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11,900 | The Evolving Utility Of Intracardiac Echocardiography In Cardiac Procedures. | Intracardiac echocardiography (ICE) has gained increasing use in electrophysiology due to the need to visualize key anatomic structures. Precise guidance for transseptal puncture and visualization of the pulmonary veins are common essential uses for ICE, but many operators adept at ICE imaging have developed additional and specific uses. With heavy use of ICE guidance, electrophysiologists demonstrated feasibility of left atrial ablation with minimal use of fluoroscopy. With the advent of 3D mapping-integrated ICE, rendering of contours for the left atrium, aortic cusps, and left ventricular structures such as the papillary muscles have become possible. Improved understanding of the anatomy of these areas can facilitate mapping and ablation of these structurally complex sites. Additional uses of scar-visualization and integration into voltage maps have been explored. Left atrial appendage imaging has been an area of interest in the ICE community, although technological improvements are likely needed to make this more reliably complete. A new real-time 3D ICE catheter has also been developed, and work is in progress to delineate potential uses for this new frontier. Increasingly routine use of ICE has led to improved real-time guidance of all percutaneous cardiac procedures. |
11,901 | A Case Of Difficult Epicardial Access For Ablation Of Ventricular Tachcyardia. | We present a case of a 67-year-old patient with nonischemic cardiomyopathy and recurrent sustained ventricular tachycardia of epicardial origin referred for ablation. Due to two previous episodes of cardiac tamponade secondary to implantable cardioverter-defibrillator lead perforation at the time of device implant, the patient had significant pericardial adhesions making epicardial access and ablation challenging. |
11,902 | Stroke And Bleeding Risk Assessment: Where Are We Now? | Atrial fibrillation (AF) is one of major problems of the contemporary cardiology. Ischaemic stroke is a common complication of the AF, and effective prophylaxis requires treatment with oral anticoagulants. The purpose of this current review article is to provide an overview of the various stroke and bleeding risk assessment scores that help decision making with respect to thromboprophylaxis. Particular focus is made on the currently guideline-recommended stroke and bleeding risk scores, such as CHA<sub>2</sub>DS<sub>2</sub>-VASc (congestive heart failure or left ventricular dysfunction, hypertension, age ≥75, diabetes, stroke, vascular disease, age 65-74 and sex category [female]) and HAS-BLED (uncontrolled hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly [e.g. age >65, frail condition], drugs [e.g. aspirin, nonsteroidal anti-inflammatory drugs]/excessive alcohol) is made. Future directions for improvement of predictive ability of risk assessment with clinical factors and biomarkers are also discussed. |
11,903 | Diastolic Function in Normal Sinus Rhythm vs. Chronic Atrial Fibrillation: Comparison by Fractionation of E-wave Deceleration Time into Stiffness and Relaxation Components. | Although the electrophysiologic derangement responsible for atrial fibrillation (AF) has been elucidated, how AF remodels the ventricular chamber and affects diastolic function (DF) has not been fully characterized. The previously validated Parametrized Diastolic Filling (PDF) formalism models suction-initiated filling kinematically and generates error-minimized fits to E-wave contours using unique load (x<sub>o</sub>), relaxation (c), and stiffness (k) parameters. It predicts that E-wave deceleration time (DT) is a function of both stiffness and relaxation. Ascribing DT<sub>s</sub> to stiffness and DTr to relaxation such that DT=DT<sub>s</sub>+DT<sub>r</sub> is legitimate because of causality and their predicted and observed high correlation (r=0.82 and r=0.94) with simultaneous (diastatic) chamber stiffness (dP/dV) and isovolumic relaxation (tau), respectively. We analyzed simultaneous echocardiography-cardiac catheterization data and compared 16 age matched, chronic AF subjects to 16, normal sinus rhythm (NSR) subjects (650 beats). All subjects had diastatic intervals. Conventional DF parameters (DT, AT, E<sub>peak</sub>, E<sub>dur</sub>, E-VTI, E/E') and E-wave derived PDF parameters (c, k, DT<sub>s</sub>, DT<sub>r</sub>) were compared. Total DT and DT<sub>s</sub>, DT<sub>r</sub> in AF were shorter than in NSR (p<0.005), chamber stiffness, (k) in AF was higher than in NSR (p<0.001). For NSR, 75% of DT was due to stiffness and 25% was due to relaxation whereas for AF 81% of DT was due to stiffness and 19% was due to relaxation (p<0.005). We conclude that compared to NSR, increased chamber stiffness is one measurable consequence of chamber remodeling in chronic, rate controlled AF. A larger fraction of E-wave DT in AF is due to stiffness compared to NSR. By trending individual subjects, this method can elucidate and characterize the beneficial or adverse long-term effects on chamber remodeling due to alternative therapies in terms of chamber stiffness and relaxation. |
11,904 | Ventricular Rate Stabilization In Patients With Permanent Atrial Fibrillation And Single-Chamber Ventricular Pacemaker: RARE-PEARL Study. | <b>Background:</b> In patients with permanent atrial fibrillation (AF) rate irregularity can cause symptoms and impair the pumping function of the heart. Ventricular pacing at a rate close to the mean spontaneous ventricular rate can result in a more stable ventricular rate. Specific algorithms for automatic Ventricular Rate Stabilization (VRS) were designed and implemented in commercially available pacemakers. To assess this dynamic rate control we designed the RARE-PEARL study: prospective, randomized, cross-over, double-blinded. <b>Methods:</b> Patients with permanent AF, symptomatic episodes of brady-tachycardia, left ventricular ejection fraction (LVEF) >40%, NYHA class I/II/III, were eligible for enrolment. Each patient (n = 67) was implanted with a single-chamber VVIR pacemaker (models C20 or T20, Vitatron BV, The Netherlands) equipped with the VRS algorithm. At the end of a four week stabilization period, patients were randomized to VRS algorithm ON or OFF (2 months) and then crossed-over for the second phase (2 months). Primary endpoint was patient's preference. <b>Results:</b> Sixty six patients ended the study: 19 (29%) had no preference; 15 (23%) preferred algorithm OFF, 32 (48%) algorithm ON (p<0.0001, algorithm ON vs OFF). In 58% of patients the algorithm ON caused an increase of ventricular pacing percentage > 10%. The ventricular pacing percentage was 82±10% with algorithm ON vs 59±26% with algorithm OFF (p<0.0001). Symptoms did not differ significantly. <b>Conclusions:</b> The VRS algorithm significantly increases the ventricular pacing percentage in patients with permanent AF. This pacing function is preferred by the majority of patients implanted with a single-chamber VVIR pacemaker. |
11,905 | The Role Of Renin Angiotensin System In Atrial Fibrillation. | Atrial fibrillation (AF) is the most prevalent arrhythmia and its incidence is on the rise. AF causes significant morbidity and mortality leading to rising AF-related health care costs. There is experimental and clinical evidence from animal and human studies that suggests a role for the renin angiotensin system (RAS) in the etiopathogenesis of AF. This review appraises the current understanding of RAS antagonism, using angiotensin converting enzyme inhibitors (ACE-I), angiotensin receptor blockers (ARB) and aldosterone antagonists (AA), for prevention of AF. RAS antagonism has proven to be effective for primary and secondary prevention of AF in subjects with heart failure and left ventricular (LV) dysfunction.However, most of the evidence for the protective effect of RAS antagonism is from clinical trials that had AF as a secondary outcome or from unspecified post-hoc analyses. The evidence for prevention in subjects without heart failure and with normal LV function is not as clear. RAS antagonism, in the absence of concomitant antiarrhythmic therapy, was not shown to reduce post cardioversion AF recurrences. RAS antagonism in subjects undergoing catheter ablation has also been ineffective in preventing AF recurrences. |
11,906 | Endocardial focal activation originating from Purkinje fibers plays a role in the maintenance of long duration ventricular fibrillation. | To determine the role of repetitive endocardial focal activations and Purkinje fibers in the maintenance of long duration ventricular fibrillation (LDVF, VF>1 minute) in canine hearts in vivo.</AbstractText>The study was conducted in electrophysiological laboratory of Shanghai Ruijin hospital from July 2010 to August 2012. A 64-electrode basket was introduced through a carotid artery into the left ventricle (LV) of 11 beagle dogs for global endocardial electrical mapping. In the Lugol's solution group (n=5), the subendocardium was ablated by washing with Lugol's solution. In the control group, (n=6) saline was used for ablation. Before and after saline or Lugol ablation, we determined QRS duration and QT/QTc interval in sinus rhythm (SR). We also measured the activation rates in the first 2 seconds of each minute during 7 minutes of VF for each group. If VF terminated spontaneously in less than 7 minutes, the VF segments used in activation rate analysis were reduced accordingly.</AbstractText>At the beginning of VF there was no difference between the groups in the activation rate. However, after 1 minute of LDVF the Lugol's solution group had significantly slower activation rate than the control group. In the control group, all episodes of LDVF (6/6) were successfully sustained for 7 minutes, while in the Lugol's solution group 4/5 episodes of LDVF spontaneously terminated before 7 minutes (4.8±1.4 minutes) (P=0.015). In the control group, at 5.1±1.3 minutes of LDVF, a successive, highly organized focal LV endocardial activation pattern was observed. During this period, activations partly arose in PF and spread to the working ventricular myocardium. Mapping analysis showed that these events were consistent with repetitive endocardial focal activations. No evidence of similar focal activations was observed in the Lugol's solution group.</AbstractText>Repetitive endocardial focal activations in the LV endocardium may be associated with activation of subendocardial PFs. This mechanism may play an important role in the maintenance of LDVF.</AbstractText> |
11,907 | Continuous ECG monitoring for tracking down atrial fibrillation after stroke: Holter or automated analysis strategy? | Tracking down atrial fibrillation (AF) in the stroke unit is a relevant challenge for the prevention of recurrent AF-related stroke. The optimal terms of use of continuous ECG monitoring (CEM) are unknown. We compared 24-hour routine Holter ECG with two different CEM analysis strategies for AF detection.</AbstractText>We prospectively enrolled consecutive ischemic stroke patients. All AF-naïve patients received CEM during hospitalization. Two methods for reading CEM data were compared: manual analysis using the Holter function (hCEM) and semiautomated analysis using software (aCEM). The McNemar test was used to compare AF detection rates.</AbstractText>Of the 362 patients included, 58 (16.0%) were non-AF-naïve patients and 304 were AF-naïve patients. AF-Naïve patients underwent CEM with a median duration of 5.3 days (3.4-9.7). We detected 22 new AF cases (7.2%) with first-24-hour hCEM, 31 (10.2%) with aCEM, and 42 (13.8%) with hCEM. hCEM and aCEM both significantly increased the AF detection rate compared to first-24-hour hCEM. hCEM detected more new AF cases than aCEM (+3.6%, p = 0.003).</AbstractText>In stroke patients, early and prolonged aCEM and hCEM both increase the AF detection rate compared to first-24-hour hCEM. hCEM gives the best AF detection rate. We suggest that in aCEM, detection based only on the ventricular rhythm analysis explains its lower specificity and sensitivity.</AbstractText>© 2014 S. Karger AG, Basel.</CopyrightInformation> |
11,908 | Atrial fibrosis in a chronic murine model of obstructive sleep apnea: mechanisms and prevention by mesenchymal stem cells. | OSA increases atrial fibrillation (AF) risk and is associated with poor AF treatment outcomes. However, a causal association is not firmly established and the mechanisms involved are poorly understood. The aims of this work were to determine whether chronic obstructive sleep apnea (OSA) induces an atrial pro-arrhythmogenic substrate and to explore whether mesenchymal stem cells (MSC) are able to prevent it in a rat model of OSA.</AbstractText>A custom-made setup was used to mimic recurrent OSA-like airway obstructions in rats. OSA-rats (n = 16) were subjected to 15-second obstructions, 60 apneas/hour, 6 hours/day during 21 consecutive days. Sham rats (n = 14) were placed in the setup but no obstructions were applied. In a second series of rats, MSC were administered to OSA-rats and saline to Sham-rats. Myocardial collagen deposit was evaluated in Picrosirius-red stained samples. mRNA expression of genes involved in collagen turnover, inflammation and oxidative stress were quantified by real time PCR. MMP-2 protein levels were quantified by Western Blot.</AbstractText>A 43% greater interstitial collagen fraction was observed in the atria, but not in the ventricles, of OSA-rats compared to Sham-rats (Sham 8.32 ± 0.46% vs OSA 11.90 ± 0.59%, P < 0.01). Angiotensin-I Converting Enzyme (ACE) and Interleukin 6 (IL-6) expression were significantly increased in both atria, while Matrix Metalloproteinase-2 (MMP-2) expression was decreased. MSC administration blunted OSA-induced atrial fibrosis (Sham + Saline 8.39 ± 0.56% vs OSA + MSC 9.57 ± 0.31%, P = 0.11), as well as changes in MMP-2 and IL-6 expression. Interleukin 1-β (IL-1β) plasma concentration correlated to atrial but not ventricular fibrosis. Notably, a 2.5-fold increase in IL-1β plasma levels was observed in the OSA group, which was prevented in rats receiving MSC.</AbstractText>OSA induces selective atrial fibrosis in a chronic murine model, which can be mediated in part by the systemic and local inflammation and by decreased collagen-degradation. MSCs transplantation prevents atrial fibrosis, suggesting that these stem cells could counterbalance inflammation in OSA.</AbstractText> |
