-2 depend on hypothermia in a rat model of cardiac arrest. | To investigate the mechanisms of improved myocardial and neurological function and survival following i.v. administration of cannabinoid receptor agonist, WIN55, 212-2 in a rat model of cardiac arrest.</AbstractText>Prospective randomized controlled experimental study.</AbstractText>University-affiliated research institute.</AbstractText>Thirty male Sprague-Dawley rats.</AbstractText>Ventricular fibrillation was electrically induced in 30 male Sprague-Dawley rats weighing between 450 and 550 g. Cardiopulmonary resuscitation was initiated after 6 minutes of untreated ventricular fibrillation. The precordial compression was performed with a pneumatically driven mechanical chest compressor. No pharmacological agent was used during cardiopulmonary resuscitation. After 8 minutes of cardiopulmonary resuscitation, up to three 2-J defibrillations were attempted. The animals were then randomized into three groups: 1) WIN55, 212-2 hypothermia, 2) WIN55, 212-2 with normal body temperature, and 3) placebo control. Either WIN55, 212-2 (1.0 mg/kg/hr) or saline placebo was continuously infused for 2 hours. Except for the WIN55, 212-2 hypothermia group, the body temperature in the other two groups was maintained at 37.0 ± 0.2°C using an external heating lamp. Postresuscitation myocardial function was measured by echocardiogram. Neurological deficit scores and survival time were observed for up to 72 hours.</AbstractText>Blood temperatures decreased from 37°C to 33°C in 4 hours in animals in WIN55, 212-2 hypothermia group. Myocardial function, as measured by cardiac output, ejection fraction, and myocardial performance index, was significantly impaired in all animals after successful resuscitation when compared with the baseline values. There was a significant improvement in myocardial function in the animals treated with WIN55, 212-2 hypothermia beginning at 1 hour after start of infusion. However, no improvement was observed in the groups of WIN55, 212-2 with normal body temperature and placebo control. WIN55, 212-2 hypothermia group was associated with significantly improved neurologic deficit scores and survival time when compared with placebo control group and WIN55, 212-2 with normal body temperature group.</AbstractText>In a rat model of cardiac arrest, better postresuscitation myocardial function, neurological deficit scores, and longer duration of survival were observed by the pharmacologically induced hypothermia with WIN55, 212-2. The improved outcomes of cardiopulmonary resuscitation following administration of WIN55, 212-2 appeared to be the results from its temperature reduction effects.</AbstractText> |
12,346 | Update on cardiometabolic health effects of ω-3 fatty acids. | The fish fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may promote cardiometabolic health. This review summarizes the results of recent meta-analyses of prospective studies on cardiovascular diseases, diabetes type 2 and markers of atherosclerosis and thrombosis.</AbstractText>The results of recently published meta-analyses of prospective cohort studies showed that eating fish once a week was associated with a 16% lower risk of fatal coronary heart disease (CHD) and a 14% lower risk of stroke incidence, but was not related to heart failure. Fish consumption may be associated with a higher risk of diabetes in Western countries and a lower risk in Asian countries. Recent meta-analyses of randomized controlled trials showed that EPA-DHA supplementation reduced the risk of fatal CHD and sudden death by 10% of which the latter was not significant. Extra EPA-DHA did not reduce the risk of heart failure, stroke and cardiac arrhythmias. ω-3 fatty acid (FA) supplementation did reduce markers of ventricular fibrillation, inflammation and endothelial dysfunction and platelet aggregation.</AbstractText>There is strong evidence for a protective effect of ω-3 FA on fatal CHD and for some markers of atherosclerosis and thrombosis. Consistent results were not obtained for other vascular diseases and diabetes. ω-3 FA reduced markers of ventricular fibrillation but did not reduce the risk of atrial fibrillation.</AbstractText> |
12,347 | Minimally invasive redo mitral valve surgery without aortic crossclamp. | Reoperations of the mitral valve have a higher rate of complications when compared with the first surgery. With the field of video-assisted techniques for the first surgery of mitral valve became routine, reoperation cases began to arouse interest for this less invasive procedures.</AbstractText>To assess the results and the technical difficulties in 10 patients undergoing minimally invasive redo mitral valve surgery.</AbstractText>Cardiopulmonary bypass was installed through a cannula placed in the femoral vessels and right internal jugular vein, conducted in 28 degrees of temperature in ventricular fibrillation. A right lateral thoracotomy with 5 to 6 cm in the third or fourth intercostal space was done, pericardium was displaced only at the point of atriotomy. The aorta was not clamped.</AbstractText>Ten patients with mean age of 56.9 ± 10.5 years, four were in atrial fibrilation rhythm and six in sinusal. Average time between first operation and reoperations was 11 ± 3.43 years. The mean EuroSCORE group was 8.3 ± 1.82. The mean ventricular fibrillation and cardiopulmonary bypass was respectively 70.9 ± 17.66 min and 109.4 ± 25.37 min. The average length of stay was 7.6 ± 1.5 days. There were no deaths in this series.</AbstractText>Mitral valve reoperation can be performed through less invasive techniques with good immediate results, low morbidity and mortality. However, this type of surgery requires a longer duration of cardiopulmonary bypass, especially in cases where the patient already has prosthesis. The presence of a minimal aortic insufficiency also makes this procedure technically more challenging.</AbstractText> |
12,348 | Aliskiren ameliorates sympathetic nerve sprouting and suppresses the inducibility of ventricular tachyarrhythmia in postinfarcted rat heart. | Aliskiren is an oral renin inhibitor, which inhibits the first rate limiting step in the renin angiotensin aldosterone system. In this study, sympathetic nerve sprouting and the inducibility of ventricular fibrillation after aliskiren treatment in myocardial infarction were investigated.</AbstractText>Male Sprague Dawley rats after coronary artery ligation were randomly allocated to four groups: angiotensin converting enzyme inhibitor enalapril, angiotensin receptor blocker valsartan, β adrenergic receptor blocker carvedilol and rennin inhibitor aliskiren treatment for six weeks. Electrophysiological study, histological examination and Western blotting were performed.</AbstractText>The plasma norepinephrine level and sympathetic nerve innervation significantly increased in treated infarcted rats compared to untreated rats. Aliskiren treatment reduced the sympathetic nerve innervations after myocardial infarction. There is no significant difference in sympathetic nerve innervations after myocardial infarction among the enalapril, valsartan, carvediloand or aliskiren treated groups. Programmed electrical stimulation study showed that inducible ventricular arrhythmia was reduced, ventricular fibrillation threshold was increased and ventricular effective refractory period was prolonged in enalapril, valsartan, carvedilol and aliskiren treated infarcted rats compared to untreated infarcted rats. Cardiomyocytic apoptosis in infarcted region was significantly decreased in enalapril, valsartan, carvedilol and aliskiren treated infarcted rats.</AbstractText>Aliskiren ameliorated cardiomyocytic apoptosis, attenuated the sympathetic nerve innervations and reduced the vulnerability of ventricular arrhythmias after myocardial infarction. Enalapril, valsartan and carvedilol have similar effects as aliskiren on cardiomyocytic apoptosis, sympathetic nerve innervations and vulnerability of ventricular arrhythmias after myocardial infarction.</AbstractText> |
12,349 | Polymorphisms of angiotensin-converting enzyme 2 gene confer a risk to lone atrial fibrillation in Chinese male patients. | Growing epidemiologic evidence has indicated that genetics can predispose individuals to the occurrence of lone atrial fibrillation (AF). The angiotensin-converting enzyme 2 (ACE2) gene has been established to be associated with hypertension and left ventricular hypertrophy. The objective of our study was to investigate the association of ACE2 gene polymorphisms with lone AF.</AbstractText>A total of 265 consecutive lone AF patients and 289 healthy controls were successfully investigated. The polymorphisms rs2106809 and rs2285666 were genotyped by polymerase chain reaction (PCR) and direct sequencing. A Logistic regression model was used to determine the odds ratio (OR) and 95% confidence intervals (CI) of variations of ACE2 for lone AF.</AbstractText>The T allele of rs2106809 conferred an increased risk for lone AF (OR 1.24, 95% CI 1.01-1.52, P = 0.03) in males after adjustment for conventional risk factors. SNP at rs2285666 in males was not significantly different between AF patients and controls. No association was found between the two polymorphisms in the female population with lone AF. After (36.3 ± 4.5) months of follow-up, the end point data were obtained: death (cardiac and noncardiac), ischemic stroke, and heart failure. In the male subgroup, the associations between rs2106809 T male carriers and combined end points including ischemic stroke, heart failure, and death in our study were of significance (OR 3.6, 95% CI 1.0-13.1, P = 0.04).</AbstractText>The results indicate that polymorphism at ACE2 gene is associated with male lone AF in a Chinese Han population. Lone AF males who carry the rs2106809 T allele are associated with adverse cardiac events.</AbstractText> |
12,350 | Effects of early amiodarone administration during and immediately after cardiopulmonary resuscitation in a swine model. | Aim of this experimental study was to compare haemodynamic effects and outcome with early administration of amiodarone and adrenaline vs. adrenaline alone in pigs with prolonged ventricular fibrillation (VF).</AbstractText>After 8 min of untreated VF arrest, bolus doses were administered of adrenaline (0.02 mg/kg) and either amiodarone (5 mg/kg) or saline (n = 8 per group) after randomisation. Cardiopulmonary resuscitation (CPR) was commenced immediately after drug administration, and defibrillation was attempted 2 min later. CPR was resumed for another 2 min after each defibrillation attempt, and the same dose of adrenaline was given every 4th minute during CPR. Haemodynamic monitoring and mechanical ventilation continued for 6 h after return of spontaneous circulation (ROSC), and the pigs were euthanised at 48 h. Researchers were blinded for drug groups throughout the study.</AbstractText>There was no difference in rates of ROSC and 48-h survival with amiodarone vs. saline (5/8 vs. 7/8 and 0/8 vs. 3/8, respectively). Diastolic aortic pressure and coronary perfusion pressure were significantly lower with amiodarone during CPR and 1 min after ROSC (P < 0.05). The number of electric shocks required for terminating VF, time to ROSC and adrenaline dose were significantly higher with amiodarone (P < 0.01). The incidence of post-resuscitation tachyarrhythmias tended to be higher in the saline group (P = 0.081).</AbstractText>Early administration of amiodarone did not improve ROSC or 48-h survival rates, and was associated with worse haemodynamics in this swine model of cardiac arrest.</AbstractText>© 2013 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.</CopyrightInformation> |