11,909 | Evaluation of the complexity of myocardial activation during ventricular fibrillation. An experimental study. | An experimental model is used to analyze the characteristics of ventricular fibrillation in situations of variable complexity, establishing relationships among the data produced by different methods for analyzing the arrhythmia.</AbstractText>In 27 isolated rabbit heart preparations studied under the action of drugs (propranolol and KB-R7943) or physical procedures (stretching) that produce different degrees of change in the complexity of myocardial activation during ventricular fibrillation, use was made of spectral, morphological, and mapping techniques to process the recordings obtained with epicardial multielectrodes.</AbstractText>The complexity of ventricular fibrillation assessed by mapping techniques was related to the dominant frequency, normalized spectral energy, signal regularity index, and their corresponding coefficients of variation, as well as the area of the regions of interest identified on the basis of these parameters. In the multivariate analysis, we used as independent variables the area of the regions of interest related to the spectral energy and the coefficient of variation of the energy (complexity index=-0.005×area of the spectral energy regions -2.234×coefficient of variation of the energy+1.578; P=.0001; r=0.68).</AbstractText>The spectral and morphological indicators and, independently, those derived from the analysis of normalized energy regions of interest provide a reliable approach to the evaluation of the complexity of ventricular fibrillation as an alternative to complex mapping techniques.</AbstractText>Copyright © 2012 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.</CopyrightInformation> |
11,910 | Distension of the ischemic region predicts increased ventricular fibrillation inducibility following coronary occlusion in swine. | Distension of the ischemic region has been related to an increased incidence of spontaneous ventricular arrhythmias following coronary occlusion. This study analyzed whether regional ischemic distension predicts increased ventricular fibrillation inducibility after coronary occlusion in swine.</AbstractText>In 18 anesthetized, open-chest pigs, the left anterior descending coronary artery was ligated for 60 min. Myocardial segment length in the ischemic region was monitored by means of ultrasonic crystals. Programmed stimulation was applied at baseline and then continuously between 10 and 60 min after coronary occlusion.</AbstractText>Coronary occlusion induced a rapid increase in end-diastolic length in the ischemic region, which reached 109.4% (0.9%) of baseline values 10 min after occlusion (P<.001). On average, 6.6 (0.5) stimulation protocols were completed and 5.4 (0.6) ventricular fibrillation episodes induced between 10 and 60 min of coronary occlusion. Neither baseline serum potassium levels nor the size of the ischemic region were significantly related to ventricular fibrillation inducibility. In contrast, the increase in end-diastolic length 10 min after coronary occlusion was associated directly (r=0.67; P=.002) with the number of induced ventricular fibrillation episodes and inversely (r=-0.55; P=.018) with the number of extrastimuli needed for ventricular fibrillation induction.</AbstractText>Regional ischemic expansion predicts increased ventricular fibrillation inducibility following coronary occlusion. These results highlight the potential influence of mechanical factors, acting not only on the triggers but also on the substrate, in the genesis of malignant ventricular arrhythmias during acute ischemia.</AbstractText>Copyright © 2012 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.</CopyrightInformation> |
11,911 | Update on arrhythmias and cardiac pacing 2013. | This report discusses a selection of the most relevant articles on cardiac arrhythmias and pacing published in 2013. The first section discusses arrhythmias, classified as regular paroxysmal supraventricular tachyarrhythmias, atrial fibrillation, and ventricular arrhythmias, together with their treatment by means of an implantable cardioverter defibrillator. The next section reviews cardiac pacing, subdivided into resynchronization therapy, remote monitoring of implantable devices, and pacemakers. The final section discusses syncope. |
11,912 | Spanish Catheter Ablation Registry. 12th Official Report of the Spanish Society of Cardiology Working Group on Electrophysiology and Arrhythmias (2012). | This article presents the findings of the 2012 Spanish Catheter Ablation Registry.</AbstractText>Data were collected in 2 ways: retrospectively using a standardized questionnaire, and prospectively using a central database. Each participating center selected its own preferred method of data collection.</AbstractText>Seventy-four Spanish centers voluntarily contributed data to the survey. A total of 11 042 ablation procedures were analyzed, averaging 149 (103) per center. The 3 main conditions treated were atrioventricular nodal reentrant tachycardia (n=2842; 25.7%), cavotricuspid isthmus (n=2485; 23%), and accessory pathways (n=1999; 18%). Atrial fibrillation was the fourth most common substrate treated (n=1852; 17%), representing a slight increase. The number of ventricular arrhythmia ablation procedures was similar to that of 2011, but there was a decrease in procedures for ventricular tachycardia associated with postinfarction scarring. The overall success rate was 94.9%, major complications occurred in 1.9%, and the overall mortality rate was 0.04%.</AbstractText>Data from the 2012 registry show that the number of ablations performed continued to increase. Overall, they also show a high success rate and a low number of complications. Ablation of complex substrates continued to increase, particularly in the case of atrial fibrillation.</AbstractText>Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.</CopyrightInformation> |
11,913 | Exome sequencing helped the fine diagnosis of two siblings afflicted with atypical Timothy syndrome (TS2). | Long-QT syndrome (LQTS) causes a prolongation of the QT-interval in the ECG leading to life threatening tachyarrhythmia and ventricular fibrillation. One atypical form of LQTS, Timothy syndrome (TS), is associated with syndactyly, immune deficiency, cognitive and neurological abnormalities as well as distinct cranio-facial abnormalities.</AbstractText>On a family with both children diagnosed with clinical LQTS, we performed whole exome sequencing to comprehensively screen for causative mutations after a targeted candidate gene panel screen for Long-QT syndrome target genes failed to identify any underlying genetic defect. Using exome sequencing, we identified in both affected children, a p.402G > S mutation in exon 8 of the CACNA1C gene, a voltage-dependent Ca2+ channel. The mutation was inherited from their father, a mosaic mutation carrier. Based on this molecular finding and further more careful clinical examination, we refined the diagnosis to be Timothy syndrome (TS2) and thereby were able to present new therapeutic approaches.</AbstractText>Our study highlights the difficulties in accurate diagnosis of patients with rare diseases, especially those with atypical clinical manifestation. Such challenge could be addressed with the help of comprehensive and unbiased mutation screening, such as exome sequencing.</AbstractText> |
11,914 | A prospective clinical study of myocarditis in cases of acute ingestion of paraphenylene diamine (hair dye) poisoning in northern India. | Myocarditis is a unheard and unreported dangerous complication of hair dye ingestion which contains paraphenylene diamine. So a prospective study was planned to assess myocardial damage in regard to clinical profile and outcome with different treatment approaches in patients with oral ingestion of Hair dye.</AbstractText>The material comprised of 1595 cases admitted in Medicine Department of Maharani Laxmi Bai Medical College, Jhansi, Uttar Pradesh-INDIA, from July 2004 to Jan 2011. Out of 1595 cases 1060 cases were of stone hair dye poisoning and 535 cases were of other branded hair dyes (powdered form containing less amount of Paraphenylene diamine). Diagnosis of myocarditis was made solely on the basis of the clinical signs/symptoms suggestive of myocardial damage, electrocardiography changes, elevated cardiac biomarkers and abnormalities on trans thoracic echocardiography. The cases were thoroughly studied for cardiac complications. Myocarditis was reported in 15% of total cases with mortality rate of 29%. Occurrence of myocarditis was directly related to amount of Hair dye ingested. In patients affected from myocarditis 9% develop life threatening Ventricular tachycardia/ventricular fibrillation.</AbstractText>Hair dye (Paraphenylene di amine) is highly toxic. In cases who consumed more than 10 gram of Paraphenylene diamine, myocarditis is a dangerous complication. Proper management includes continuous cardiac monitoring to prevent sudden cardiac death.</AbstractText> |
11,915 | Cardiac electrophysiological alterations in heart/muscle-specific manganese-superoxide dismutase-deficient mice: prevention by a dietary antioxidant polyphenol. | Cardiac electrophysiological alterations induced by chronic exposure to reactive oxygen species and protective effects of dietary antioxidant have not been thoroughly examined. We recorded surface electrocardiograms (ECG) and evaluated cellular electrophysiological abnormalities in enzymatically-dissociated left ventricular (LV) myocytes in heart/muscle-specific manganese-superoxide dismutase-deficient (H/M-Sod2(-/-)) mice, which exhibit dilated cardiomyopathy due to increased oxidative stress. We also investigated the influences of intake of apple polyphenols (AP) containing mainly procyanidins with potent antioxidant activity. The QRS and QT intervals of ECG recorded in H/M-Sod2(-/-) mice were prolonged. The effective refractory period in the LV myocardium of H/M-Sod2(-/-) mice was prolonged, and susceptibility to ventricular tachycardia or fibrillation induced by rapid ventricular pacing was increased. Action potential duration in H/M-Sod2(-/-) LV myocytes was prolonged, and automaticity was enhanced. The density of the inwardly rectifier K(+) current (I K1) was decreased in the LV cells of H/M-Sod2(-/-) mice. The AP intake partially improved these electrophysiological alterations and extended the lifespan in H/M-Sod2(-/-) mice. Thus, chronic exposure of the heart to oxidative stress produces a variety of electrophysiological abnormalities, increased susceptibility to ventricular arrhythmias, and action potential changes associated with the reduced density of I K1. Dietary intake of antioxidant nutrients may prevent oxidative stress-induced electrophysiological disturbances. |
11,916 | Atrial antitachycardia pacing and managed ventricular pacing in bradycardia patients with paroxysmal or persistent atrial tachyarrhythmias: the MINERVA randomized multicentre international trial. | Atrial fibrillation (AF) is a common comorbidity in bradycardia patients. Advanced pacemakers feature atrial preventive pacing and atrial antitachycardia pacing (DDDRP) and managed ventricular pacing (MVP), which minimizes unnecessary right ventricular pacing. We evaluated whether DDDRP and MVP might reduce mortality, morbidity, or progression to permanent AF when compared with standard dual-chamber pacing (Control DDDR).</AbstractText>In a randomized, parallel, single-blind, multi-centre trial we enrolled 1300 patients with bradycardia and previous atrial tachyarrhythmias, in whom a DDDRP pacemaker had recently been implanted. History of permanent AF and third-degree atrioventricular block were exclusion criteria. After a 1-month run-in period, 1166 eligible patients, aged 74 ± 9 years, 50% females, were randomized to Control DDDR, DDDRP + MVP, or MVP. Analysis was intention-to-treat. The primary outcome, i.e. the 2-year incidence of a combined endpoint composed of death, cardiovascular hospitalizations, or permanent AF, occurred in 102/385 (26.5%) Control DDDR patients, in 76/383 (19.8%) DDDRP + MVP patients [hazard ratio (HR) = 0.74, 95% confidence interval 0.55-0.99, P = 0.04 vs. Control DDDR] and in 85/398 (21.4%) MVP patients (HR = 0.89, 95% confidence interval 0.77-1.03, P = 0.125 vs. Control DDDR). When compared with Control DDDR, DDDRP + MVP reduced the risk for AF longer than 1 day (HR = 0.66, 95% CI 0.52-0.85, P < 0.001), AF longer than 7 days (HR = 0.52, 95% CI 0.36-0.73, P < 0.001), and permanent AF (HR = 0.39, 95% CI 0.21-0.75, P = 0.004).</AbstractText>In patients with bradycardia and atrial tachyarrhythmias, DDDRP + MVP is superior to standard dual-chamber pacing. The primary endpoint was significantly lowered through the reduction of the progression of atrial tachyarrhythmias to permanent AF.</AbstractText>NCT00262119.</AbstractText>© The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.</CopyrightInformation> |
11,917 | Prevalence and prognostic value of concealed structural abnormalities in patients with apparently idiopathic ventricular arrhythmias of left versus right ventricular origin: a magnetic resonance imaging study. | Routine diagnostic work-up occasionally does not identify any abnormality among patients with monomorphic ventricular arrhythmias (VAs) of left ventricular (LV) origin. Aim of this study was to investigate the value of cardiac MRI (cMRI) for the diagnostic work-up and prognostication of these patients.</AbstractText>Forty-six consecutive patients (65% males; mean age, 44±15 years) with monomorphic VAs of LV origin and negative routine diagnostic work-up were included. Seventy-four consecutive patients (60% males; mean age, 40±17 years) with apparently idiopathic monomorphic VAs of right ventricular origin served as control group. Both groups underwent comprehensive cMRI study and were followed-up for a median of 14 months (25th-75th percentiles, 7-37 months). The outcome event was an arrhythmic composite end point of sudden cardiac death or nonfatal episode of ventricular fibrillation or sustained ventricular tachycardia requiring external cardioversion or appropriate implantable cardioverter defibrillator therapy. The 2 groups of patients did not differ in age (P=0.14) and sex (P=0.57). No significant difference was observed between patients with VAs of LV origin and VAs of right ventricular origin about biventricular volumes and systolic function. cMRI demonstrated myocardial structural abnormalities in 19 (41%) patients with VAs of LV origin versus 4 (5%) patients with VAs of right ventricular origin (P<0.001). The outcome event occurred in 9 patients; myocardial structural abnormalities on cMRI were significantly related to the outcome event (hazard ratio, 41.6; 95% confidence interval, 5.2-225.0; P<0.001).</AbstractText>Myocardial structural changes are detected by cMRI in a non-negligible proportion of patients with apparently idiopathic monomorphic VAs of LV origin and are associated with worse outcome.</AbstractText>© 2014 American Heart Association, Inc.</CopyrightInformation> |
11,918 | Relationship between autoantibody to the angiotensin II-1 receptor and cardiovascular manifestations of Graves' disease. | To investigate the role of autoantibody against angiotensin II-1 receptor (AT1-AA) in patients with cardiovascular manifestations of Graves' disease (GD).</AbstractText>The epitope of the second extracellular loop of AT1 receptor (165-191) was synthesized and used as antigens to screen the autoantibody by enzyme linked immunosorbent assay (ELISA). The patients with GD were divided into the patients with cardiovascular manifestations associated to GD (Group A, n=58) and the patients with GD not complicated by heart disease (Group B, n=60). 40 healthy subjects were included in the study (Group C, n=40). Echocardiography was performed and the differences of echocardiography parameters were compared between AT1-AA positive and negative groups in group A. Factors related to left heart enlargement were analyzed by multiple logistic regression.</AbstractText>(1) The frequency of AT1-AA in Group A (52.2%, 32/58) were significantly higher than those in Group B (16.7%, 10/60) and Group C (12.5%, 5/40) (all p<0.001). (2) There were no differences in the level of TGAb, TPOAb and TRAb between AT1-AA positive and negative groups in patients with GD (all p>0.05). (3) In patients with cardiovascular manifestations of GD, the ratios between left atrial and ventricular enlargement (LAE and LVE) were significantly higher in the AT1-AA positive group than in the AT1-AA negative group (68.8% vs. 26.9%, 62.5% vs. 23.1%, all p<0.01); the frequency of atrial fibrillation differed significantly between these 2 groups (53.1% vs. 19.2%, p<0.01). (4) Regression analysis demonstrated that the positive AT1-AA and course of GD were significantly correlated to the presence of LAE and LVE.</AbstractText>AT1-AA plays an important role in the pathogenesis of cardiovascular manifestations associated to GD. Especially, AT1-AA is involved in left cardiac dilatation of GD complicated by heart disease, which represents a cardio-vascular risk factor for GD patients.</AbstractText>© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.</CopyrightInformation> |
11,919 | Myotonic dystrophy type 1 mimics and exacerbates Brugada phenotype induced by Nav1.5 sodium channel loss-of-function mutation. | Myotonic dystrophy type 1 (DM1), a muscular dystrophy due to CTG expansion in the DMPK gene, can cause cardiac conduction disorders and sudden death. These cardiac manifestations are similar to those observed in loss-of-function SCN5A mutations, which are also responsible for Brugada syndrome (BrS).</AbstractText>The purpose of this study was to investigate DM1 effects on clinical expression of a loss-of-function SCN5A mutation causing BrS.</AbstractText>We performed complete clinical evaluation, including ajmaline test, in 1 family combining DM1 and BrS. We screened the known BrS susceptibility genes. We characterized an SCN5A mutation using whole-cell patch-clamp experiments associated with cell surface biotinylation.</AbstractText>The proband, a 15-year-old female, was a survivor of out-of-hospital cardiac arrest with ventricular fibrillation. She combined a DMPK CTG expansion from the father's side and an SCN5A mutation (S910L) from the mother's side. S910L is a trafficking defective mutant inducing a dominant negative effect when transfected with wild-type Nav1.5. This loss-of-function SCN5A mutation caused a Brugada phenotype during the mother's ajmaline test. Surprisingly, in the father, a DM1 patient without SCN5A mutation, ajmaline also unmasked a Brugada phenotype. Furthermore, association of both genetic abnormalities in the proband exacerbated the response to ajmaline with a massive conduction defect.</AbstractText>Our study is the first to describe the deleterious effect of DM1 on clinical expression of a loss-of-function SCN5A mutation and to show a provoked BrS phenotype in a DM1 patient. The modification of the ECG pattern by ajmaline supports the hypothesis of a link between DM1 and Nav1.5 loss of -function.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,920 | Epicardial linear electroporation ablation and lesion size. | Electroporation can be used as a nonthermal method to ablate myocardial tissue. However, like with all electrical ablation methods, determination of the energy supplied into the myocardium enhances the clinically required controllability over lesion creation.</AbstractText>To investigate the relationship between the magnitude of epicardial electroporation ablation and the lesion size using an electrically isolating linear suction device.</AbstractText>In 5 pigs (60-75 kg), the pericardium was opened after medial sternotomy. A custom linear suction device with a single 35 × 6-mm electrode inside a 42-mm-long and 7-mm-wide plastic suction cup was used for electroporation ablation. Single cathodal applications of 30, 100, or 300 J were delivered randomly at 3 different epicardial left ventricular sites. Coronary angiography was performed before ablation, immediately after ablation, and after 3 months survival. Lesion size was measured histologically after euthanization.</AbstractText>The mean depth of 30, 100, and 300 J lesions was 3.2 ± 0.7, 6.3 ± 1.8, and 8.0 ± 1.5 mm, respectively (P = .0003). The mean width of 30, 100, and 300 J lesions was 10.1 ± 0.8, 15.1 ± 1.5, and 17.1 ± 1.3 mm, respectively (P<.0001). Significant tissue shrinkage was observed at the higher energy levels. No luminal arterial narrowing was observed after 3 months: 2.3 ± 0.3 mm vs 2.3 ± 0.4 mm (P = .85).</AbstractText>The relationship between the amount of electroporation energy delivered through a linear suction device with a single linear electrode and the mean myocardial lesion size is significant in the absence of major adverse events or permanent damage to the coronary arteries.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,921 | The ratio of early mitral inflow velocity to global diastolic strain rate as a useful predictor of cardiac outcomes in patients with atrial fibrillation. | Although the ratio of early mitral inflow velocity (E) to global diastolic strain rate (E'sr) has been correlated with left ventricular filling pressure, its relationship with cardiac outcomes in patients with atrial fibrillation (AF) has never been evaluated. The aim of this study was to examine the ability of E/E'sr ratio in predicting cardiac outcomes in patients with AF.</AbstractText>In 190 patients with persistent AF, comprehensive echocardiography was performed, with assessment of E'sr from three standard apical views using the index beat method. Cardiac events were defined as death and hospitalization for heart failure.</AbstractText>There were 50 cardiac events, including 22 deaths and 28 hospitalizations for heart failure, during an average follow-up period of 20 months (interquartile range, 14-32 months). Multivariate analysis showed old age, chronic heart failure, and increased E/E'sr ratio (per 10-cm E/E'sr increase; hazard ratio, 1.258; 95% confidence interval, 1.132-1.398, P < .001) were associated with increased cardiac events. In direct comparison, E/E'sr ratio outperformed the ratio of E to early diastolic mitral annular velocity (E') in predicting adverse cardiac events in both univariate and multivariate models (P ≤ .046). Additionally, the addition of E/E'sr ratio to a clinical model including age, chronic heart failure, diabetes, hypertension, left atrial volume index, left ventricular ejection fraction, and E/E' still provided an extra benefit in the prediction of adverse cardiac events (P = .010).</AbstractText>E/E'sr ratio is a useful parameter and is stronger than E/E' ratio in predicting adverse cardiac events, and it may offer additional prognostic benefit over conventional clinical and echocardiographic parameters in patients with AF.</AbstractText>Copyright © 2014 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
11,922 | Left atrial strain provides incremental value for embolism risk stratification over CHA₂DS₂-VASc score and indicates prognostic impact in patients with atrial fibrillation. | The aim of this study was to investigate whether left atrial (LA) strain has incremental value over the CHA2DS2-VASc score for stratifying the risk for embolism in patients with atrial fibrillation (AF) and whether LA strain predicts poststroke mortality.</AbstractText>Consecutive patients with paroxysmal or persistent AF with acute embolism (82 patients) or without (204 controls) were prospectively enrolled. Global peak LA longitudinal strain during ventricular systole (LAS) was assessed during AF rhythm. Global LAS was compared between the groups in the first cross-sectional study. Then, the 82 patients with acute embolism were prospectively followed during the second prospective cohort study.</AbstractText>Global LAS was lower in patients with acute embolism than in controls (P < .001). Global LAS < 15.4% differentiated patients with acute embolism from controls, with an area under the curve of 0.83 (P < .0001). In multivariate analysis, global LAS was independently associated with acute embolism (odds ratio, 0.74; 95% confidence interval, 0.67-0.82; P < .001) and had an incremental value over the CHA2DS2-VASc score (P < .0001). Furthermore, 26 patients with acute embolisms died during a median follow-up period of 425 days. Global LAS independently predicted mortality after embolism.</AbstractText>In this observational study, LA strain provided incremental diagnostic information over that provided by the CHA2DS2-VASc score, suggesting that LA strain analysis could improve the current risk stratification of embolism in patients with AF. LA strain can also predict poststroke mortality.</AbstractText>Copyright © 2014 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
11,923 | Resuscitation Outcomes Consortium-Amiodarone, Lidocaine or Placebo Study (ROC-ALPS): Rationale and methodology behind an out-of-hospital cardiac arrest antiarrhythmic drug trial. | Despite their wide use, whether antiarrhythmic drugs improve survival after out-of-hospital cardiac arrest (OHCA) is not known. The ROC-ALPS is evaluating the effectiveness of these drugs for OHCA due to shock-refractory ventricular fibrillation or pulseless ventricular tachycardia (VF/VT).</AbstractText>ALPS will randomize 3,000 adults across North America with nontraumatic OHCA, persistent or recurring VF/VT after ≥1 shock, and established vascular access to receive up to 450 mg amiodarone, 180 mg lidocaine, or placebo in the field using a double-blind protocol, along with standard resuscitation measures. The designated target population is all eligible randomized recipients of any dose of ALPS drug whose initial OHCA rhythm was VF/VT. A safety analysis includes all randomized patients regardless of their eligibility, initial arrhythmia, or actual receipt of ALPS drug. The primary outcome of ALPS is survival to hospital discharge; a secondary outcome is functional survival at discharge assessed as a modified Rankin Scale score ≤3.</AbstractText>The principal aim of ALPS is to determine if survival is improved by amiodarone compared with placebo; secondary aim is to determine if survival is improved by lidocaine vs placebo and/or by amiodarone vs lidocaine. Prioritizing comparisons in this manner acknowledges where differences in outcome are most expected based on existing knowledge. Each aim also represents a clinically relevant comparison between treatments that is worth investigating.</AbstractText>Results from ALPS will provide important information about the choice and value of antiarrhythmic therapies for VF/VT arrest with direct implications for resuscitation guidelines and clinical practice.</AbstractText>Copyright © 2014 Mosby, Inc. All rights reserved.</CopyrightInformation> |