12,351 | The prognostic implications of lack of palpitations in patients hospitalised with atrial fibrillation: observations from a 20-year registry. | It is well recognised that patients differ in the clinical presentation of atrial fibrillation (AF), ranging from the typical symptom of palpitations, atypical symptoms in others and a substantial that are asymptomatic. Whether the different patterns of presentation are associated with differences in outcomes is not known. The aim of this study was to evaluate the prevalence and the prognostic implications of lack of palpitations among patients hospitalised with AF in a large prospective registry.</AbstractText>Retrospective analysis of all patients hospitalised with AF in Qatar from 1991 to 2010 was made. Patients were divided into two groups according to the presence or absence of palpitations on presentation. Clinical characteristics and outcome were analysed.</AbstractText>During the 20-year period, 3850 patients were hospitalised for AF; 1724 (44.8%) had palpitations on presentation while 2126 (55.2%) had no palpitations. Patients who lacked palpitations were 9 years older, had a higher prevalence of diabetes mellitus (64.7% vs. 35.3%), underlying coronary artery disease (CAD; 14.6% vs. 6.2%) and severe left ventricular dysfunction on echocardiography (25.5% vs. 6.6%), (all, p = 0.001). There were 141 deaths among the group with no palpitations compared with 19 among the group with palpitations (6.6% vs. 1.1%). Multivariate analysis of mortality predictors identified 'lack of palpitations' as an independent predictor of in-hospital mortality (relative risk 5.56; 95% confidence interval 1.20-25.0, p = 0.03).</AbstractText>Our study demonstrates for the first time that lack of palpitations as the presenting symptom of patients with AF is associated with worse in-hospital outcome independent of other risk factors or therapy. The underlying mechanisms and the role of confounders warrant further investigation.</AbstractText>© 2013 John Wiley & Sons Ltd.</CopyrightInformation> |
12,352 | Clinical and therapeutic aspects of amiodarone induced thyroid dysfunction. | Discovered in 1961 by Tondeur and Binon, two Belgian chemists, amiodarone was widely used, especially in Europe, initially as an antianginal agent, and later as an antiarrhythmic one (following the experiments conducted at the University of Oxford by Dr. Bramah Singh). Thus, the role of amiodarone was reconsidered, becoming, together with Sotalol, a class III antiarrhythmic--a group characterized by the action of extending the potassium channels refractory period. In time, amiodarone has proven its effectiveness in the treatment of both atrial and potentially malignant ventricular arrhythmias, being considered one of the antiarrhythmic agents involved in the prevention of sudden cardiac death due to arrhythmias. In December 1985, amiodarone was approved by the FDA (Food and Drug Administration) for the treatment of atrial fibrillation and the prevention of recurrent ventricular tachycardias. Despite this positive effect, the prescription of amiodarone began to be limited because serious side effects occurred, some of them disastrous, which were associated with the chronic use of the substance. |
12,353 | The importance of avoiding unnecessary right ventricular pacing in clinical practice. | Symptomatic bradycardia is effectively treated with the implantation of a cardiac pacemaker. Although a highly successful therapy, during recent years there has been a focus on the negative effects associated with long-term pacing of the apex of the right ventricle (RV). It has been shown in both experimental and clinical studies that RV pacing leads to ventricular dyssynchrony, similar to that of left bundle branch block, with subsequent detrimental effects on cardiac structure and function, and in some cases adverse clinical outcomes such as atrial fibrillation, heart failure and death. There is substantial evidence that patients with reduced left ventricular function (LVEF) are at particular high risk of suffering the detrimental clinical effects of long-term RV pacing. The evidence is, however, incomplete, coming largely from subanalyses of pacemaker and implantable cardiac defibrillator studies. In this group of patients with reduced LVEF and an expected high amount of RV pacing, biventricular pacing (cardiac resynchronization therapy) devices can prevent the negative effects of RV pacing and reduce ventricular dyssynchrony. Therefore, cardiac resynchronization therapy has emerged as an attractive option with promising results and more clinical studies are underway. Furthermore, specific pacemaker algorithms, which minimize RV pacing, can also reduce the negative effects of RV stimulation on cardiac function and may prevent clinical deterioration. |
12,354 | Predictive value of atrial electromechanical delay for atrial fibrillation recurrence. | We investigated the predictive value of atrial electromechanical delay (AEMD) for recurrence of atrial fibrillation (AF) at 1-month after cardioversion.</AbstractText>Seventy-seven patients with persistent AF were evaluated and finally 50 patients (12 men, 38 women) were included. All patients underwent transthoracic electrical DC cardioversion under amiodarone treatment. AEMD was measured as the time interval from the onset of the P wave on electrogram (ECG) to the beginning of late diastolic wave (Am) from the ventricular annulus and atrial walls on tissue Doppler imaging, in the apical 4-chamber view 24 h after cardiversion. P wave maximum-duration (Pmax), P wave minimum-duration (Pmin) and P wave dispersion-duration (Pdis) were calculated on the 12-lead ECG at 24-h postcardioversion. We followed the heart rate and rhythm by 12-lead ECG at 24-h, 1-week and 1-month.</AbstractText>At 1-month follow-up after cardioversion, 28 (56%) patients were in sinus rhythm (SR), whereas 22 (44%) patients reverted to AF. The AEMD durations were longer in AF group than SR group (p < 0.001) and were signifi cantly correlated with Pmax and Pdis (p < 0.001 for both). For AF recurrence; duration of AF, left atrial (LA) diameter, maximum LA volume index, mitral A velocity and LA lateral AEMD were significant parameters in univariate-analysis, however LA lateral AEMD was the only significant parameter in multivariate-analysis (OR: 1.46; 95% CI 1.02-2.11; p = 0.03).</AbstractText>Our results suggest that AEMD is associated with an increased risk of recurrence of AF within 1-month. These data may have implications for the identification of patients who are most likely to experience substantial benefit from cardiversion therapy for AF.</AbstractText> |
12,355 | Is abnormal myocardial repolarization associated with the occurrence of malignant tachyarrhythmias in Takotsubo cardiomyopathy? | Abnormalities of cardiac repolarization are a hallmark of Takotsubo cardiomyopathy (TC), but their association with the occurrence of syncope and ventricular tachyarrhythmias is unknown. This study sought to assess the relationship between myocardial repolarization and malignant tachyarrhythmias in TC.</AbstractText>Clinical data and electrocardiographic repolarization parameters of 28 patients with TC and ventricular tachyarrhythmias (n = 26) or syncope (n = 2) were compared to data from 20 randomly selected patients with TC but without ventricular tachyarrhythmias or syncope.</AbstractText>Study patients had significantly lower ejection fraction (EF) compared with controls (35 ± 14% vs. 46 ± 10%, p = 0.006). On day 1, no significant differences in repolarization parameters were observed. However, in the subgroup with ventricular fi brillation ([VF]; n = 10), Tpeak-Tend in lead V6 was significantly prolonged (97 ± 20 vs. 85 ± 19 ms; p = 0.04). Similarly, in the subgroup with torsade de pointes ([TdP]; n = 5) Tpeak-Tend in lead V4 was prolonged (127 ± 21 vs. 94 ± 27 ms; p = 0.001). On day 3, Tpeak-Tend in lead V3 (130 ± 51 vs. 105 ± 21 ms, p = 0.049) and Tpeak-Tend dispersion (56 ± 33 vs. 36 ± 21 ms; p = 0.03) were significantly longer in study patients. The difference in Tpeak-Tend in lead V3 was borderline in the VF subgroup, but significant in the subgroup with TdP. The latter group had also longer Tpeak-Tend in lead V4 and longer corrected QT interval in leads V3 and V4.</AbstractText>Patients with TC who experience malignant tachyarrhythmias have lower EF and a more pronounced alteration of the spatial dispersion of ventricular repolarization.</AbstractText> |
12,356 | Mechanical ventilation in the early phase of ST elevation myocardial infarction treated with mechanical revascularization. | So far, few data have been available on the incidence and outcome of patients with acute myocardial infarction (MI) requiring mechanical ventilation (MV). The aim of the study was to assess the clinical and prognostic impact of MV at short and long term in 106 patients with ST elevation MI (STEMI) requiring mechanical ventilation.</AbstractText>The incidence of mechanical ventilation was 7.6%. Reasons for intubation were as follows: cardiogenic shock in 64 (60.4%) patients, ventricular fibrillation in 32 (30.1%) patients and acute pulmonary edema in 10 (9.5%) patients. Patients submitted to MV were older (p = 0.016), more frequently had a previous percutaneous coronary intervention (PCI;p = 0.014) and a previous MI (p = 0.001). A higher in-Intensive Cardiac Care Unit death was observed in MV patients (44.3% vs. 1.5%, p < 0.001), as well as a higher mortality at follow-up (36.7% vs. 14.8%, p < 0.001). MV was associated with higher mortality rates both at short and long term.</AbstractText>In a large series of consecutive STEMI patients submitted to MV, the need of MV is a strong prognostic indicator of mortality both at short and long term. Among mechanically ventilated STEMI patients infarct size (as inferred by TnI values) and PCI failure were independent predictors of early death, while the duration of MV was related to death at longterm.</AbstractText> |
12,357 | Clinical implications of left ventricular assist device implantation in patients with an implantable cardioverter-defibrillator. | This study aims to study the clinical implications of the concomitant use of a left ventricular assist device (LVAD) and an implantable cardioverter-defibrillator (ICD).</AbstractText>In this retrospective study, all patients who underwent LVAD (Heart Mate II) implantation with concomitant ICD therapy at our institution between June 2007 and August 2012 were included. We sought to investigate (1) the electromagnetic interference between LVAD and ICD telemetry, (2) the effect of LVAD implantation on right ventricular (RV) lead parameters and (3) the ventricular tachyarrhythmias (VAs) that occur post-LVAD implantation.</AbstractText>Of the 23 patients (53 ± 9 years, 73 % male, LVEF 19 ± 9 %) included, ICD telemetry was lost in four patients post-LVAD implantation (Saint-Jude-Medical Atlas V-193, V-240, V-243, and Sorin CRT-8750), prompting either use of a metal shield (n = 1), a change in position of the programmer head (n = 1) or ICD replacement (n = 2). LVAD implantation was associated with a decrease in both RV signal amplitude (p = 0.04) and RV impedance (p < 0.01), and a trend towards an increased RV pacing threshold (p = 0.08), without affecting clinical outcome. Eleven patients (47.8 %) experienced VAs after LVAD implantation, which on the whole were well tolerated. Their occurrence was strongly linked to a history of VAs before device implantation (p < 0.01).</AbstractText>Electromagnetic interference between LVADs and ICD telemetry may necessitate ICD replacement. LVAD placement is associated with significant changes in RV lead parameters that have minimal clinical significance. VAs occur in approximately half of LVAD patients seen and their occurrence is strongly related to a history of VAs prior to LVAD implantation.</AbstractText> |
12,358 | The importance of non-uniformities in mechano-electric coupling for ventricular arrhythmias. | Cardiac mechanical and electrical activities are tightly linked through an intra-cardiac regulatory loop (mechano-electric coupling). This connection is essential for normal heart function and auto-regulation. In diseases associated with altered myocardial mechanical properties or function, however, feedback from the mechanical environment to the origin and spread of excitation can result in deadly cardiac arrhythmias. Ventricular tachyarrhythmias, especially, are encountered in cardiac diseases associated with volume and pressure overload or changes in tissue mechanics. Little is known about the influence of changes in mechano-electric coupling on cardiac rhythm in these settings or the potential therapeutic benefit of its manipulation. Improved understanding may be central to explaining the origin of arrhythmias that occur with these pathologies and to the development of novel mechanics-based therapies. The present review explores the potential role of mechano-electric coupling in ventricular arrhythmogenesis, with a focus on the importance of non-uniformity in mechanical function for the induction and sustenance of ventricular tachyarrhythmias. |
12,359 | Surgical myectomy improves pulmonary hypertension in obstructive hypertrophic cardiomyopathy. | Characterization of pulmonary hypertension (PH) and the effects of myectomy in hypertrophic cardiomyopathy (HCM) remain poorly defined. The aim of the study was to investigate the effect of myectomy on PH in HCM.</AbstractText>This is a retrospective analysis of 306 consecutive symptomatic HCM patients (70% NYHA class III-IV) with evaluation of echocardiographic right ventricular systolic pressure (RVSP) both preceding (median 3 days) and following (median 4 days) myectomy. Compared with patients without PH (RVSP <35 mmHg, n = 145, 47%), patients with moderate or severe PH (RVSP ≥50 mmHg, n = 51, 17%) were older, predominantly female, had a greater prevalence of atrial fibrillation, higher natriuretic peptide levels, higher left ventricular outflow tract gradient, higher E velocity, and larger left atria. Reduction of RVSP post-myectomy was evident in patients with moderate or severe PH [59 (IQR 54-71) to 50 (IQR 39-62) mmHg, P < 0.0001] and in all patients with PH [RVSP ≥ 35 mmHg, n = 161, 43 (IQR 39-54) to 41 (IQR 35-52) mmHg, P < 0.0001]. In a subgroup of patients with long-term data, PH continued to decline during follow-up. Clinical variables associated with improvement in PH in these patients were higher left atrial volume index (R = 0.43, P = 0.0069) and moderate or severe mitral regurgitation (R = 0.33, P = 0.038).</AbstractText>Surgical myectomy is associated with improvement in PH, most pronounced in moderate or severe PH. These data provide insight into pulmonary haemodynamics following obstruction relief and can help to guide therapeutic expectations.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2013. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
12,360 | Right ventricular apical pacing-induced left ventricular dyssynchrony is associated with a subsequent decline in ejection fraction. | In patients with normal left ventricular (LV) ejection fraction (EF), the interposition of chronic, high-dose right ventricular apical (RVA) pacing may produce late EF decline.</AbstractText>To test the hypothesis that LV dyssynchrony, defined echocardiographically and apparent early after interposition of pacing, would be greater in patients who subsequently demonstrated EF decline.</AbstractText>Ninety-one patients with normal prepacing EF who underwent atrioventricular node ablation and subsequent high-dose RVA pacing were studied. Transthoracic echocardiograms were performed early (median 4 months) and late (median 28 months) after interposition of pacing, with a significant decline in EF between these studies defined as ≥5%. Speckle-tracking longitudinal strain analysis of the early echocardiogram was performed to quantify dyssynchrony. In addition to standard dyssynchrony indices, a novel index of apex-to-base mechanical propagation delay (MPD) was used.</AbstractText>Multivariable analysis determined that MPD of the septum correlated with a significant decline in EF, independent of all other dyssynchrony, clinical, or pacing variables. A septal MPD value exceeding 50 ms was associated with EF decline at 81% sensitivity and 88% specificity.</AbstractText>Dyssynchrony, in particular septal MPD, measured early after interposition of high-dose RVA pacing predicted a significant late decline in EF in patients who had normal prepacing EF.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,361 | Patients treated with catheter ablation for ventricular tachycardia after an ICD shock have lower long-term rates of death and heart failure hospitalization than do patients treated with medical management only. | Ventricular arrhythmias in patients with implantable cardioverter-defibrillators (ICDs) adversely affect outcomes. Antiarrhythmic approaches to ventricular tachycardia (VT) have variable efficacy and may increase risk of ventricular arrhythmias, worsening cardiomyopathy, and death. Comparatively, VT ablation is an alternative approach that may favorably affect outcomes.</AbstractText>To further explore the effect on long-term outcomes after catheter ablation of VT, we compared patients with history of ICD shocks who did not undergo ablation, patients with a history of ICD shocks that underwent ablation, and patients with ICDs who had no history of ICD shocks.</AbstractText>A total of 102 consecutive patients with structural heart disease who underwent VT ablation for recurrent ICD shocks were compared with 2088 patients with ICDs and no history of appropriate shocks and 817 patients with ICDs and a history of appropriate shocks for VT or ventricular fibrillation. Outcomes considered were mortality, heart failure hospitalization, atrial fibrillation, and stroke/transient ischemic attack.</AbstractText>The mean age of 3007 patients was 65.4 ± 13.9 years. Over long-term follow-up, 866 (28.8%) died, 681 (22.7%) had a heart failure admission, 706 (23.5%) developed new-onset atrial fibrillation, and 224 (7.5%) had a stroke. The multivariate-adjusted risks of deaths and heart failure hospitalizations were higher in patients with history of ICD shocks who were treated medically than in patients with ICDs and no history of shock (hazard ratio [HR] 1.45; P < .0001 vs HR 2.00; P < .0001, respectively). The multivariate-adjusted risks were attenuated after VT ablation with death and heart failure hospitalization rates similar to those of patients with no shock (HR 0.89; P = .58 vs HR 1.38; P = .09, respectively). A similar nonsignificant trend was seen with stroke/transient ischemic attack.</AbstractText>Patients treated with VT ablation after an ICD shock have a significantly lower risk of death and heart failure hospitalization than did patients managed medically only. The adverse event rates after VT ablation were similar to those of patients with ICDs but without VT.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,362 | J wave elevation to monitor quinidine efficacy in early repolarization syndrome. | We present the case of a 14-year-old female with early repolarization syndrome who presented with recurrent ventricular fibrillation and ICD shocks which were refractory to multiple drugs and catheter ablation. Treatment with quinidine, an Ito blocker, resulted in a normalization of J waves and suppression of VF. Interestingly, J wave amplitude correlated with the ventricular arrhythmia susceptibility and quinidine levels. The case highlights the importance of quinidine for management of ventricular arrhythmias in the context of early repolarisation and suggests that J wave amplitude may be an important indicator of therapeutic drug levels and arrhythmia susceptibility. |
12,363 | Fate of functional tricuspid regurgitation in aortic stenosis after aortic valve replacement. | Functional tricuspid regurgitation (TR) is found not infrequently in conjunction with aortic stenosis. The aim of the present study was to evaluate the changes in TR and to identify the predictors of late progression after aortic valve replacement.</AbstractText>We evaluated 354 patients who had undergone aortic valve replacement for aortic stenosis from January 1995 to December 2009. Patients with mitral regurgitation were excluded. Of the 354 patients, 54 had TR greater than mild. The mean follow-up duration was 4.4±4.3 years (maximum, 15). The serial echocardiographic and clinical data were analyzed.</AbstractText>No early mortality occurred, and the late cardiac mortality rate was 3.9% (14 of 354). In the 48 patients with TR greater than mild, TR did not improve in 23 (49.1%) during the follow-up period. Freedom from cardiac mortality at 10 years was lower in those with TR greater than mild than in patients without TR (61.6%±16.7% vs 93.0%±2.9%, P=.008). Left ventricular diastolic function correlated with right ventricular systolic pressure (P<.001) and the degree of TR during follow-up (P=.001). Multivariate analysis showed that postoperative atrial fibrillation (odds ratio, 6.8; P=.001) and the aortic transprosthetic mean pressure gradient (odds ratio, 1.1; P=.028) predicted late TR greater than mild.</AbstractText>Not only did TR in patients with aortic stenosis frequently persist after aortic valve replacement, it was progressive in some. This finding was associated with left ventricular diastolic dysfunction. A concomitant tricuspid valve procedure could be considered in selected patients with aortic stenosis to avoid late TR.</AbstractText>Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,364 | [Effects of noninvasive positive pressure ventilation on patients with arrhythmia complicated by sleep apnea syndrome]. | To investigate the clinical efficacy of noninvasive positive pressure ventilation (NPPV) in treatment of patients with arrhythmia complicated by sleep apnea syndrome (SAS).</AbstractText>One hundred and thirty-five arrhythmia patients with polysomnography diagnosed SAS were randomly divided into NPPV group (69 cases) and control group (66 cases), the NPPV group was treated with standard medications and NPPV, and the control group was treated with standard medications. SAS related parameters were compared between the groups after 3 months therapy.</AbstractText>(1) Epworth sleepiness scale (ESS) score, apnea-hypopnea index (AHI) and arousal index were significantly lower (8.25 ± 5.41 vs.4.08 ± 3.43, 39.95 ± 7.32 vs. 4.71 ± 1.80 and 39.69 ± 4.40 vs. 15.20 ± 2.05, P < 0.01) while not rapid eye movement (NREM) III and rapid eye movement stage of sleep time and lowest pulse oxygen saturation (LSaO2) were significantly higher in NPPV group than in control group [(4.53 ± 2.10)% vs. (16.78 ± 2.59)%,(8.37 ± 1.380)% vs. (15.25 ± 1.41)%, (77.15 ± 6.72)% vs. (93.35 ± 2.03)%, P < 0.01] after 3 months therapy. (2) Incidence of Sinus bradycardia, sinus tachycardia, sinus arrest, atrial premature beats, ventricular premature beats, paroxysmal atrial tachycardia, paroxysmal ventricular tachycardia, atrial fibrillation, II-III degree atrioventricular block, ST-T segment changes were reduced from 57.4%, 44.4%, 7.4%, 20.4%, 13.0%, 36.5%, 12.0%, 8.3%, 37.0%, 53.7% to 4.6%, 1.9%,0.0%, 3.7%, 2.8%, 7.0%, 0.9%, 0.0%, 1.9%, 4.6% (all P < 0.05) and the total number of arrhythmias happened at night were significantly lower (all P < 0.05) while the heart rate variability (HRV) were significantly higher (P < 0.01) in NPPV group than in control group; AHI was positively while LSaO2 was negatively correlated with the total night arrhythmia number (P < 0.01).</AbstractText>Noninvasive positive pressure ventilation is an effective therapy strategy for treating patients with arrhythmia complicated by sleep apnea syndrome.</AbstractText> |
12,365 | [Important changes in the Dutch College of General Practitioners (NHG) practice guideline 'Atrial fibrillation': revised practice guideline issued]. | A small number of points in the NHG practice guideline 'Atrial fibrillation' have been reviewed; this has important consequences for general practice. The risk of ischaemic CVA in patients with atrial fibrillation is determined using a new risk score (CHA2DS2-VASc). The target value of the resting ventricular frequency has been increased from a maximum of 90 to a maximum of 110 beats per minute. Oral anticoagulants are indicated in almost all patients aged 65 years and older with atrial fibrillation; the only group in whom antithrombotic medication is not indicated is men under the age of 75 with no cardiovascular comorbidity. Acetylsalicylic acid for the prevention of thrombo-embolism is only indicated if oral anticoagulants are contra-indicated. The new oral anticoagulants (NOACs) have very limited use in the prevention of a thrombo-embolism in general practice. |