11,924 | Comparison between ivabradine and low-dose digoxin in the therapy of diastolic heart failure with preserved left ventricular systolic function. | Multicenter trials have demonstrated that in patients with sinus rhythm ivabradine is effective in the therapy of ischemic heart disease and of impaired left ventricular systolic function. Ivabradine is ineffective in atrial fibrillation. Many patients with symptomatic heart failure have diastolic dysfunction with preserved left ventricular systolic function, and many have asymptomatic paroxysmal atrial fibrillation. Ivabradine is not indicated in these conditions, but it happens that it is erroneously used. Digoxin is now considered an outdated and potentially dangerous drug and while effective in the mentioned conditions, is rarely used. The aim of the study was to compare the therapeutic effects of ivabradine in diastolic heart failure with preserved left ventricular systolic function. Patients were assigned to ivabradine or digoxin according to a randomization cross-over design. Data were single-blind analyzed. The analysis was performed using an intention-to-treat method. Forty-two coronary patients were selected. In spite of maximally tolerated therapy with renin-antagonists, diuretics and β-blockers, they had congestive diastolic heart failure with preserved systolic function. Both ivabradine and digoxin had positive effects on dyspnea, Nterminal natriuretic peptide, heart rate, duration of 6-min. walk-test and signs of diastolic dysfunction, but digoxin was high-statistically more effective. Side-effects were irrelevant. Data were obtained in a single-center and from 42 patients with ischemic etiology of heart failure. The number of patients is small and does not allow assessing mortality. In coronary patients with symptomatic diastolic heart failure with preserved systolic function low-dose digoxin was significantly more effective than ivabradine and is much cheaper. One should be more critical about ivabradine and low-dose digoxin in diastolic heart failure. To avoid possible negative effects on the cardiac function and a severe reduction of the cardiac output the resting heart rate should not be decreased to <65 beats/min. |
11,925 | Clinical characteristics and treatment outcomes of patients with Brugada syndrome in northeastern Thailand. | Brugada syndrome (BrS) is a common genetic cause of sudden cardiac arrest (SCA) due to polymorphic ventricular tachycardia and ventricular fibrillation. The current recommended therapy for high-risk BrS patients is the use of an implantable cardioverter defibrillator (ICD). The present study aimed to report the clinical characteristics and treatment outcomes of BrS patients in northeastern Thailand.</AbstractText>Patients who were diagnosed with BrS or had a Brugada electrocardiogram (ECG) between 2005 and 2012 at Khon Kaen University's hospitals were enrolled in the present study. Patients' clinical characteristics, ECG type, laboratory results and treatment were reviewed.</AbstractText>A total of 90 eligible patients were enrolled. Of these, 79 (87.8%) patients were symptomatic--65 (82.3%) had documented SCA and 14 (17.7%) had unexplained syncope. The remaining 11 (12.2%) patients were asymptomatic with Brugada ECG. A majority of the patients enrolled were born in northeastern Thailand. The mean age of the symptomatic patients was 44.49 ± 8.55 years. Among the symptomatic patients, a majority were male (n = 77, 97.5%) and 23 (29.1%) patients had a family history of SCA. Almost all BrS patients who were symptomatic (96.2%) received ICD treatment for secondary prevention. The number of patients who received appropriate ICD therapy was 4.2 times of those who received inappropriate shocks. Only 3 (3.8%) symptomatic BrS patients refused ICD treatment.</AbstractText>Clinical characteristics did not distinguish between symptomatic BrS patients and asymptomatic patients with Brugada ECGs. The clinical characteristics and treatment outcomes for the symptomatic BrS patients with SCA and unexplained syncope were similar. Among the BrS patients implanted with secondary prevention ICD in Northeastern Thailand, nearly one-third had received appropriate ICD therapy, far exceeding the incidence of device-related complications and inappropriate therapy.</AbstractText> |
11,926 | Resuscitated cardiac arrest and prognosis following myocardial infarction. | To determine whether resuscitated cardiac arrest (CA) complicating ST elevation myocardial infarction (STEMI) impacts outcome, particularly in patients surviving to discharge.</AbstractText>Resuscitated CA complicating STEMI is associated with increased inpatient mortality. The impact on later prognosis is unclear.</AbstractText>We analysed data from the UK Myocardial Ischaemia National Audit Project for STEMI patients admitted during January 2008-March 2010. We used survival analyses to assess the independent impact of resuscitated CA during the index episode on inhospital, 30 days, 1 year and medium term all-cause mortality.</AbstractText>Of 48 749 STEMI patients, 5308 (10.9%) were recorded as having a CA. Of these, 1557 (29.3%) died on the day of CA. In survivors, after covariate adjustment, resuscitated CA was associated with increased risk of death during the index admission (HR 4.05 (3.69 to 4.45) p<0.001). In patients surviving to discharge, a history of resuscitated CA was associated with increased risk of death to 30 days (HR 1.53 (1.18 to 2.00), p<0.001). However, beyond 30 days, resuscitated CA was not associated with increased mortality risk (1-year HR 0.95 (0.79 to 1.14, p=0.596); 3.5 years HR 0.90 (0.78 to 1.04), p=0.144). The influence of resuscitated CA on inhospital or 30-day mortality was similar whether CA occurred before or after hospital admission. Where the resuscitated CA rhythm was asystole, inhospital mortality was higher compared with ventricular arrhythmia (p<0.001) or pulseless electrical activity (p=0.011). Late resuscitated CA (occurring after the day of index STEMI) was associated with higher 30-day postdischarge mortality compared with early resuscitated CA (p=0.023).</AbstractText>STEMI complicated by resuscitated CA merits careful monitoring in the early period postevent. In contemporary practice, there is no impact of resuscitated CA on longer-term prognosis.</AbstractText>Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.</CopyrightInformation> |
11,927 | The clinical profile and pathophysiology of atrial fibrillation: relationships among clinical features, epidemiology, and mechanisms. | Atrial fibrillation (AF) is the most common arrhythmia (estimated lifetime risk, 22%-26%). The aim of this article is to review the clinical epidemiological features of AF and to relate them to underlying mechanisms. Long-established risk factors for AF include aging, male sex, hypertension, valve disease, left ventricular dysfunction, obesity, and alcohol consumption. Emerging risk factors include prehypertension, increased pulse pressure, obstructive sleep apnea, high-level physical training, diastolic dysfunction, predisposing gene variants, hypertrophic cardiomyopathy, and congenital heart disease. Potential risk factors are coronary artery disease, kidney disease, systemic inflammation, pericardial fat, and tobacco use. AF has substantial population health consequences, including impaired quality of life, increased hospitalization rates, stroke occurrence, and increased medical costs. The pathophysiology of AF centers around 4 general types of disturbances that promote ectopic firing and reentrant mechanisms, and include the following: (1) ion channel dysfunction, (2) Ca(2+)-handling abnormalities, (3) structural remodeling, and (4) autonomic neural dysregulation. Aging, hypertension, valve disease, heart failure, myocardial infarction, obesity, smoking, diabetes mellitus, thyroid dysfunction, and endurance exercise training all cause structural remodeling. Heart failure and prior atrial infarction also cause Ca(2+)-handling abnormalities that lead to focal ectopic firing via delayed afterdepolarizations/triggered activity. Neural dysregulation is central to atrial arrhythmogenesis associated with endurance exercise training and occlusive coronary artery disease. Monogenic causes of AF typically promote the arrhythmia via ion channel dysfunction, but the mechanisms of the more common polygenic risk factors are still poorly understood and under intense investigation. Better recognition of the clinical epidemiology of AF, as well as an improved appreciation of the underlying mechanisms, is needed to develop improved methods for AF prevention and management. |
11,928 | Protection from outpatient sudden cardiac death following ICD removal using a wearable cardioverter defibrillator. | An implantable cardioverter defibrillator (ICD) is effective in preventing sudden cardiac death (SCD). Once an ICD is removed and reimplantation is not feasible, a wearable cardioverter defibrillator (WCD) may be an alternative option. We determined the effectiveness of WCD for SCD prevention in patients who were discharged after ICD removal.</AbstractText>A retrospective study was conducted on all WCD (LifeVest, ZOLL, Pittsburgh, PA, USA) patients who underwent ICD removal due to cardiac device infections (CDIs) at two referral centers between January 1, 2005 and December 31, 2009. Clinical characteristics, device information, and WCD data were analyzed. Sudden cardiac arrest was defined as all sustained ventricular tachycardia (VT) and ventricular fibrillation occurring within a single 24-hour period.</AbstractText>Ninety-seven patients (mean age 62.8 ± 13.3, male 80.4%) were included in the study. The median duration of antibiotic use was 14.7 days (interquartile range [IQR] 10-30). The median daily WCD use was 20 hours/day and the median length of use was 21 days (IQR 5-47). A total of three patients were shocked by WCD. Two patients had four episodes of sustained VT, successfully terminated by the WCD. A third patient experienced two inappropriate treatments due to oversensitivity of the signal artifact. Three patients experienced sudden death outside the hospital while not wearing the device. Five patients died while hospitalized.</AbstractText>WCD can prevent SCD, until ICD reimplantation is feasible in patients who underwent device removals for CDI. However, patient compliance is essential for the effective use of this device.</AbstractText>©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
11,929 | Incomplete cure of tachycardia-induced cardiomyopathy secondary to rapid atrial fibrillation by heart rate control without sinus conversion. | It is uncertain whether rate or rhythm control is more favorable for patients experiencing tachycardia-induced cardiomyopathy (TIC) secondary to rapid atrial fibrillation (AF).</AbstractText>We compared the electrophysiological and hemodynamic properties and outcome after AF ablation in 20 patients with a history of decompensated TIC who maintained sinus rhythm or had paroxysmal AF (group 1), 32 with a history of decompensated TIC who had persistent or longstanding persistent AF (group 2), 377 without TIC who had paroxysmal AF (group 3), and 225 without TIC who had persistent or longstanding persistent AF (group 4). The corrected sinus node recovery time was more prolonged in group 2 than in groups 1, 3, or 4 (1,066 ± 946 vs. 416 ± 188, 450 ± 322 and 590 ± 329 milliseconds; P < 0.001, respectively). The mean left atrial pressure in group 2 was greater than that in groups 1, 3, or 4 (13.9 ± 6.5 vs. 7.5 ± 3.1, 8.2 ± 4.1 and 10.8 ± 4.2 mmHg; P < 0.001, respectively). The left ventricular ejection fraction assessed after the recovery from the decompensation was more decreased in group 2 than in group 1; however, it almost returned to normal if sinus rhythm was maintained after the AF ablation in group 2. The presence of a history of TIC did not predict an AF recurrence after the ablation.</AbstractText>Heart rate control during AF without sinus conversion may result in an incomplete cure of TIC, suggesting the advantages of rhythm control with ablation in patients with TIC.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,930 | Renal dysfunction and clinical outcomes of patients undergoing ICD and CRTD implantation: data from the Israeli ICD registry. | Implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT) reduce mortality in patients with heart failure (HF) and left ventricular dysfunction. However, their efficacy in patients with chronic kidney disease (CKD) is controversial.</AbstractText>We examined the association between renal dysfunction and clinical outcomes in patients undergoing ICD and CRT defibrillator (CRTD) implantation.</AbstractText>Data were collected from the Israeli ICD registry. Estimated glomerular filtration rate (eGFR) at implantation was assessed using the modification of diet in renal disease formula. Primary outcome was all-cause mortality. Secondary outcomes included the composite endpoints of death or HF and death or ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation [VT/VF]); any hospitalizations; first appropriate and inappropriate ICD therapy.</AbstractText>During the study period (July 2010-November 2012), 2,811 patients were implanted with ICD or CRTD. One-year follow-up data were available for 730 ICD patients and 453 CRTD patients. Patients with eGFR < 30 mL/minute/1.73 m(2) (n = 54, 4.6%) were older, had a higher prevalence of diabetes, hypertension, or ischemic heart disease. eGFR <30 mL/minute/1.73 m(2) was associated with increased mortality risk in ICD (HR 5.4; 95% CI 1.5-19.2), but not in CRTD patients (HR 0.9; 95% CI 0.1-7.5). Renal dysfunction was associated with the composite endpoints of death or HF and death or VT/VF in ICD, but not in CRTD patients. Mean eGFR during follow-up decreased by 8.0 ± 4.3 mL/minute/1.73 m(2) in ICD patients (P = 0.06) and by 1.8 ± 1.3 mL/minute/1.73 m(2) in patients with CRTD (P = 0.2).</AbstractText>Based on this retrospective analysis, CKD is associated with adverse prognosis after ICD implantation, but not after CRTD implantation. GFR decreased in patients with ICD, but not in CRTD patients.