12,366 | VLCAD deficiency in a patient who recovered from ventricular fibrillation, but died suddenly of a respiratory syncytial virus infection. | VLCAD deficiency is an autosomal recessive disorder caused by a defect of fatty acid oxidation. The phenotype is classified into three clinical forms on the basis of the onset of symptoms: a severe form with neonatal onset; a milder form with childhood onset; and a late-onset form. The neonatal form is the most common, and has a higher mortality rate than the others. We report the case of a newborn infant with VLCAD deficiency who developed ventricular fibrillation, which was successfully treated by intensive care, but who suddenly died after a respiratory syncytial virus infection. Early institution of i.v. glucose treatment and active immunization with vaccine, such as palivizumab (anti-RSV mAb), may be important to reduce the frequency and severity of life-threatening episodes. |
12,367 | Inefficacy of a highly selective T-type calcium channel blocker in preventing atrial fibrillation related remodeling. | The T-type Ca(2+) channel (I(CaT)) blocker mibefradil prevents AF-promoting remodeling occurring with atrial tachycardia, an action that has been attributed to I(CaT) inhibition. However, mibefradil has other effects, including ability to inhibit L-type Ca(2+) channels, Na(+) channels and cytochromes. Thus, the relationship between I(CaT) inhibition and remodeling protection in AF is still unknown.</AbstractText>To assess the effects of a novel highly selective Cav3 (I(CaT)) blocker, AZ9112, on atrial remodeling induced by 1-week atrial tachypacing (AT-P) in dogs.</AbstractText>Mongrel dogs were subjected to AT-P at 400 bpm for 7 days, with atrioventricular-node ablation and right-ventricular demand pacing (80 bpm) to control ventricular rate. Four groups of dogs were studied in investigator-blinded fashion: (1) a sham group, instrumented but without tachypacing or drug therapy (n = 5); (2) a placebo group, tachypaced but receiving placebo (n = 6); (3) a positive control tachypacing group receiving mibefradil (n = 6); and (4) a test drug group, subjected to tachypacing during oral treatment with AZ9112 (n = 8).</AbstractText>One-week AT-P decreased atrial effective refractory period (ERP) at 6 of 8 sites and diminished rate-dependent atrial ERP abbreviation. Mibefradil eliminated AT-P-induced ERP-abbreviation at 4 of these 6 sites, while AZ9112 failed to affect ERP at any. Neither drug significantly affected AF vulnerability or AF duration.</AbstractText>I(CaT) blockade with the highly selective compound AZ9112 failed to prevent rate-related atrial remodeling. Thus, prevention of atrial electrophysiological remodeling by mibefradil cannot be attributed exclusively to I(CaT) blockade. These results indicate that I(CaT) inhibition is not likely to be a useful approach for AF therapy.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
12,368 | An evolving story of angiotensin-II-forming pathways in rodents and humans. | Lessons learned from the characterization of the biological roles of Ang-(1-7) [angiotensin-(1-7)] in opposing the vasoconstrictor, proliferative and prothrombotic actions of AngII (angiotensin II) created an underpinning for a more comprehensive exploration of the multiple pathways by which the RAS (renin-angiotensin system) of blood and tissues regulates homoeostasis and its altered state in disease processes. The present review summarizes the progress that has been made in the novel exploration of intermediate shorter forms of angiotensinogen through the characterization of the expression and functions of the dodecapeptide Ang-(1-12) [angiotensin-(1-12)] in the cardiac production of AngII. The studies reveal significant differences in humans compared with rodents regarding the enzymatic pathway by which Ang-(1-12) undergoes metabolism. Highlights of the research include the demonstration of chymase-directed formation of AngII from Ang-(1-12) in human left atrial myocytes and left ventricular tissue, the presence of robust expression of Ang-(1-12) and chymase in the atrial appendage of subjects with resistant atrial fibrillation, and the preliminary observation of significantly higher Ang-(1-12) expression in human left atrial appendages. |
12,369 | Using dominant eigenvalue analysis to predict formation of alternans in the heart. | Ventricular fibrillation at the whole heart level is often preceded by the alternation of action potential duration (APD), i.e., alternans, at the cellular level. As proven in many experiments, traditional approaches based on the slope of the restitution curve have not been successful in predicting alternans formation. Recently, a technique has been theoretically developed based on dominant eigenvalue analysis to predict alternans formation in isolated cardiac myocytes. Here, we aimed to demonstrate that this technique can be applied to predict alternans formation at the whole heart level. Optical mapping was performed in Langendorff-perfused hearts from New Zealand white rabbits (n = 4), which were paced at decreasing basic cycle lengths to introduce APD alternans. In each heart, the basic cycle length corresponding to the local onset of alternans, B(onset), was determined and two regions of the heart were identified at B(onset): one region which exhibited alternans (1:1(alt)) and one which did not (1:1). Corresponding two-dimensional eigenvalue (λ) maps were generated using principal component analysis by analyzing action potentials after short perturbations from the steady state, and mean eigenvalues (λ[over ¯]) were calculated separately for the 1:1 and 1:1(alt) regions. We demonstrated that λ[over ¯] calculated at B(onset) was significantly different (p<0.05) between the two regions. Our results suggest that this dominant eigenvalue technique can be used to successfully predict the local alternans formation in the heart. |
12,370 | Blunt cardiac injury with scintigraphic perfusion-metabolism mismatch. | A healthy 37-year-old man who bruised his chest with a steel frame developed ventricular fibrillation, pulseless ventricular tachycardia, and temporary torsade de pointes, and was resuscitated with emergency medical treatment. Thallium 201 scintigraphy 7 days later revealed a defect only in a small area of the apex, whereas 123</sup> I-beta-methyl iodophenyl pentadecanoic acid scintigraphy showed defects in a larger area of the apex, ventricular septum, and inferior wall, indicating perfusion-metabolism mismatch. Follow-up dual myocardial scintigraphy on day 49 showed that the scintigraphic defects persisted only at a small area of the apex.</AbstractText>Blunt external force appeared to have caused perfusion-metabolism mismatch and subsequent life-threatening arrhythmias in this patient.</AbstractText> |
12,371 | A case of primary aldosteronism who experienced cardiopulmonary arrest, was resuscitated and cured. | A 45-year-old female went into cardiopulmonary arrest. She was in ventricular fibrillation (VF) and was defibrillated using an automated external defibrillator. After arrival at our hospital, electrocardiography monitoring showed QT prolongation. Serum potassium was low at 2.2 mEq/L, and hypokalemia-induced long QT syndrome was considered to be the cause of this patient's VF. An intravenous infusion of potassium and magnesium sulphate was started, which normalized her serum potassium and QTc interval, with no recurrence of ventricular arrhythmias. Endocrinological investigations showed a plasma renin activity of <0.1 ng/(mL h) and a plasma aldosterone concentration 258 pg/mL. Computed tomography scanning revealed a low signal area 16 mm × 20 mm in size of the right adrenal gland. From the above findings, this patient was diagnosed with a right adrenal tumor and primary aldosteronism. We concluded that the right adrenal tumor was excreting excess amounts of aldosterone from adrenal vein sampling, and performed laparascopic right adrenalectomy. Serum potassium levels rose immediately to normal levels postoperatively. We were able to withdraw her antihypertensive medication 3 months after adrenalectomy. We report a case of primary aldosteronism who experienced cardiopulmonary arrest, was resuscitated, and cured. <<b>Learning objective:</b> When you come across ventricular fibrillation, please consider one of the reasons is caused by hypokalemia due to primary aldosteronism. After an appropriate resuscitation, both hypokalemia and hypertension are completely curable by removing the adrenal tumor.>. |
12,372 | Anomalous origin of the left coronary artery from pulmonary artery a late presentation-Case report and review of literature. | An otherwise healthy 26-year-old female presented with sudden cardiac arrest. She was resuscitated with unsynchronized cardioversion for ventricular fibrillation. A left heart cardiac catheterization showed anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA). Cardiac computed tomographic angiography confirmed this abnormality. She underwent direct translocation of the left main coronary artery to the aorta, and after a stormy postoperative course was discharged home. ALCAPA is a rare congenital abnormality of the coronary system that is associated with early infant mortality and adult sudden death. The use of advanced cardiac imaging has resulted in an increase in the number of diagnosed ALCAPA cases, especially in the adult population, sometimes even in the asymptomatic. The extent of collateral circulation that develops between the right coronary artery and the left coronary artery determines the outcome; the more collateral circulation there is, the less the hypoxic damage to the ventricle. This not only informs us that people survive ALCAPA into adulthood but also highlights the importance for adult cardiologists to be aware of this interesting disease. Corrective surgery remains the treatment of choice. We present a rare case of ALCAPA, with first presentation in adulthood in the form of a malignant ventricular arrhythmia. <<b>Learning objective:</b> Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital abnormality of the coronary system that is associated with early infant mortality and adult sudden death. Hence we feel it is most important to be aware of this entity, especially as the incidence of diagnosed ALCAPA is on the rise in adulthood. Also the images provided and the discussion have high educational value for generalists and cardiologists alike.>. |
12,373 | Post-operative simultaneous very late two-vessel drug eluting stent thrombosis with sparing of bare metal stent in a Jehovah's witness after clopidogrel withdrawal. | Very late stent thrombosis is a feared complication after drug-eluting stent (DES) implantation. Several factors related to the patient, generation and type of the deployed stent, procedure, and premature antiplatelet withdrawal are known to contribute to this complication. Herein, we describe a case of a Jehovah's witness patient who developed simultaneous two-vessel 1st generation DES thrombosis 5.4 and 3.5 years after deployment [with sparing of the bare metal stent (BMS)] in the immediate post-operative period secondary to clopidogrel withdrawal. The case was complicated by ST-segment elevation myocardial infarction, cardiogenic shock, and a ventricular fibrillation cardiac arrest requiring urgent percutaneous coronary intervention. The acute thrombosis of DESs with sparing of the BMS exemplify how they are more prone to this complication due to delayed endothelialization of stent struts and neoinitimal coverage. <<b>Learning objective:</b> Extreme caution should be excercised when attempting to withdraw antiplatelets immediately before surgery in patients with drug eluting stents even if the recomended 12-month period of dual antiplatelet therapy has elapsed because of the risk of very late stent thrombosis.>. |
12,374 | Anaphylactic shock associated with intravenous amiodarone. | A 64-year-old woman was admitted to our emergency department with shortness of breath and palpitation which started 2 h before her admission. She had a history of rheumatic mitral valve disease and was on drug treatment with warfarin and metoprolol. The patient was orthopneic, blood pressure was 108/68 mmHg with an irregular pulse with a heart rate of 158 beats per minute, and respiratory rate was 23 times per minute. Her electrocardiogram was consistent with atrial fibrillation with rapid ventricular response. For pharmacological cardioversion the patient was given amiodarone intravenous loading dose of 300 mg in 30 min. After 10 min of infusion the patient complained of pruritus and skin rash consistent with urticaria. At the same time the patient had dyspnea and bronchoconstriction was noted on both lung fields. The blood pressure was measured as 64/40 mmHg. The patient was taken to intensive care unit and supportive treatment for anaphylactic shock was given. Amiodarone is a class III antiarrhythmic agent frequently used in the management of atrial fibrillation. This potentially fatal complication of amiodarone should be kept in mind by clinicians and before administration patients should be questioned about previous allergic reactions including previous iodine or iodinated contrast media. Alternative agents should be considered in these conditions. <<b>Learning objective:</b> Anaphylactic shock is a rare complication of amiodarone and it is a commonly used drug. This potentially fatal complication of amiodarone should be kept in mind by clinicians.>. |
12,375 | Percutaneous balloon dilation of severe pulmonary valve stenosis in patients with cyanosis and congestive heart failure. | This article reports outcomes of percutaneous balloon dilation in patients with severe pulmonary valve stenosis, in particular in those treated late with cyanosis, congestive heart failure, and pericardial effusion.</AbstractText>Percutaneous balloon dilation is the treatment of choice for pulmonary valve stenosis. Although earlier intervention may produce better results, patients may present late with congestive heart failure and cyanosis.</AbstractText>Fifty-five patients who underwent pulmonary valve balloon dilation, were grouped into two groups, based on the presence or absence of congestive right heart failure and/or central cyanosis. Group I included 33 patients with severe pulmonary valve stenosis, but without clinical evidence of congestive right heart failure in the form of liver enlargement, raised jugular venous pressure, and peripheral edema and/or central cyanosis and group II included 22 patients with severe pulmonary valve stenosis and congestive right heart failure and/or central cyanosis. Their outcomes were compared.</AbstractText>Doppler measured transvalvar pressure gradient decreased from 110.2 ± 34.0 mm Hg before to 52.5 ± 28.7 mm Hg in group I after dilation (P < 0.001), and from 138.4 ± 32.3 mm Hg to 53.9 ± 19.3 mm Hg in group II, (P < 0.001). Complications included ventricular tachycardia/fibrillation in three patients and severe bradycardia in one patient in group II. Twelve patients in group II developed clinical and radiologic evidence of reperfusion injury/pulmonary edema within the first 24 hr of intervention and needed ventilation for 2-9 days. Three of these patients died from intractable pulmonary edema. On follow up, clinical and echocardiographic improvement parameters were similar in the two groups.</AbstractText>Those patients with severe pulmonary valve stenosis with congestive right heart failure, especially those with pericardial effusion, ascites and cyanosis, represent an important technical and clinical challenge. They are a high-risk group with or without treatment. If they survive the procedure, they may still remain at a high risk in the first few days afterward. Maintaining their ventilator and inotropic support after balloon dilation may increase survival. However, excellent results can be obtained.</AbstractText>© 2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,376 | Evaluation of pre-hospital administration of adrenaline (epinephrine) by emergency medical services for patients with out of hospital cardiac arrest in Japan: controlled propensity matched retrospective cohort study. | To evaluate the effectiveness of pre-hospital adrenaline (epinephrine) administered by emergency medical services to patients with out of hospital cardiac arrest.</AbstractText>Controlled propensity matched retrospective cohort study, in which pairs of patients with or without (control) adrenaline were created with a sequential risk set matching based on time dependent propensity score.</AbstractText>Japan's nationwide registry database of patients with out of hospital cardiac arrest registered between January 2007 and December 2010.</AbstractText>Among patients aged 15-94 with out of hospital cardiac arrest witnessed by a bystander, we created 1990 pairs of patients with and without adrenaline with an initial rhythm of ventricular fibrillation or pulseless ventricular tachycardia (VF/VT) and 9058 pairs among those with non-VF/VT.</AbstractText>Overall and neurologically intact survival at one month or at discharge, whichever was earlier.</AbstractText>After propensity matching, pre-hospital administration of adrenaline by emergency medical services was associated with a higher proportion of overall survival (17.0% v 13.4%; unadjusted odds ratio 1.34, 95% confidence interval 1.12 to 1.60) but not with neurologically intact survival (6.6% v 6.6%; 1.01, 0.78 to 1.30) among those with VF/VT; and higher proportions of overall survival (4.0% v 2.4%; odds ratio 1.72, 1.45 to 2.04) and neurologically intact survival (0.7% v 0.4%; 1.57, 1.04 to 2.37) among those with non-VF/VT.</AbstractText>Pre-hospital administration of adrenaline by emergency medical services improves the long term outcome in patients with out of hospital cardiac arrest, although the absolute increase of neurologically intact survival was minimal.</AbstractText> |
12,377 | Cardiac arrest during anesthesia at a university Hospital in Nigeria. | We assessed the incidence and outcomes of cardiac arrest during anesthesia in the operating room at our university hospital. A previous study on intraoperative cardiac arrests covered a period from 1994-1998 and since then; anesthetic personnel, equipment, and workload have increased remarkably.</AbstractText>After obtaining institutional ethics approval, we retrospectively reviewed patients' hospital records such as anesthetic charts and register and ICU admission charts between 1 st July 2005 and 30 th June 2010. The cardiac arrests encountered during anesthesia was identified from anesthetic charts and followed-up in the intensive care unit (ICU) for the first 24 h postoperatively. We consider that cardiac arrest occurred in any patient under anesthesia with asystole or ventricular fibrillation requiring cardiac compression or electrical defibrillation. We define recovery as an alive and non-comatose patient 24-h after the cardiac arrest.</AbstractText>During the study period, a total of 12,143 surgeries were done; the median age of all the patients was 30 years (range: 1 day-119 years). A total of 31 cardiac arrests identified (frequency 25.5:10,000; 95% confidence interval (CI) 17.7-35.8) out of which 17 were nonfatal. Mortality related to anesthesia was 11.5:10,000 (95% CI 6.5-18.9). The median age of patients with cardiac arrests was 39 years (range: 2 months-78 years). Overall, 80.7% cardiac arrests occurred in the American Society of Anesthesiologists' (ASA) physical status 3-5. Cardiothoracic and neurosurgical operations accounted for 54.8% of the total cardiac arrests. The known risk factors identified among those who had cardiac arrest were, ASA physical status 3-5 (80.7%), procedures performed out-of-work hours (60%), and manually ventilating patients during general anesthesia (39%).</AbstractText>Cardiac arrest during anesthesia is higher in poor risk patients (ASA 3-5) who are manually ventilated under general anesthesia and operated during out-of-work hours.</AbstractText> |
12,378 | [The pacemaker and implantable cardioverter-defibrillator registry of the Italian Association of Arrhythmology and Cardiac Pacing - Annual Report 2012]. | The pacemaker (PM) and implantable cardioverter-defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) monitors the main epidemiological data in real-world practice. The survey for the 2012 activity collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers.</AbstractText>The Registry collects prospectively national PM and ICD implantation activity on the basis of European cards.</AbstractText>PM Registry: data about 25 611 PM implantations were collected (18 870 first implant and 6741 replacements). The number of collaborating centers was 245. Median age of treated patients was 80 years (74 quartile I; 86 quartile III). ECG indications included atrioventricular conduction disorders in 41.9% of first PM implants, sick sinus syndrome in 26.0%, atrial fibrillation plus bradycardia in 13.7%, other in 18.4%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (21.7% of first implants). Use of single-chamber PMs was reported in 29.0% of first implants, of dual-chamber PMs in 61.3%, of PMs with cardiac resynchronization therapy (CRT) in 1.7%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 8.0%. ICD REGISTRY: data about 16 606 ICD implantations were collected (11 393 first implants and 5213 replacements). The number of collaborating centers was 427. Median age of treated patients was 71 years (62 quartile I; 77 quartile III). Primary prevention indication was reported in 68.6% of first implants, secondary prevention in 31.4% (cardiac arrest in 9.0%). A single-chamber ICD was used in 29.4% of first implants, dual-chamber in 37.6% and biventricular in 32.9%.</AbstractText>The PM and ICD Registry appears fundamental for monitoring PM and ICD utilization on a large national scale with rigorous examination of demographics and clinical indications. The PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The use of CRT-PM regards a very limited number of patients. The ICD Registry documented a constant increase in prophylactic and biventricular ICD use, reflecting a favorable adherence to trials and guidelines in clinical practice.</AbstractText> |
12,379 | Reversible cardiomyopathy after radiofrequency ablation of 30-year persistent atrial tachycardia. | Tachycardia-induced cardiomyopathy (TIC) is a reversible form of the left ventricular (LV) systolic dysfunction and is believed to be a relatively acute process. We report a TIC case with a 30-year history of long-lasting persistent atrial tachycardia involving a 44-year-old man previously diagnosed with dilated cardiomyopathy and a low LV ejection fraction (LVEF) of 20%. ECG revealed atrial tachycardia at 110-120 bpm. He was hospitalised with a worsening heart failure. His clinical status was New York Heart Association functional class III, and echocardiography revealed LV dilation and an LVEF of 9%. A two-dimensional speckle-tracking strain measurement revealed LV mechanical dyssynchrony. He underwent radiofrequency ablation for atrial tachycardia. After restoring sinus rhythm, his cardiac symptoms improved immediately. The LV mechanical dyssynchrony decreased a week after ablation, without changes in the LV dilation or LVEF. Thereafter, the LV dilation and systolic function gradually improved, and atrial tachycardia and heart failure remained absent. |