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,931 | Time-domain T-wave alternans is strongly associated with a history of ventricular fibrillation in patients with Brugada syndrome. | T-wave alternans (TWA) is an indicator of vulnerability to ventricular arrhythmias and is useful for predicting sudden cardiac death (SCD) in patients with various structural heart diseases. We evaluated whether high levels of time-domain TWA on ambulatory ECG (AECG) are associated with a history of ventricular fibrillation (VF) in Brugada syndrome (BrS) patients.</AbstractText>We examined the associations among VF history, family history of SCD, spontaneous type 1 electrocardiogram (ECG), late potentials, VF induction by programmed electrical stimulation, and TWA in 45 BrS patients (44 males; mean age, 45 ± 15 years). TWA analyzed from 24-h AECG recordings using the modified moving average method was positive in 13 of 43 patients (30%). Patients with a history of VF had a significantly higher incidence of a positive TWA test (82% vs. 13%; P < 0.001) and spontaneous type 1 ECG (92% vs. 38%; P = 0.007) than those without VF history. Multivariate analysis indicated that positive TWA (OR 7.217; 95% CI 2.503-35.504; P = 0.002) and spontaneous type 1 ECG (OR 5.530; 95% CI 1.651-34.337; P = 0.020) were closely associated with VF history. Spontaneous type 1 ECG had high sensitivity (92%) but low specificity (63%). Positive TWA was a reliable marker with high sensitivity and specificity (82% and 88%, respectively).</AbstractText>Elevated time-domain TWA on AECG confirms arrhythmia risk in symptomatic BrS patients without the need for provocative stimuli.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,932 | Pathophysiology, prevention, and treatment of commotio cordis. | Commotio cordis is increasing described and it is now clear that this phenomenon is an important cause of sudden cardiac death on the playing field. Victims are predominantly young, male, and struck in the left chest with a ball. An animal model has been developed and utilized to explore the important variables and mechanism of commotio cordis. Impact during a narrow window of repolarization causes ventricular fibrillation. Other important variables include location, velocity, shape, and hardness of the impact object. Biological characteristics such as gender, pliability of the chest wall, and genetic susceptibility also play a role in commotio cordis. The mechanism of ventricular fibrillation appears to be an increase in heterogeneity of repolarization caused by induced abnormalities of ion channels activated by abrupt increases in left ventricular pressure. In the setting of altered repolarization a trigger of ventricular depolarization (premature ventricular depolarization caused directly by the chest blow) initiates a spiral wave that quickly breaks down into ventricular fibrillation. Prevention of commotio cordis is possible. Improved recognition and resuscitation have led to an improvement in outcome. |
11,933 | A shocking past: a walk through generations of defibrillation development. | Defibrillation is one of the most successful and widely recognized applications of electrotherapy. Yet the historical road to its first successful application in a patient and the innovative adaptation to an implantable device is marred with unexpected turns, political and personal setbacks, and public and scientific condemnation at each new idea. Driven by dedicated scientists and ever-advancing creative applications of new technologies, from electrocardiography to high density mapping and computational simulations, the field of defibrillation persevered and continued to evolve to the life-saving tool it is today. In addition to critical technological advances, the history of defibrillation is also marked by the plasticity of the theory of defibrillation. The advancing theories of success have propelled the campaign for reducing the defibrillation energy requirement, instilling hope in the development of a painless and harmless electrical defibrillation strategy. |
11,934 | Valsartan improves the electrophysiological characteristics of left ventricular hypertrophic myocardium in spontaneously hypertensive rats. | The objective was to investigate the effects of valsartan on the electrophysiological characteristics of left ventricular hypertrophic myocardium in spontaneously hypertensive rats (SHR). A total of 24 10-week-old male SHR were divided into two groups: valsartan and non-valsartan groups (n=12 in each). Twelve 10-week-old Wistar-Kyoto rats were served as the control group. Kv4.2 expression was measured in left ventricular myocardium using western blots. In addition, the systolic blood pressure, left ventricular mass index (LVMI), ventricular effective refractory period and ventricular fibrillation threshold (VFT) were also measured after eight weeks. INa, ICaL, Ito and membrane capacitance were measured in left ventricular myocytes after 8 weeks by whole-cell patch clamp. Valsartan decreased LVMI compared with the non-Valsartan group (Valsartan vs. non-Valsartan: 3.2±0.03 mg g(-1) vs. 3.7±0.02 mg g(-1), P<0.01). Valsartan also enhanced the VFT compared with the non-Valsartan group (Valsartan vs. non-Valsartan: 18.6±0.3 mA vs. 15.4±0.4 mA, P<0.01). The expression of Kv4.2 was significantly lower in the non-Valsartan and Valsartan groups compared with the control group (P<0.01). The expression of Kv4.2 was significantly higher in the Valsartan group compared with the non-Valsartan group (P<0.01). Valsartan decreased the density of ICaL compared with non-Valsartan group (Valsartan vs. non-Valsartan: -5.5±0.6 pA/pF vs. -7.2±0.9 pA/pF, P<0.05). Valsartan improved the density of Ito compared with non-Valsartan group(Valsartan vs. non-Valsartan: 13.93±0.8 pA/pF vs. 11.22±1.0 pA/pF, P<0.05). Valsartan improves the electrophysiological characteristics of left ventricular hypertrophic myocardium in spontaneously hypertensive rat. |
11,935 | Catheter ablation related mitral valve injury: the importance of early recognition and rescue mitral valve repair. | An increasing number of catheter ablations involve the mitral annular region and valve apparatus, increasing the risk of catheter interaction with the mitral valve (MV) complex. We review our experience with catheter ablation-related MV injury resulting in severe mitral regurgitation (MR) to delineate mechanisms of injury and outcomes.</AbstractText>We searched the Mayo Clinic MV surgical database over a 19-year period (1993-2012) and the electrophysiologic procedures database over a 23-year period (1990-2013) and identified 9 patients with catheter ablation related MV injury requiring clinical intervention.</AbstractText>Indications for ablation included atrial fibrillation (AF) [n = 4], ventricular tachycardia (VT) [n = 3], and left-sided accessory pathways [n = 2]. In all 4 AF patients, a circular mapping catheter entrapped in the MV apparatus was responsible for severe MR. In all 3 VT patients, radiofrequency energy delivery led to direct injury to the MV apparatus. In the 2 patients with accessory pathways, both mechanisms were involved (1 per patient). Six patients required surgical intervention (5 MV repair, 1 catheter removal). One patient developed severe functional MR upon successful endovascular catheter disentanglement that improved spontaneously. Two VT patients with persistent severe postablation MR were managed nonsurgically, 1 of whom died 3 months postprocedure.</AbstractText>Circular mapping catheter entrapment and ablation at the mitral annulus are the most common etiologies of MV injury during catheter ablation. Close surveillance of the MV is needed during such procedures and early surgical repair is important for successful salvage if significant injury occurs.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,936 | Compatibility of electroanatomical mapping systems with a concurrent percutaneous axial flow ventricular assist device. | Hemodynamic instability hinders activation and entrainment mapping during ventricular tachycardia ablation. The Impella 2.5 microaxial flow device (MFD; Abiomed Inc., Danvers, MA, USA) is used to prevent hemodynamic instability during electrophysiologic study. However, electromagnetic interference (EMI) generated by this device can preclude accurate electroanatomic mapping.</AbstractText>Impella was placed in the left ventricle of 7 canines for circulatory support. Electroanatomic mapping during sinus rhythm, ventricular pacing, and ventricular fibrillation (VF) was performed using magnet- (CARTO3, Biosense Webster Inc., Diamond Bar, CA, USA) and impedance- (EnSite Velocity System/EnSite NavX, St. Jude Medical Inc., St. Paul, MN, USA) based systems. Distance from device to points with severe EMI precluding acquisition was compared to points with mild/no EMI. Two methods were used to reduce EMI: (1) titration of MFD performance, and (2) impedance-only mapping combined with manual annotation of activation.</AbstractText>Severe EMI did not occur during impedance-based mapping. Severe EMI was observed using CARTO3 at 9.4% of all points attempted at maximum performance level (P8) of device. Severe EMI occurred at points closer to device (40.1 ± 16.8 mm) versus (55.5 ± 20.0 mm) for mild/no EMI, P < 0.0001. Severe EMI using CARTO3 was resolved by either (1) reduction of performance from P8 to P6 or (2) impedance-only mapping with manual annotation.</AbstractText>Concurrent use of MFD caused EMI to prevent acquisition of points with magnet-based mapping. Predictors for EMI were distance from device and performance level. Temporary reductions to P6 or impedance-only mapping are 2 methods to resolve EMI.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,937 | A comparative study on the effect of amiodarone and metaprolol for prevention of arrythmias after open heart surgery. | The aim of this study was to compare the effect of amiodarone and metaprolol in prevention of atrial fibrillation in patients, following open heart surgery.</AbstractText>This prospective study was carried out between May 2008 to Nov. 2010, and comprised a total of 50 patients with normal preoperative sinus rhythm undergoing open heart surgery using cardio pulmonary bypass.</AbstractText>Mean age of patients was 47+2.7 years, of which 60% who developed atrial fibrillation aged from 51 to 60 years. Most patients (62%) were in NYHA Class III. Patients who received amiodarone showed significant improvement in LVEF compared to those treated with Metaprolol. Amiodarone treated group exhibited lesser incidence and short-lasting atrial fibrillation, lower ventricular rate, shorter hospitalization, and lesser cost of care than those in metaprolol group.</AbstractText>The present study showed that amiodarone was more efficient in controlling post-operative atrial fibrillation as compared to metaprolol. However, a larger randomized controlled trial is needed to corroborate the result of this study.</AbstractText> |
11,938 | Very long-term durability of the edge-to-edge repair for isolated anterior mitral leaflet prolapse: up to 21 years of clinical and echocardiographic results. | To assess the very long-term clinical and echocardiographic results of the edge-to-edge repair for mitral regurgitation (MR) due to isolated prolapse or flail of the anterior leaflet.</AbstractText>From 1991 to 2004, 139 patients (age, 54±14.4 years; left ventricular ejection fraction 56%±7.8%, New York Heart Association class I-II in 68.9%, atrial fibrillation in 20.1%) with severe degenerative MR due to isolated segmental prolapse or flail of the anterior leaflet were treated with the EE technique combined with annuloplasty. MR had resulted from prolapse or flail of the central scallop of the anterior leaflet (A2) in 105 patients (75.5%) and scallops A1 or A3 in 34 (24.4%).</AbstractText>No hospital deaths occurred. At hospital discharge, MR was absent or mild in 130 patients (93.5%) and moderate (2+/4+) in 9 (6.4%). The clinical and echocardiographic follow-up data were 97.1% complete (mean length, 11.5±3.73 years; median, 11; longest duration, 21.5). At 17 years, the actuarial survival was 72.4%±7.89%, freedom from cardiac death was 90.8%±4.77%, and freedom from reoperation was 89.6%±2.74%. At the last echocardiographic examination, recurrence of MR grade≥3+ was documented in 17 patients (17 of 135, 12.5%). Freedom from MR grade≥3+ at 17 years was 80.2%±5.86%. At multivariate analysis, the predictors of MR recurrence grade≥3+ were residual MR greater than mild at hospital discharge (hazard ratio, 7.4; 95% confidence interval, 2.5-21.2; P=.0001) and the use of posterior pericardial rather than prosthetic ring annuloplasty, which was very close to statistical significance (hazard ratio, 2.8; 95% confidence interval, 0.9-8.7; P=.06).</AbstractText>In patients with MR due to segmental anterior leaflet prolapse, the very long-term results of the edge-to-edge repair combined with annuloplasty were excellent.</AbstractText>Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,939 | Outcomes of out-of-hospital cardiac arrest by public location in the public-access defibrillation era. | The strategy to place public-access automated external defibrillators (AEDs) has not yet been established in real settings.</AbstractText>This, prospective, population-based observational study in Osaka, Japan, included consecutive out-of-hospital cardiac arrest (OHCA) patients with resuscitation attempts during 7 years, from January 2005 through December 2011. The trends in the proportion of public-access AED use and 1-month survival with neurologically favorable outcome were evaluated by location. Factors associated with neurologically favorable outcome (defined as cerebral performance category 1 or 2) after ventricular fibrillation were also assessed using multiple logistic regression analysis. A total of 9453 bystander-witnessed OHCAs of cardiac origin were documented and 894 (9.5%) of them occurred at public places. The proportion of public-access AED use significantly increased from 0.0% (0/20) in 2005 to 41.2% (7/17) in 2011 at railway stations and from 0.0% (0/7) to 56.5% (13/23) at sports facilities. Mean time from collapse to shock was 5.0 minutes among those who received shocks with public-access AEDs. The proportion of neurologically favorable outcome was 28.0% (33/118) at railway stations, 51.6% (48/93) at sports facilities, 23.3% (20/86) in public buildings, and 41.9% (13/31) in schools. In multivariate analysis, early defibrillation, irrespective of bystander or emergency medical service (EMS) personnel, was significantly associated with neurologically favorable outcome (adjusted odds ratio for 1-minute increment, 0.89; 95% confidence interval, 0.87 to 0.92).</AbstractText>This large, population-based OHCA registry demonstrated that earlier shock, irrespective the shock provider (bystander or EMS personnel), contributed to improving outcome, and a public-access defibrillation program was successfully implemented so that shocks with public-access AEDs were delivered to over 40% of bystander-witnessed OHCAs and time to shock was shortened in some kinds of public places.</AbstractText> |