12,380 | Pilot evaluation of an integrated monitor-adhesive patch for long-term cardiac arrhythmia detection in India. | Electrocardiographic monitoring represents one of the most reliable and time-tested methods for reducing ambiguity in cardiac arrhythmia diagnosis. In India, the resting ECG is generally the first tool of choice for in-clinic diagnosis. The external loop recorder (ELR) is another useful tool that compounds the advantages of traditional tools by coupling ambulatory monitoring with a long-term window. Thus, the objective was to test the use of a 7-day ELR for arrhythmia diagnosis in India for a broad range of presenting symptoms. In this study set in the Indian healthcare environment, an auto-triggered, wireless patch-type ELR was used with 125 patients (62.5 ± 16.7 years, 76 males) presenting a broad range of symptoms. Eighty percent of the symptoms were related to syncope, presyncope or palpitations. Patients were administered an ELR for 7-28 days depending on the physician's prescription. Prespecified significant arrhythmias included sinus pause >2 s, symptomatic bradycardia <40 b.p.m., second-degree (and higher) AV block, complete heart block, ventricular fibrillation, sustained/nonsustained ventricular tachycardia (>3 beats), atrial fibrillation (chronic or paroxysmal), atrial flutter and supraventricular tachycardia (SVT) >130 b.p.m. Diagnostic yield was 38% when a stringent tabulation methodology considering only clinically significant arrhythmia was used. When first-degree AV block, premature atrial and ventricular beats, couplets (both atrial and ventricular in origin), bigeminy or trigeminy, or sudden changes in rate (noted as sinus arrhythmia) were included in the calculation, diagnostic yield was 80%. Patient compliance was 98%; patients wore the patch for the entire prescribed monitoring period without disruption. Seventy percent of the reported symptoms corresponded with an arrhythmia. Use of the ELR led to therapy change in 24% of patients: 15 patients went on to receive an implantable cardioverter defibrillator or pacemaker, 4 received ablation therapy and 11 altered their medication after diagnosis. This study demonstrates that a high diagnostic yield for clinically significant arrhythmias and high patient compliance can be achieved with a wearable patch monitor in Indian patients suffering from a variety of symptoms. |
12,381 | Changes in left ventricular filling in patients with persistent atrial fibrillation. | Former studies showed possible interrelationship between altered ventricular filling patterns and atrial fibrillation (AF).</AbstractText>Long term persistent AF has a negative impact on left ventricular filling in patients with preserved ejection fraction of left ventricle.</AbstractText>Our study was designed as a prospective case control study. We included 40 patients with persistent AF and preserved ejection fraction after successful electrical cardioversion and 43 control patients. Persistent AF was defined as AF lasting more than 4 weeks. Cardiac ultrasound was performed in all patients 24 hours after the procedure. Appropriate mitral flow and tissue Doppler velocities as well as standard echocardiographic measurements were obtained.</AbstractText>There were no significant differences between both groups' parameters regarding age, sex, commorbidities or drug therapy. Analysis of mitral flow velocities showed significant increase of E value in AF group (0.96±0.27 vs.0.70±0.14; p = 0.001). Tissue Doppler measurements didn't reveal any differences in early diastolic movement, however there was a statistically significant difference in E/Em values of both groups, respectively (12.0±4.0 vs. 9.0±2.1; p= 0.001).</AbstractText>Our study shows that in patients with preserved systolic function and persistent AF shortly after cardioversion diastolic ventricular filling patterns are altered mainly due to increased left atrial pressure and not due to impaired diastolic relaxation of left ventricle. Further studies are needed in order to define the interplay between diminished atrial function and impaired ventricular filling.</AbstractText> |
12,382 | A translational approach to probe the proarrhythmic potential of cardiac alternans: a reversible overture to arrhythmogenesis? | Electrocardiographic alternans, a phenomenon of beat-to-beat alternation in cardiac electrical waveforms, has been implicated in the pathogenesis of ventricular arrhythmias and sudden cardiac death (SCD). In the clinical setting, a positive microvolt T-wave alternans test has been associated with a heightened risk of arrhythmic mortality and SCD during medium- and long-term follow-up. However, rather than merely being associated with an increased risk for SCD, several lines of preclinical and clinical evidence suggest that cardiac alternans may play a causative role in generating the acute electrophysiological substrate necessary for the onset of ventricular arrhythmias. Deficiencies in Ca(2+) transport processes have been implicated in the genesis of alternans at the subcellular and cellular level and are hypothesized to contribute to the conditions necessary for dispersion of refractoriness, wave break, reentry, and onset of arrhythmia. As such, detecting acute surges in alternans may provide a mechanism for predicting the impending onset of arrhythmia and opens the door to delivering upstream antiarrhythmic therapies. In this review, we discuss the preclinical and clinical evidence to support a causative association between alternans and acute arrhythmogenesis and outline the potential clinical implications of such an association. |
12,383 | Totally endoscopic robotic coronary artery bypass surgery. | To assess the current status and methods of robotic totally endoscopic coronary artery bypass (TECAB) surgery and discuss important anesthetic considerations.</AbstractText>Technological and surgical advances in robotics have led to the evolution of TECAB surgery from a single-vessel procedure to quadruple-vessel bypass. TECAB is now a reproducible technique, with a low incidence of mortality and morbidity and superior quality of life. Although early cohorts of patients are still being observed for long-term outcomes, initial and midterm outcomes are comparable to those of conventional coronary artery bypass. TECAB is also associated with specific challenges for the anesthesiologist.</AbstractText>TECAB surgery is a feasible alternative to open coronary artery bypass surgery in selected patient populations. Appropriate patient selection, team training, and stepwise application of the procedure are crucial. TECAB is associated with a unique set of challenges, requiring a skilled operative team. As robotic technology and surgical expertise evolve, this technology will find wider application in an increasing high-risk patient population that will require the support of a skilled anesthesiology team.</AbstractText> |
12,384 | Effect of preoperative symptoms on outcomes after valve repair for degenerative aortic insufficiency. | This study evaluated the effect of preoperative symptoms on long-term survival and valve reintervention in patients undergoing aortic valve repair (AVr) for severe degenerative aortic insufficiency (AI).</AbstractText>Between March 1996 and June 2010, 274 patients underwent AVr for severe AI. Seventy-seven were performed in asymptomatic patients (Group I) and 197 were performed in symptomatic (Group II). Patients in Group I were younger (43.9 ± 15.0 vs 54.1 ± 15.5 years; P < 0.001) with a higher proportion of bicuspid valves (n = 40, 51.9% vs n = 68, 30.4%; P = 0.008). Group II had more patients with impaired left ventricular (LV; n = 36, 18.3% vs n = 5, 6.4%; P = 0.013). The mean follow-ups for Group I and Group II were 43.0 ± 34.0 and 61.3 ± 39.5 months, respectively.</AbstractText>There was no in-hospital mortality. Overall, leaflet repair and reimplantation were higher in Group I (P = < 0.001 and P = 0.002, respectively), whereas subcommissural annuloplasty for tricuspid AV was higher in Group II (P = 0.002). Leaflet shaving and plication were performed in more patients in Group I (P = 0.002 for both). There was no difference in early complications, but during follow-up atrial fibrillation was more frequent in Group II (P = 0.03). There were 10 late cardiac deaths, all in Group II (P = 0.04). Overall, 10-year cardiac survival was better in Group I (100 vs 77.3 ± 8.6%) but not significant (P = 0.1). At 10 years, freedom from ≥ AI2+ was 63.2 ± 8.1 vs 56.4 ± 4.5% (P = 0.4), and freedom from AV reintervention was 81.8 ± 7.1 vs 89.0 ± 2.8% (P = 0.36), in Groups I and II, respectively. In the whole cohort, 10-year freedom from AV reintervention was greater in patients with an end-diastolic diameter of <60 mm (90.0 ± 7.6 vs 76.3 ± 5.5%; P = 0.003). Multivariate analysis identified increasing age as the only independent predictor of overall survival (P = 0.03). The incidence of valve-related complications was similar.</AbstractText>In asymptomatic patients with severe degenerative AI, AVr is associated with excellent long-term outcomes, while symptoms are associated with reduced long-term survival. In dilated LV, freedom from reoperation is lower. If feasible, early AVr is recommended in experienced centres.</AbstractText> |
12,385 | Inappropriate subcutaneous implantable cardioverter-defibrillator shocks due to T-wave oversensing can be prevented: implications for management. | Inappropriate shocks (IASs) complicate implantable cardioverter-defibrillator (ICD) therapy. The management of IASs in patients with a subcutaneous ICD (S-ICD) differs from that in patients with a conventional ICD because of different sensing algorithms and programming options.</AbstractText>To describe the management of IASs in patients with an S-ICD.</AbstractText>Patients were implanted with an S-ICD between February 2009 and July 2012. The prevalence data and clinical determinants of IASs were prospectively collected. In the case of T-wave oversensing (TWOS), an exercise test was performed, and all possible sensing vectors were screened for TWOS. The absence of TWOS defined a suitable vector.</AbstractText>Eleven of 69 patients (54% men; mean age 39 ± 14 years; 73% primary prevention) received IASs after 8.9 ± 10 months of implantation (10.8% annual incidence rate). In 8 cases, TWOS caused IASs. Seven of these IASs occurred during exercise and 1 during atrial fibrillation with a high ventricular rate. To manage TWOS, in 7 of 8 patients the sensing vector was changed and in 5 of 8 patients the (un)conditional zone was changed. Hereafter, IASs recurred in 3 of 8 patients, in 2 because of programming errors. Hence, after reprogramming, we observed no IASs in 87.5% of the patients with TWOS during a follow-up of 14.1 ± 13 months.</AbstractText>IASs due to TWOS in the S-ICD can be managed by reprogramming the sensing vector and/or the therapy zones of the device using a template acquired during exercise. Exercise-optimized programming can reduce future IASs, and standard exercise testing shortly after the implantation of an S-ICD may be considered in patients at an increased risk for TWOS.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,386 | Nonsense-mediated mRNA decay due to a CACNA1C splicing mutation in a patient with Brugada syndrome. | Brugada syndrome (BrS) is an inherited cardiac arrhythmia associated with sudden death due to ventricular fibrillation. Mutations in genes related to the cardiac L-type calcium channel have been reported to be causative of BrS. Generally, the messenger RNA (mRNA) that contains a nonsense mutation is rapidly degraded via its decay pathway, which is known as nonsense-mediated mRNA decay (NMD). Previously, we reported a male patient with BrS who carried c.1896G>A (the first nucleotide of CACNA1C exon 14), which caused a synonymous mutation, p.R632R.</AbstractText>To examine how the synonymous CACNA1C mutation p.R632R produces the phenotype of BrS, with a special emphasis on the splicing error and NMD processes.</AbstractText>We extracted mRNA from leukocytes of the proband and his 2 children and performed reverse transcription polymerase chain reaction. Complementary DNAs were checked by using direct sequencing and quantitative analysis.</AbstractText>The subsequent sequence electropherogram of the complementary DNAs did not show the substitution of the nucleotide identified in the genomic DNA of the proband. In the mRNA quantification analysis, we confirmed that reduction in the CACNA1C expression level was suspected to be caused by NMD.</AbstractText>Mutant mRNA with a c.1896G>A substitution may be diminished by NMD, and the resultant decrease in CACNA1C message leads to a novel mechanism for inducing BrS that is distinct from that reported previously.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,387 | Left atrial booster-pump function as a predictive parameter for new-onset postoperative atrial fibrillation in patients with severe aortic stenosis. | Postoperative atrial fibrillation (POAF) is associated with increased risk of embolic events and heart failure, but its associated factors remains unknown. Left atrial (LA) subclinical mechanical dysfunction caused by the acute stress of surgery may be clinically manifested as POAF. The purpose of our study was therefore to test the hypothesis that preoperative LA subclinical myocardial dysfunction is a potential predictor of development of POAF in patients with aortic stenosis (AS). We studied 27 patients with severe AS undergoing aortic valve replacement (AVR) with left ventricular (LV) ejection fraction of 63 ± 11 %. All patients were in sinus rhythm and had no history of atrial fibrillation (AF). LA reservoir (SR-LAs), conduit (SR-LAe), and booster-pump (SR-LAa) functions were determined as the averaged global LA speckle-tracking longitudinal strain rates from apical four- and two-chamber views. POAF, defined as any episode of AF within 30-day after AVR, was observed in 15 patients (56 %). There were no differences in clinical characteristics, LA and LV volumes, and global LV function between patients with and without POAF. Multivariate logistic regression analysis identified SR-LAa as the only independent predictor of POAF. Furthermore, SR-LAa >0.79 s(-1) predicted POAF with 60 % sensitivity, 92 % specificity, and area under the curve of 0.828 (p < 0.0001). Of the 15 patients with POAF, one developed paroxysmal AF during long-term follow-up. In conclusions, SR-LAa helped to detect subtle LA booster-pump dysfunction and was associated with new-onset POAF in patients with severe AS. These findings may be useful for risk stratification and management of such patients. |
12,388 | Pulmonary arterial systolic pressure and E/e' in the evaluation of left ventricular filling pressure: assessment of patients with atrial fibrillation. | Echocardiographic assessments including E/e' are a good predictor of elevated left ventricular (LV) filling pressure during sinus rhythm. However, the evaluation of LV filling pressure using classic echocardiographic assessment has been challenging in the setting of atrial fibrillation (AF). The aim of this study was to investigate the methods for predicting LV filling pressure in patients with chronic AF.</AbstractText>Clinical data, echocardiography findings, and brain natriuretic peptide (BNP) levels were assessed in 59 patients with chronic AF who were undergoing diagnostic left-heart catheterization. LV end-diastolic filling pressure (LVEDP) and standard echocardiographic measurements including pulmonary arterial systolic pressure (PASP) were evaluated. Blood samples were taken for serum BNP measurements within 24 h of the echocardiographic examination.</AbstractText>E/e' correlated well with LVEDP (r = 0.558, p < 0.001). Using receiver operating characteristic analysis, the optimal cut-off for E/e' was 16 (sensitivity, 64 %; specificity, 82 %) to predict LVEDP of > 15 mmHg. PASP was also well correlated with LVEDP (r = 0.503, p < 0.001). PASP greater than 32 mmHg predicted elevated LVEDP (> 15 mmHg) with a sensitivity of 64 % and a specificity of 71 %.</AbstractText>E/e' and PASP were well correlated with LVEDP in patients with AF. PASP greater than 32 mmHg and E/e' greater than 16 may suggest elevated LVEDP (> 15 mmHg) in patients with chronic AF.</AbstractText> |
12,389 | SCN5A mutation in Chinese patients with arrhythmogenic right ventricular dysplasia. | Arrhythmogenic right ventricular dysplasia (ARVD) is a genetically determined disorder, characterized by two components: cardiomyopathy and arrhythmia. To date, the ion channel-related pathogenesis underlying this phenomenon has been poorly understood. The aim of this study was to systematically evaluate the sodium channel variants in Chinese patients with ARVD.</AbstractText>Patients meeting the diagnostic guidelines of ARVD revised in 2010 were enrolled. All exons and exon-intron boundaries of the SCN5A gene and desmosomal genes known to be associated with ARVD, including DSC2, DSG2, DSP, JUP, and PKP2, were sequenced by direct DNA sequencing. A total of 12 unrelated index patients were included in the study.</AbstractText>Eight of the patients developed ventricular tachycardia (VT) and ventricular fibrillation (VF), one of them showed epsilon wave, one of them showed type-1 Brugada wave, seven of them exhibited syncope or dizziness, and none of the patients had a family history of SCD. A new missense heterozygote mutation, I137M, in SCN5A was found in proband 5 with recurrent palpitations and a high incidence of VT. I137M is in exon 4 of SCN5A, at the S1 segment in domain I of Nav1.5, which predicted a substitution of isoleucine for methionine at codon site 137 (p. Ile137Met, I137M). I137M was not detected in 400 healthy control chromosomes from individuals of the same ethnic background, which indicated that this mutation was a conservative site in the SCN5A gene, and the encoded protein Nav1.5 might have a functional defect resulting in arrhythmia.</AbstractText>This was the first study to systematically investigate sodium channel variants in Chinese patients with ARVD; a new SCN5A mutation, I137M, was found. This finding may provide new evidence of the genetic pathogenesis of ARVD in Chinese patients, implying that the SCN5A gene should be screened in patients with ARVD and VT/VF.</AbstractText> |
12,390 | Left ventricular geometry and outcomes in patients with atrial fibrillation: the AFFIRM Trial. | Echocardiographically determined left ventricular hypertrophy (LVH) is a marker of cardiovascular disease related to prognosis and clinical outcomes. We sought to determine if LVH is a measure of outcomes in atrial fibrillation (AF) patients.</AbstractText>We performed a post-hoc analysis of patients with echocardiographic data enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Trial. Patients were stratified based on gender-adjusted echocardiography derived interventricular septal (IVS) thickness, relative wall thickness (RWT), gender-adjusted LV mass, and type of LV remodeling (normal LV geometry, concentric hypertrophy, eccentric hypertrophy, and concentric remodeling).</AbstractText>Of 4060 patients in AFFIRM, echocardiographic data were available in 2433 patients (60%). Multivariate analysis revealed that LVH defined as moderately or severely abnormal IVS thickness was an independent predictor of both all cause mortality (HR 1.46, 95%CI 1.14-1.86, p=0.003) and stroke (HR 1.89, 95%CI 1.17-3.08, p=0.01). This association was confirmed when IVS thickness was assessed as continuous or categorical variable. Concentric LV hypertrophy was associated with the highest rates of all cause mortality (HR 1.53; 95%CI 1.11-2.12; p=0.009).</AbstractText>An easily obtained echocardiographic index of LVH (IVS thickness) may enhance risk stratification of patients with AF, and raise the possibility that LVH regression should be a therapeutic target in this population.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,391 | Early repolarization, acute emotional stress and sudden death. | We herein report the case of a 36-year-old man who died suddenly after a fight with another man. Forensic investigations included unenhanced computed tomography, postmortem angiography, autopsy, histology, neuropathology, toxicology, and biochemistry and allowed a traumatic cause of death to be excluded. An electrocardiogram recorded some years prior to death revealed the presence of an early repolarization pattern. Based on the results of all investigations, the cause of death was determined to be cardiac arrhythmia and cardiac arrest during an emotionally stressful event associated with physical assault. Direct third party involvement, however, was excluded, and the manner of death was listed as natural. The case was not pursued any further by the public prosecutor. |
12,392 | Obesity is associated with lower coronary microvascular density. | Obesity is associated with diastolic dysfunction, lower maximal myocardial blood flow, impaired myocardial metabolism and increased risk of heart failure. We examined the association between obesity, left ventricular filling pressure and myocardial structure.</AbstractText>We performed histological analysis of non-ischemic myocardium from 57 patients (46 men and 11 women) undergoing coronary artery bypass graft surgery who did not have previous cardiac surgery, myocardial infarction, heart failure, atrial fibrillation or loop diuretic therapy.</AbstractText>Non-obese (body mass index, BMI, ≤ 30 kg/m(2), n=33) and obese patients (BMI >30 kg/m(2), n=24) did not differ with respect to myocardial total, interstitial or perivascular fibrosis, arteriolar dimensions, or cardiomyocyte width. Obese patients had lower capillary length density (1145 ± 239, mean ± SD, vs. 1371 ± 333 mm/mm(3), P=0.007) and higher diffusion radius (16.9 ± 1.5 vs. 15.6 ± 2.0 μm, P=0.012), in comparison with non-obese patients. However, the diffusion radius/cardiomyocyte width ratio of obese patients (0.73 ± 0.11 μm/μm) was not significantly different from that of non-obese patients (0.71 ± 0.11 μm/μm), suggesting that differences in cardiomyocyte width explained in part the differences in capillary length density and diffusion radius between non-obese and obese patients. Increased BMI was associated with increased pulmonary capillary wedge pressure (PCWP, P<0.0001), and lower capillary length density was associated with both increased BMI (P=0.043) and increased PCWP (P=0.016).</AbstractText>Obesity and its accompanying increase in left ventricular filling pressure were associated with lower coronary microvascular density, which may contribute to the lower maximal myocardial blood flow, impaired myocardial metabolism, diastolic dysfunction and higher risk of heart failure in obese individuals.</AbstractText> |
12,393 | Ventricular remodelling in rabbits with sustained high-fat diet. | Excess weight gain and obesity are one of the most serious health problems in the western societies. These conditions enhance risk of cardiac disease and have been linked with increased prevalence for cardiac arrhythmias and sudden death. Our goal was to study the ventricular remodelling occurring in rabbits fed with high-fat diet (HFD) and its potential arrhythmogenic mechanisms.</AbstractText>We used 15 NZW rabbits that were randomly assigned to a control (n = 7) or HFD group (n = 8) for 18 weeks. In vivo studies included blood glucose, electrocardiographic, and echocardiographic measurements. Optical mapping was performed in Langendorff-perfused isolated hearts.</AbstractText>Body weight (3.69 ± 0.31 vs. 2.94 ± 0.18 kg, P < 0.001) and blood glucose levels (230 ± 61 vs. 141 ± 14 mg dL(-1) , P < 0.05) were higher in the HFD group vs. controls. The rate-corrected QT interval and its dispersion were increased in HFD rabbits vs. controls (169 ± 10 vs. 146 ± 13 ms and 37 ± 11 vs. 9 ± 2 ms, respectively; P < 0.05). Echocardiographic analysis showed morphological and functional alterations in HFD rabbits indicative of left ventricle (LV) hypertrophy. Isolated heart studies revealed no changes in repolarization and propagation properties under conditions of normal extracellular K(+) , suggesting that extrinsic factors could underlie those electrocardiographic modifications. There were no differences in the dynamics of ventricular fibrillation (frequency, wave breaks) in the presence of isoproterenol. However, HFD rabbits showed a small reduction in action potential duration and an increased incidence of arrhythmias during hyperkalaemia.</AbstractText>High-fat feeding during 18 weeks in rabbits induced a type II diabetes phenotype, LV hypertrophy, abnormalities in repolarization and susceptibility to arrhythmias during hyperkalaemia.</AbstractText>© 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.</CopyrightInformation> |