11,940 | Atrial arrhythmias after lung transplant: underlying mechanisms, risk factors, and prognosis. | Atrial arrhythmias (AAs) early after lung transplant are frequent and have a significant impact on morbidity and mortality. However, the pathogenesis of AAs after lung transplant remains incompletely understood. In this study we aimed to determine the prevalence of atrial fibrillation (AF) and other AAs, as well as risk factors, clinical outcomes and possible underlying mechanisms associated with AAs after lung transplant.</AbstractText>A retrospective analysis was performed on 382 patients who underwent lung transplantation from 2000 to 2010. A 12-lead electrocardiogram (ECG) was obtained and AAs classified as AF and other AAs (atrial flutter [AFL] and supraventricular tachycardia [SVT]). Multivariate logistic regression analysis was performed to determine predictors, and Kaplan-Meier survival curves were constructed.</AbstractText>The incidence of AAs was 25%; 17.8% developed AF and 7.6% other AAs (AFL/SVT). The major indication for transplant was idiopathic pulmonary fibrosis (IPF, 35%). Significant predictors of AF were as follows: age; IPF; left atrial enlargement; diastolic dysfunction; and history of coronary artery disease (CAD). Risk factors for other AAs (AFL/SVT) were: age; right ventricle dysfunction; right ventricular enlargement; and elevated right atrial pressure (RAP). One-year mortality was higher in the arrhythmia group (21.5% arrhythmia vs 15.7% no-arrhythmia group; p < 0.05). In addition, patients treated with anti-arrhythmic medications had higher mortality (p < 0.05).</AbstractText>AAs are common after lung transplantation. Risk factors for developing either AF or other AAs (AFL/SVT) are different. The development of early AAs post-transplant is associated with prolonged post-operative stay and increased mortality. A rate-control strategy should be used as first-line therapy and anti-arrhythmic agents reserved for those patients who do not respond to the initial treatment.</AbstractText>Copyright © 2014 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,941 | Main complications of mild induced hypothermia after cardiac arrest: a review article. | The aim of the present study is to assess the complications of mild induced hypothermia (MIH) in patients with cardiac arrest. Presently, based on the guidelines of the American heart Association, MIH following successful cardiopulmonary resuscitation (CPR) in unconscious adult patients due to ventricular fibrillation (VF) with out-of-hospital cardiac arrest (OOHCA) is essential and required. However, MIH could be associated with complications in Patients with cardiac arrest. Studies conducted on the precautions and care following cardiac arrest and MIH were included. Valid scientific data bases were used for data collection. The obtained results from different studies revealed that mild MIH could be associated with numerous complications and the knowledge and awareness of the medical staff from the complications is required to guarantee successful therapeutic approaches in MIH following cardiac arrest which is a novel medical facility with different styles and complications. Overall, further future studies are required to improve the quality of MIH, to increase survival and to decrease complications rates. |
11,942 | Adrenaline, terlipressin, and corticoids versus adrenaline in the treatment of experimental pediatric asphyxial cardiac arrest. | To analyze if treatment with adrenaline (epinephrine) plus terlipressin plus corticoids achieves higher return of spontaneous circulation than adrenaline in an experimental infant animal model of asphyxial cardiac arrest.</AbstractText>Prospective randomized animal study.</AbstractText>Experimental department in a University Hospital.</AbstractText>Forty-nine piglets were studied.</AbstractText>Cardiac arrest was induced by at least 10 minutes of removal of mechanical ventilation and was followed by manual external chest compressions and mechanical ventilation. After 3 minutes of resuscitation, piglets that did not achieve return of spontaneous circulation were randomized to two groups: adrenaline 0.02 mg kg every 3 minutes (20 animals) and adrenaline 0.02 mg kg every 3 minutes plus terlipressin 20 μg kg every 6 minutes plus hydrocortisone 30 mg kg one dose (22 animals). Resuscitation was discontinued when return of spontaneous circulation was achieved or after 24 minutes.</AbstractText>Return of spontaneous circulation was achieved in 14 piglets (28.5%), 14.2% with only cardiac massage and ventilation. Return of spontaneous circulation was achieved in 25% of piglets treated with adrenaline and in 9.1% of those treated with adrenaline plus terlipressin plus hydrocortisone (p = 0.167). Return of spontaneous circulation was achieved in 45.4% of animals with pulseless electric activity, 20% with asystole, and 0% with ventricular fibrillation (p = 0.037). Shorter duration of cardiac arrest, higher mean blood pressure and EtCO2 and lower PaCO2 before resuscitation, and higher mean blood pressure during resuscitation were associated with higher return of spontaneous circulation.</AbstractText>Treatment with adrenaline plus terlipressin plus corticoids does not achieve higher return of spontaneous circulation than that with adrenaline in an infant animal model of asphyxial cardiac arrest.</AbstractText> |
11,943 | Cardiac resynchronization therapy: who benefits? | Cardiac resynchronization therapy (CRT) has been well established in multiple large trials to improve symptoms, hospitalizations, reverse remodeling, and mortality in well-selected patients with heart failure when used in addition to optimal medical therapy. Updated consensus guidelines outline patients in whom such therapy is most likely to result in substantial benefit. However, pooled data have demonstrated that only approximately 70% of patients who qualify for CRT based on current indications actually respond favorably. In addition, current guidelines are based on outcomes from the carefully selected patients enrolled in clinical trials, and almost certainly fail to include all patients who might benefit from CRT.</AbstractText>The identification of patients most likely to benefit from CRT requires consideration of factors beyond these standard criteria, QRS morphology with particular consideration in patients with left bundle-branch block pattern, extent of QRS prolongation, etiology of cardiomyopathy, rhythm, and whether the patient requires or will eventually need antibradycardia pacing. In addition, the baseline severity of functional impairment may influence the type of benefit to be expected from CRT; for example, New York Heart Association class I patients may derive long-term benefit in cardiac structure and function, but no benefit in symptoms or hospitalizations can be reasonably expected. In contrast, certain New York Heart Association class IV patients may be too sick to realize long-term mortality benefits from CRT, but improvements in hemodynamic profile and functional capacity may represent vital advances in this population.</AbstractText>This review evaluates the evidence regarding the various factors that can predict positive or even detrimental responses to CRT, to help better determine who benefits most from this evolving therapy.</AbstractText>Copyright © 2014 Icahn School of Medicine at Mount Sinai. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,944 | Management of hypertrophic cardiomyopathy. | Hypertrophic cardiomyopathy (HCM) is clinically defined as unexplained myocardial hypertrophy, and it is an autosomal dominant disease of the cardiac sarcomere. It is present in 1 in 500 in the general adult population, making it the most common genetic cardiovascular disease. The pathophysiology of HCM is complex, leading to significant variability in clinical presentation. This, combined with the lack of randomized trials, makes the management of these patients difficult.</AbstractText>The majority of patients with HCM are asymptomatic without a substantial reduction in survival. However, a considerable portion of patients will experience significant symptoms and HCM-related death, and effective therapies are available for these patients. Patients may have symptoms of heart failure from outflow tract obstruction and/or restrictive physiology. Medical therapy targeted at the underlying pathophysiology should be used, and surgical myectomy or alcohol septal ablation is available for those with refractory symptoms. While the overall risk of sudden cardiac death (SCD) is low in HCM patients, some are at elevated risk for and experience SCD, a devastating outcome in young patients. Risk stratification for SCD and treatment with implantable cardioverter-defibrillators is paramount. Many HCM patients will also develop atrial fibrillation, and this is often poorly tolerated. A rhythm control strategy with antiarrhythmic drugs or catheter ablation is often necessary, and anticoagulation should be administered to reduce the risk of thromboembolism. Finally, family members of patients with HCM should be regularly screened with electrocardiography and echocardiography.</AbstractText>HCM is a complex disease with heterogeneous phenotypes and clinical manifestations. The management of HCM focuses on reducing symptoms of heart failure, preventing SCD, treating atrial fibrillation, and screening family members. Treatment should be tailored to the unique characteristics of each individual patient.</AbstractText>Copyright © 2014 Icahn School of Medicine at Mount Sinai. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,945 | Therapeutic hypothermia after in-hospital cardiac arrest: a critique. | More than 210,000 in-hospital cardiac arrests occur annually in the United States. Use of moderate therapeutic hypothermia (TH) in comatose survivors after return of spontaneous circulation following out-of-hospital cardiac arrest (OOH-CA) caused by ventricular fibrillation or pulseless ventricular tachycardia is recommended strongly by many professional organizations and societies. The use of TH after cardiac arrest associated with nonshockable rhythms and after in-hospital cardiac arrest (IH-CA) is recommended to be considered by these same organizations and is being applied widely. The use in these latter circumstances is based on an extrapolation of the data supporting its use after out-of-hospital cardiac arrest associated with shockable rhythms. The purpose of this article is to review the limitations of existing data supporting these extended application of TH after cardiac arrest and to suggest approaches to this dilemma. The data supporting its use for OOH-CA appear to this author, and to some others, to be rather weak, and the data supporting the use of TH for IH-CA appear to be even weaker and to include no randomized controlled trials (RCTs) or supportive observational studies. The many reasons why TH might be expected to be less effective following IH-CA are reviewed. The degree of neurologic injury may be more severe in many of these cases and, thus, may not be responsive to TH as currently practiced following OOH-CA. The potential adverse consequences of the routine use of TH for IH-CA are listed and include complications associated with TH, interference with diagnostic and interventional therapy, and use of scarce personnel and financial resources. Most importantly, it inhibits the ability of researchers to conduct needed RCTs. The author believes that the proper method of providing TH in these cases needs to be better defined. Based on this analysis the author concludes that TH should not be used indiscriminantly following most cases of IH-CA, and instead clinicians should concentrate their efforts in conducting high-quality large RCTs or large-scale, well-designed prospective observation studies to determine its benefits and identify appropriate candidates. |
11,946 | Heptanol decreases the incidence of ischemia-induced ventricular arrhythmias through altering electrophysiological properties and connexin 43 in rat hearts. | Heptanol is a type of gap junction inhibitor that decreases electrical conduction velocity. However, little is known regarding the effects of heptanol on the arrhythmias induced by regional myocardial ischemia. This study aimed to investigate the effects of heptanol on ventricular arrhythmias and the underlying mechanisms. On the Langendorff apparatus, isolated hearts of Sprague-Dawley rats underwent 30 min of ischemia, with or without pretreatment with heptanol (0.1, 0.3 or 0.5 mM), 15 min prior to the induction of regional ischemia through ligation of the left anterior descending coronary artery. The incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) were recorded after ligation. Heptanol decreased the incidence of ventricular arrhythmias (45% in the control group vs. 10% in the 0.1 mM group, 0% in the 0.3 mM group and 0% in the 0.5 mM group, P<0.05), whereas it prolonged the PR interval, QT interval and monophasic action potential duration at 90% repolarization (MAPD90). As evaluated with immunofluorescence microscopy, heptanol was able to partly reverse the downregulation of connexin 43 (Cx43) induced by ischemia. The results of the reverse transcription-polymerase chain reaction were consistent with those of immunofluorescence. In conclusion, heptanol significantly decreased the incidence of VT and VF induced by regional ischemia and prolonged the PR interval, QT interval and MAPD90. Heptanol also partly reversed the downregulation of Cx43 induced by ischemia. |