12,394 | Risk of sudden cardiac death. | The aim of this study was to determine characteristics of patients with sudden cardiac arrest (SCA) and/or sudden cardiac death (SCD). We need an effective risk stratification method for SCD in patients without low left ventricular ejection fraction (LVEF).</AbstractText>The study population of this cross-sectional study consisted of 241 patients with SCA or SCD who were admitted to an academic hospital, in Tehran, Iran, from 2011 through 2012. SCD was defined as unexpected death from cardiac causes, heralded by abrupt loss of consciousness within one hour of the onset of acute changes in cardiovascular status, or an unobserved death in which the patient was seen and known to be doing well within the previous 24 hours. Survivors of aborted SCD were also included in the study. Clinical and paraclinical characteristics as well as emergency department complications of patients were recorded.</AbstractText>The mean age of population was 66.0 ± 16.5 (17 to 90 years). Among the patients, 166 (68.9 %) were male, 50 (20.7%) were smoker, 77 (32.0%) had hypertension, 47 (19.5%) had diabetes mellitus, 21 (8.7%) had hyperlipidemia, and 32 (13.3%) had renal insufficiency. According to New York Health Association (NYHA) functional class, 31 (12.9%) patients were asymptomatic, 42 (17.4) and 99 (41.1%) subjects were in NYHA I and II, respectively and only 69 (28.6%) patients were in NYHA III or IV. In this study, presenting arrhythmia was pulseless electrical activity or asystole which was observed in 130 (53.9%) subjects. Ventricular tachycardia (VT) or ventricular fibrillation (VF) was seen in 53 (22%) patients. Cardiopulmonary resuscitation in emergency room was successful only in 46 (19.1%) subjects.</AbstractText>Low ejection fraction (EF) may be an independent predictor of sudden cardiac death in patients, but it is not enough. While implantable cardioverter defibrillators can save lives, we are lacking effective risk stratification and prevention methods for the majority of patients without low EF who will experience SCD.</AbstractText> |
12,395 | Left atrial structure and function in atrial fibrillation: ENGAGE AF-TIMI 48. | The complex relationship between left atrial (LA) structure and function, electrical burden of atrial fibrillation (AF) and stroke risk is not well understood. We aimed to describe LA structure and function in AF.</AbstractText>Left atrial structure and function was assessed in 971 subjects enrolled in the echocardiographic substudy of ENGAGE AF-TIMI 48. Left atrial size, emptying fraction (LAEF), and contractile function were compared across AF types (paroxysmal, persistent, or permanent) and CHADS2 scores as an estimate of stroke risk. The majority of AF patients (55%) had both LA enlargement and reduced LAEF, with an inverse relationship between LA size and LAEF (R = -0.57, P < 0.001). With an increasing electrical burden of AF and higher CHADS2 scores, LA size increased and LAEF declined. Moreover, 19% of AF subjects had impaired LAEF despite normal LA size, and LA contractile dysfunction was present even among the subset of AF subjects in sinus rhythm at the time of echocardiography.</AbstractText>In a contemporary AF population, LA structure and function were increasingly abnormal with a greater electrical burden of AF and higher stroke risk estimated by the CHADS2 score. Moreover, LA dysfunction was present despite normal LA size and sinus rhythm, suggesting that the assessment of LA function may add important incremental information in the evaluation of AF patients.</AbstractText>http://www.clinicaltrials.gov; ID = NCT00781391.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2013. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
12,396 | Does a high percentage of right ventricular pacing influence the incidence of paroxysmal atrial fibrillation in myotonic dystrophy type 1 patients? | Paroxysmal atrial tachyarrhythmias occur frequently in myotonic dystrophy type 1 (MD1) patients. Pacemakers, implanted for the treatment of bradyarrhythmias and including detailed diagnostic functions, may facilitate the diagnosis and management of frequent paroxysmal atrial fibrillation (AF) that may remain undetected during a conventional clinical follow-up. The effect of right ventricular pacing on AF incidence is still controversial.</AbstractText>To evaluate the influence of a high percentage of right ventricular pacing on AF in MD1 patients during a 12-month follow-up period.</AbstractText>We enrolled in the present study 70 MD1 patients (age 51.3 ± 5 years; 32 females) who underwent dual chamber pacemaker implantation. At 12 months of follow-up, the study population was divided into three groups according to the percentage of atrial and ventricular stimulation: Group 1, the atrial sensing ventricular sensing group (ASVS; n = 22; age 52 ± 7.7; eight female) with a percentage of atrial and ventricular stimulation lower than 50%; Group 2, the atrial sensing ventricular pacing group (ASVP; n = 24; age 50.5 ± 7.6; 13 female) with a percentage of atrial stimulation lower than 50% and percentage of ventricular stimulation higher than 80%; and Group 3, the atrial pacing ventricular pacing group (APVP; n = 24; age 56 ± 4.3; 11 female) with a percentage of atrial and ventricular stimulation higher than 80%. We counted the number of episodes of atrial arrhythmia that occurred during the observation period and the duration of each episode.</AbstractText>We found a statistically significant difference in the number and duration of AF episodes between the three groups at the 12-month follow-up. In particular, there were more episodes (253 ± 30 vs. 80 ± 27 vs. 53 ± 32; p < 0.03) and longer durations of AF (8,700 ± 630 vs. 4,480 ± 975 vs. 3,853 ± 870 min; p < 0.03) in the ASVP group than in the ASVS group and the APVP group. Lead parameters remained stable over time and there were no displacements of the electrodes after implantation.</AbstractText>In a 12-month follow-up comparison, we showed a statistically significant increase in paroxysmal AF episodes in MD1 patients with a high percentage of right ventricular pacing and a lower percentage of atrial stimulation.</AbstractText> |
12,397 | Overexpression of KCNN3 results in sudden cardiac death. | A recent genome-wide association study identified a susceptibility locus for atrial fibrillation at the KCNN3 gene. Since the KCNN3 gene encodes for a small conductance calcium-activated potassium channel, we hypothesized that overexpression of the SK3 channel increases susceptibility to cardiac arrhythmias.</AbstractText>We characterized the cardiac electrophysiological phenotype of a mouse line with overexpression of the SK3 channel. We generated homozygote (SK3(T/T)) and heterozygote (SK3(+/T)) mice with overexpression of the channel and compared them with wild-type (WT) controls. We observed a high incidence of sudden death among SK3(T/T) mice (7 of 19 SK3(T/T) mice). Ambulatory monitoring demonstrated that sudden death was due to heart block and bradyarrhythmias. SK3(T/T) mice displayed normal body weight, temperature, and cardiac function on echocardiography; however, histological analysis demonstrated that these mice have abnormal atrioventricular node morphology. Optical mapping demonstrated that SK3(T/T) mice have slower ventricular conduction compared with WT controls (SK3(T/T) vs. WT; 0.45 ± 0.04 vs. 0.60 ± 0.09 mm/ms, P = 0.001). Programmed stimulation in 1-month-old SK3(T/T) mice demonstrated inducible atrial arrhythmias (50% of SK3(T/T) vs. 0% of WT mice) and also a shorter atrioventricular nodal refractory period (SK3(T/T) vs. WT; 43 ± 6 vs. 52 ± 9 ms, P = 0.02). Three-month-old SK3(T/T) mice on the other hand displayed a trend towards a more prolonged atrioventricular nodal refractory period (SK3(T/T) vs. WT; 61 ± 1 vs. 52 ± 6 ms, P = 0.06).</AbstractText>Overexpression of the SK3 channel causes an increased risk of sudden death associated with bradyarrhythmias and heart block, possibly due to atrioventricular nodal dysfunction.</AbstractText> |
12,398 | Delirium in patients admitted to a cardiac intensive care unit with cardiac emergencies in a developing country: incidence, prevalence, risk factor and outcome. | To assess the incidence, prevalence, risk factors and outcome of delirium in patients admitted to a cardiac intensive care unit (ICU) of a tertiary care hospital.</AbstractText>Three hundred nine consecutive patients admitted to a 22-bed coronary care unit were screened for presence of delirium by using Confusion Assessment Method for Intensive Care Unit (CAM-ICU), and those found positive on CAM-ICU were further evaluated by a psychiatrist to confirm the diagnosis of delirium as per DSM-IV-TR criteria. Patients were also evaluated for the risk factors for delirium and outcome of delirium.</AbstractText>Incidence rate of delirium was 9.27%, and prevalence rate was 18.77%. The risk factors identified for delirium in binary logistic regression analysis were hypokalemia, Sequential Organ Failure Assessment score, presence of cognitive deficits, receiving more than three medications, sepsis, hyponatremia, presence of cardiogenic shock, having undergone coronary artery bypass grafting, left ventricular ejection fraction <30, currently receiving opioids, age more than 65 years, presence of diabetes mellitus, presence of uncontrolled diabetes mellitus, history of seizures, presence of congestive cardiac failure, having undergone angioplasty, presence of atrial fibrillation, ongoing depression, currently receiving/taking benzodiazepines, warfarin, ranitidine, steroids, non-steroidal anti-inflammatory drugs, higher total number of medications, presence of raised creatinine, anaemia, hypoglycemia, Acute Physiology and Chronic Health Evaluation II score and Charlson Comorbidity Index score. About one fourth (n=22; 27%) of the patients who developed delirium died during the hospital stay in contrast to 1% mortality in the non-delirious group. Those with delirium also had longer stay in the ICU.</AbstractText>Delirium is highly prevalent in the cardiac ICU setting and is associated with presence of many modifiable risk factors. Development of delirium increases the mortality risk and is associated with longer cardiac ICU stay.</AbstractText>© 2013.</CopyrightInformation> |
12,399 | Cardioverter-defibrillator implantation in myeloma-associated cardiac amyloidosis. | A 62-year-old woman with multiple myeloma and light-chain amyloidosis with significant heart involvement developed an in-hospital cardiac arrest. After cardiopulmonary resuscitation, a stable sinus rhythm without any cerebral damage was restored, and the patient was admitted to the coronary care unit. A cardioverter-defibrillator was implanted, and it successfully intervened in two sustained ventricular tachycardia episodes and one ventricular fibrillation episode, which were recorded during hospitalization. After achieving discrete cardiac compensation, the patient was transferred to the emergency medicine department where she underwent chemotherapy for multiple myeloma. The patient died 40 days after admission from refractory heart failure. In the literature, there are studies that describe the use of cardioverter-defibrillator implantation in cardiac amyloidosis; however, at present, there is no evidence of a beneficial effect on survival with the use of this intervention. A high index of suspicion for amyloid heart disease and early diagnosis are critical to improving outcomes. |
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