11,947 | Successful percutaneous coronary intervention during cardiac arrest with use of an automated chest compression device: a case report. | Ventricular tachycardia or fibrillation (VT/VF) in patients with ST-elevation myocardial infarction (STEMI) is associated with poor prognosis. Performing manual chest compressions is a serious obstacle for treatment with percutaneous coronary intervention (PCI). Here we introduce a case with refractory VT/VF where the patient was successfully treated with an automated chest compression device, which made revascularization with PCI possible. |
11,948 | Incidence and outcome of in-hospital cardiac arrest in the United Kingdom National Cardiac Arrest Audit. | To report the incidence, characteristics and outcome of adult in-hospital cardiac arrest in the United Kingdom (UK) National Cardiac Arrest Audit database.</AbstractText>A prospectively defined analysis of the UK National Cardiac Arrest Audit (NCAA) database. 144 acute hospitals contributed data relating to 22,628 patients aged 16 years or over receiving chest compressions and/or defibrillation and attended by a hospital-based resuscitation team in response to a 2222 call. The main outcome measures were incidence of adult in-hospital cardiac arrest and survival to hospital discharge.</AbstractText>The overall incidence of adult in-hospital cardiac arrest was 1.6 per 1000 hospital admissions with a median across hospitals of 1.5 (interquartile range 1.2-2.2). Incidence varied seasonally, peaking in winter. Overall unadjusted survival to hospital discharge was 18.4%. The presenting rhythm was shockable (ventricular fibrillation or pulseless ventricular tachycardia) in 16.9% and non-shockable (asystole or pulseless electrical activity) in 72.3%; rates of survival to hospital discharge associated with these rhythms were 49.0% and 10.5%, respectively, but varied substantially across hospitals.</AbstractText>These first results from the NCAA database describing the current incidence and outcome of adult in-hospital cardiac arrest in UK hospitals will serve as a benchmark from which to assess the future impact of changes in service delivery, organisation and treatment for in-hospital cardiac arrest.</AbstractText>Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
11,949 | Sleep-disordered breathing increases the risk of arrhythmias. | Sleep-disordered breathing (SDB) has been consistently associated with increased risk for cardiovascular diseases, including arrhythmias. The purpose of this review is to elucidate the several pathophysiologic pathways such as repetitive hypoxia and reoxygenation, increased oxidative stress, inflammation and sympathetic activation that may underlie the increased incidence of arrhythmias in SDB patients. We discuss in particular the incidence of ventricular arrhythmias, atrial fibrillation and bradyarrhythmias in SDB patients. In addition, we discuss the electrocardiographic alteration such as ST-T changes during apneic events and QT dispersion induced by SDB that may trigger complex ventricular arrhythmias and sudden cardiac death. Finally, we consider also the therapeutic interventions such as continuous positive airways pressure therapy, a standard treatment for SDB, that may reduce the incidence and recurrence of supraventricular and ventricular arrhythmias in patients with SDB. |
11,950 | From Clinical Misdiagnosis to Electrophysiological Diagnosis: Two Male Asystole Cases. | Differential diagnosis of epilepsy and syncope may be difficult. Arrhythmias such as asystole, or ventricular fibrillation, may lead to cerebral hypoperfusion mimicking partial or secondary generalized tonic-clonic seizures. While performing an electroencephalogram (EEG) for epilepsy diagnosis, simultaneous electrocardiogram (ECG) recording may detect cardiac pathology. In this article, through 2 cases, who had cardiac asystole during the EEG, we demonstrate the importance of ECG during EEG. To rule out cardiac pathology in syncope cases, all necessary investigations must be done. |
11,951 | [Aortic and mitral valve replacement via right thoracotomy in the case of a patient with severe heart failure following right pneumonectomy]. | We report a case of aortic valve replacement (AVR) and mitral valve replacement (MVR) in a patient with severe left ventricular dysfunction who had undergone right pneumonectomy for lung cancer 14 years previously. A 64-year-old man had cathecolamine-dependent heart failure due to bicuspid aortic valve stenosis, functional mitral valve regurgitation and impaired left ventricular function (left ventricular ejection fraction 13%)because of dilated cardiomyopathy. AVR and MVR were performed using St. Jude Medical mechanical valves with right thoracotomy because the heart had shifted to the right side. Poor left ventricular function and postoperative atrial fibrillation made it difficult to control low-output syndrome, but prolonged use of intra-aortic balloon pumping improved it gradually. Intraaortic balloon pumping( IABP) was removed 34 days after the operation, the respirator was removed with tracheotomy 63 days postoperatively, and the patient was discharged on the 177th postoperative day. Careful preoperative assessment and perioperative control of heart failure are important components of successful clinical management. |
11,952 | Evaluation of dronedarone as a therapeutic option for patients with atrial fibrillation. | Atrial fibrillation (AF) is the predominant dysrhythmia affecting approximately 2·4 million people in the United States and over 6 million Europeans. Dronedarone is a benzofuran derivative of amiodarone newly approved in 2009 for the treatment of AF. Here, we comment on the efficacy and safety of dronedarone in patients with AF.</AbstractText>Eight randomized controlled trials were analysed in this article. Several trials showed that dronedarone therapy delayed AF recurrence, controlled ventricular rate and reduced incidences of hospitalization or death. However, some of the studies were terminated early due to an excess mortality rate. Further studies on long-term safety and trials on direct comparison to rate controlling medications are suggested to obtain additional insight of dronedarone.</AbstractText>Dronedarone reduces the incidence of AF recurrences, hospitalization and death in patients with paroxysmal or persistent AF. However, dronedarone should not be used in high-risk patients with permanent AF or patients with unstable chronic heart failure (HF) due to safety concerns.</AbstractText> |
11,953 | The role of late I Na in development of cardiac arrhythmias. | Late I Na is an integral part of the sodium current, which persists long after the fast-inactivating component. The magnitude of the late I Na is relatively small in all species and in all types of cardiomyocytes as compared with the amplitude of the fast sodium current, but it contributes significantly to the shape and duration of the action potential. This late component had been shown to increase in several acquired or congenital conditions, including hypoxia, oxidative stress, and heart failure, or due to mutations in SCN5A, which encodes the α-subunit of the sodium channel, as well as in channel-interacting proteins, including multiple β subunits and anchoring proteins. Patients with enhanced late I Na exhibit the type-3 long QT syndrome (LQT3) characterized by high propensity for the life-threatening ventricular arrhythmias, such as Torsade de Pointes (TdP), as well as for atrial fibrillation. There are several distinct mechanisms of arrhythmogenesis due to abnormal late I Na, including abnormal automaticity, early and delayed after depolarization-induced triggered activity, and dramatic increase of ventricular dispersion of repolarization. Many local anesthetic and antiarrhythmic agents have a higher potency to block late I Na as compared with fast I Na. Several novel compounds, including ranolazine, GS-458967, and F15845, appear to be the most selective inhibitors of cardiac late I Na reported to date. Selective inhibition of late I Na is expected to be an effective strategy for correcting these acquired and congenital channelopathies. |
11,954 | Editor's perspective: Atrioventricular nodal reentry tachycardia: chameleon in disguise. | Hayashi et al teach us a sequential approach to question the possibilities that explain observed unusual phenomena and demonstrate the importance of finding a reasonable ablation target that is safe although the explanation of all phenomenon is incomplete. Perhaps future developments of mapping systems and novel signal processing presently meant for identifying atrial fibrillation and ventricular fibrillation substrate may allow us to record nodal and perinodal electrograms to better understand these complex arrhythmias in individual patients. |
11,955 | Assessing the performance of the Framingham Stroke Risk Score in the reasons for geographic and racial differences in stroke cohort. | The most well-known stroke risk score is the Framingham Stroke Risk Score (FSRS), which was developed during the higher stroke risk period of the 1990s and has not been validated for blacks. We assessed the performance of the FSRS among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study to determine whether it is useful in both blacks and whites.</AbstractText>Expected annualized stroke rates from the FSRS were compared with observed stroke rates overall and within strata defined by FSRS risk factors (age, sex, systolic blood pressure, use of antihypertensive medications, diabetes mellitus, smoking, atrial fibrillation, left ventricular hypertrophy, and prevalent coronary heart disease).</AbstractText>Among 27 748 participants stroke-free at baseline, 715 stroke events occurred over 5.6 years of follow-up. FSRS-estimated incidence rates of stroke were 1.6× higher than observed for black men, 1.9× higher for white men, 1.7× higher for black women, and 1.7× higher for white women. This overestimation was consistent among most subgroups of FSRS factors, although the magnitude of overestimation varied by the risk factor assessed.</AbstractText>Although higher FSRS was associated with higher stroke risk, the FSRS overestimated the observed stroke rates in this study, particularly in certain subgroups. This may be because of temporal declines in stroke rates, secular trends in prevention treatments, or differences in populations studied. More accurate estimates of event rates are critical for planning research, including clinical trials, and targeting health-care efforts.</AbstractText>© 2014 American Heart Association, Inc.</CopyrightInformation> |
11,956 | Re-examining outcomes after unsuccessful out-of-hospital resuscitation in the era of field termination of resuscitation guidelines and regionalized post-resuscitation care. | Dismal prognosis after failed out-of-hospital resuscitation has previously been demonstrated. Changes in resuscitation and post-resuscitation care may affect patient outcomes. We describe characteristics and outcomes of patients with out-of-hospital cardiac arrest (OOHCA) transported to specialty cardiac centers after failure of out-of-hospital interventions.</AbstractText>In Los Angeles (LA) County, patients with non-traumatic OOHCA with return of spontaneous circulation (ROSC) are transported to specialized cardiac care centers. Outcomes are reported to a registry maintained by the LA County Emergency Medical Services (EMS) Agency. We report patient characteristics and outcomes for the subset of patients treated at these specialty centers in whom initial ROSC was achieved in the ED. The primary outcome was neurologically intact survival, defined by a cerebral performance category (CPC) score of 1 or 2.</AbstractText>105 patients transported to the SRC after failure to achieve ROSC with out-of-hospital resuscitation were successfully resuscitated in the ED. The median age was 68 years (IQR 57-78); 74 (70%) were male. The presenting rhythm was ventricular fibrillation or ventricular tachycardia in 40 patients (38%) and 86 (82%) were witnessed. Twenty-two patients (21%) survived to hospital discharge. Of the 103 patients with known CPC scores, 13 (13% [95% CI 7-21%]) survived to hospital discharge with a CPC score of 1 or 2. No patient who survived with good neurologic outcome met criteria for termination of resuscitation in the field.</AbstractText>Failure of out-of-hospital resuscitation is not universally predictive of poor neurologic outcome.</AbstractText>Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
11,957 | Differential Release Kinetics of Cardiac Biomarkers in Patients Undergoing Valve Replacement Surgery. | Differential release kinetics of cardiac biomarkers including brain natriuretic peptide (BNP), Troponin-I, and CK-MB following valve replacement (VR) are not well characterized.</AbstractText>We serially measured these biomarkers 24 hours prior, six hours, 24 hours, 48 hours, and one month following mitral/aortic VR in 100 patients. Baseline BNP, Tn-I, and CK-MB levels were 304.01 pg/mL, 0.03 ng/mL, and 0.99 ng/mL, respectively. While BNP levels decreased at six hours, and then peaked at 24 hours, Tn-I and CK-MB levels increased within six hours and then showed declining trends by 24 hours. While Tn-I and CK-MB levels normalized at one month, 33% patients still had BNP >200 pg/mL. Those with baseline BNP >200 pg/mL more commonly had AF, higher RV systolic pressure, longer inotrope and ventilator duration, and longer mean ICU/hospital stay as compared to those with lower BNP, although echocardiographic left ventricular ejection fraction and Tn-I/CK-MB levels were similar. Inotrope duration >42 hours, ventilation time >29 hours, and ICU stay >4 days was seen in 42% versus 19%, 30% versus 9%, and 33% versus 14%, respectively, in those with BNP >/<200 pg/mL. Baseline BNP had a significant positive correlation with mean inotrope duration, ICU, and hospital stay. Baseline BNP was also a significant predictor of inotrope duration (odds ratio [OR]=5.9, 95% confidence interval [CI]=1.20-29.68, p=0.01) and ventilation time (OR=4.7, 95% CI=1.76-17.21, p=0.02).</AbstractText>Release kinetics of cardiac biomarkers is significantly different following VR; BNP levels increase following an initial transient decline. Only BNP was a predictor of postoperative variables.</AbstractText> |
11,958 | Efficacy of chest compressions directed by end-tidal CO2 feedback in a pediatric resuscitation model of basic life support. | End-tidal carbon dioxide (ETCO2) correlates with systemic blood flow and resuscitation rate during cardiopulmonary resuscitation (CPR) and may potentially direct chest compression performance. We compared ETCO2-directed chest compressions with chest compressions optimized to pediatric basic life support guidelines in an infant swine model to determine the effect on rate of return of spontaneous circulation (ROSC).</AbstractText>Forty 2-kg piglets underwent general anesthesia, tracheostomy, placement of vascular catheters, ventricular fibrillation, and 90 seconds of no-flow before receiving 10 or 12 minutes of pediatric basic life support. In the optimized group, chest compressions were optimized by marker, video, and verbal feedback to obtain American Heart Association-recommended depth and rate. In the ETCO2-directed group, compression depth, rate, and hand position were modified to obtain a maximal ETCO2 without video or verbal feedback. After the interval of pediatric basic life support, external defibrillation and intravenous epinephrine were administered for another 10 minutes of CPR or until ROSC. Mean ETCO2 at 10 minutes of CPR was 22.7±7.8 mm Hg in the optimized group (n=20) and 28.5±7.0 mm Hg in the ETCO2-directed group (n=20; P=0.02). Despite higher ETCO2 and mean arterial pressure in the latter group, ROSC rates were similar: 13 of 20 (65%; optimized) and 14 of 20 (70%; ETCO2 directed). The best predictor of ROSC was systemic perfusion pressure. Defibrillation attempts, epinephrine doses required, and CPR-related injuries were similar between groups.</AbstractText>The use of ETCO2-directed chest compressions is a novel guided approach to resuscitation that can be as effective as standard CPR optimized with marker, video, and verbal feedback.</AbstractText> |
11,959 | Troponin elevation after radiofrequency catheter ablation of atrial fibrillation: relevance to AF substrate, procedural outcomes, and reverse structural remodeling. | Although radiofrequency ablation creates myocardial necrosis leading to troponin T (TnT) release into the systemic circulation, the significance of TnT elevation after atrial fibrillation (AF) ablation is unknown.</AbstractText>To demonstrate a possible mechanism of reverse structural remodeling in the left atrium (LA) by evaluating postprocedural TnT elevation.</AbstractText>This study included 106 patients with an enlarged LA (paroxysmal AF, n = 43; persistent AF, n = 63). All patients underwent pulmonary vein isolation alone in the index procedure. Left atrial volume indexed to body surface area (LAVi) was measured by echocardiography before ablation and 6 months after sinus rhythm restoration. Patients were divided into responders (n = 53) and nonresponders (n = 53) based on a cutoff value of 23% reduction in LAVi. The TnT level was measured 12 hours postprocedure.</AbstractText>LAVi decreased from 43 ± 13 to 33 ± 12 mL/m(2) (P < .0001). The TnT level was higher in responders than in nonresponders (1.31 ± 0.34 μg/L vs 0.88 ± 0.29 μg/L; P < .0001) and correlated linearly with percent reduction in LAVi (R = .54; P < .0001). Also in multivariate analysis, the TnT level was the only independent predictor for responders (odds ratio 90.1; 95% confidence interval 14.95-543.3; P < .0001). The TnT level in patients who required a repeat procedure (n = 30) was lower than that in patients who did not require a repeat procedure only in the persistent AF group (0.92 ± 0.38 μg/L vs 1.16 ± 0.37 μg/L; P = .01).</AbstractText>Greater elevation of the TnT level was related both to favorable outcomes after ablation and to greater reversal of structural remodeling. Postprocedural TnT level may be reflective of the preservation of healthy LA myocardium.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,960 | Collaborative virtual reality based advanced cardiac life support training simulator using virtual reality principles. | Advanced Cardiac Life Support (ACLS) is a series of team-based, sequential and time constrained interventions, requiring effective communication and coordination of activities that are performed by the care provider team on a patient undergoing cardiac arrest or respiratory failure. The state-of-the-art ACLS training is conducted in a face-to-face environment under expert supervision and suffers from several drawbacks including conflicting care provider schedules and high cost of training equipment.</AbstractText>The major objective of the study is to describe, including the design, implementation, and evaluation of a novel approach of delivering ACLS training to care providers using the proposed virtual reality simulator that can overcome the challenges and drawbacks imposed by the traditional face-to-face training method.</AbstractText>We compare the efficacy and performance outcomes associated with traditional ACLS training with the proposed novel approach of using a virtual reality (VR) based ACLS training simulator. One hundred and forty-eight (148) ACLS certified clinicians, translating into 26 care provider teams, were enrolled for this study. Each team was randomly assigned to one of the three treatment groups: control (traditional ACLS training), persuasive (VR ACLS training with comprehensive feedback components), or minimally persuasive (VR ACLS training with limited feedback components). The teams were tested across two different ACLS procedures that vary in the degree of task complexity: ventricular fibrillation or tachycardia (VFib/VTach) and pulseless electric activity (PEA).</AbstractText>The difference in performance between control and persuasive groups was not statistically significant (P=.37 for PEA and P=.1 for VFib/VTach). However, the difference in performance between control and minimally persuasive groups was significant (P=.05 for PEA and P=.02 for VFib/VTach). The pre-post comparison of performances of the groups showed that control (P=.017 for PEA, P=.01 for VFib/VTach) and persuasive (P=.02 for PEA, P=.048 for VFib/VTach) groups improved their performances significantly, whereas minimally persuasive group did not (P=.45 for PEA, P=.46 for VFib/VTach). Results also suggest that the benefit of persuasiveness is constrained by the potentially interruptive nature of these features.</AbstractText>Our results indicate that the VR-based ACLS training with proper feedback components can provide a learning experience similar to face-to-face training, and therefore could serve as a more easily accessed supplementary training tool to the traditional ACLS training. Our findings also suggest that the degree of persuasive features in VR environments have to be designed considering the interruptive nature of the feedback elements.</AbstractText>Copyright © 2014 Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,961 | Comparisons of prognostic factors between young and elderly patients with chronic heart failure. | The purpose in the present study was to compare prognostic risk factors between older and younger chronic heart failure (CHF) patients.</AbstractText>We examined 598 consecutive CHF patients (476 men and 122 women, mean age 61.4 ± 14.3 years) who underwent cardiopulmonary exercise testing, echocardiography and blood examination. We divided the 598 patients into two groups: the elderly group (age ≥75 years, n = 123) and the young group (age <75, n = 475). We compared blood testing data, exercise capacity, cardiac function and prognosis between the two groups. Patients were followed up (median 782 days) to register cardiac deaths or rehospitalization as a result of worsening heart failure.</AbstractText>Patients in the elderly group were associated with higher frequencies of atrial fibrillation and diuretic use than those in the young group. Patients in the elderly group had lower hemoglobin concentration, more impaired renal function, higher plasma B-type natriuretic peptide (BNP) levels, smaller left ventricular volume, longer deceleration time of early mitral wave and lower exercise capacity than those in the young group. There were 199 cardiac events during follow-up periods. As expected, Kaplan-Meier analysis showed that patients in the elderly group had higher cardiac event rates than those in the young group. In the young group, multivariable Cox hazard analysis showed that hemoglobin concentration, log BNP and peak VO(2) were independent predictors related to cardiac events. In contrast, in the elderly group, estimated glomerular filtration rate, atrial fibrillation and peak VO(2) were independent factors to predict adverse clinical outcomes.</AbstractText>Prognostic factors were different between the elderly and young patients in CHF.</AbstractText>© 2014 Japan Geriatrics Society.</CopyrightInformation> |
11,962 | Effects of potassium/lidocaine-induced cardiac standstill during cardiopulmonary resuscitation in a pig model of prolonged ventricular fibrillation. | Several studies in patients who underwent open heart surgery found that myocardial ischemic damage was reduced by potassium cardioplegia combined with lidocaine infusion. The authors evaluated the effects of potassium/lidocaine-induced cardiac standstill during conventional cardiopulmonary resuscitation (CPR) on myocardial injury and left ventricular dysfunction after resuscitation from prolonged ventricular fibrillation (VF) cardiac arrest in a pig model.</AbstractText>Ventricular fibrillation was induced in 16 pigs, and circulatory arrest was maintained for 14 minutes. Animals were then resuscitated by standard CPR. Animals were randomized at the start of CPR to receive 20 mL of saline (control group) or 0.9 mEq/kg potassium chloride and 1.2 mg/kg lidocaine diluted to 20 mL (K-lido group).</AbstractText>Seven animals in each group achieved return of spontaneous circulation (ROSC; p=1.000). Four of the K-lido group animals (50%) achieved ROSC without countershock. Resuscitated animals in the K-lido group required fewer countershocks (p=0.004), smaller doses of epinephrine (p=0.009), and shorter durations of CPR (p=0.004) than did the control group. The uncorrected troponin-I at 4 hours after ROSC was lower in the K-lido group compared with the control group (2.82 ng/mL, 95% confidence interval [CI]=1.07 to 3.38 ng/mL vs. 6.55 ng/mL, 95% CI=4.84 to 13.30 ng/mL; p=0.025), although the difference was not significant after Bonferroni correction. The magnitude of reduction in left ventricular ejection fraction (LVEF) between baseline and 1 hour after ROSC was significantly lower in the K-lido group (26.5%, SD±6.1% vs. 39.1%, SD±6.8%; p=0.004).</AbstractText>In a pig model of untreated VF cardiac arrest for 14 minutes, resuscitation with potassium/lidocaine-induced cardiac standstill during conventional CPR tended to reduce myocardial injury and decreased the severity of postresuscitation myocardial dysfunction significantly.</AbstractText>© 2014 by the Society for Academic Emergency Medicine.</CopyrightInformation> |
11,963 | Global and regional differences in cerebral blood flow after asphyxial versus ventricular fibrillation cardiac arrest in rats using ASL-MRI. | Both ventricular fibrillation cardiac arrest (VFCA) and asphyxial cardiac arrest (ACA) are frequent causes of CA. However, only isolated reports compared cerebral blood flow (CBF) reperfusion patterns after different types of CA, and even fewer reports used methods that allow serial and regional assessment of CBF. We hypothesized that the reperfusion patterns of CBF will differ between individual types of experimental CA. In a prospective block-randomized study, fentanyl-anesthetized adult rats were subjected to 8min VFCA or ACA. Rats were then resuscitated with epinephrine, bicarbonate, manual chest compressions and mechanical ventilation. After the return of spontaneous circulation, CBF was then serially assessed via arterial spin-labeling magnetic resonance imaging (ASL-MRI) in cortex, thalamus, hippocampus and amygdala/piriform complex over 1h resuscitation time (RT). Both ACA and VFCA produced significant temporal and regional differences in CBF. All regions in both models showed significant changes over time (p<0.01), with early hyperperfusion and delayed hypoperfusion. ACA resulted in early hyperperfusion in cortex and thalamus (both p<0.05 vs. amygdala/piriform complex). In contrast, VFCA induced early hyperperfusion only in cortex (p<0.05 vs. other regions). Hyperperfusion was prolonged after ACA, peaking at 7min RT (RT7; 199% vs. BL, Baseline, in cortex and 201% in thalamus, p<0.05), then returning close to BL at ∼RT15. In contrast, VFCA model induced mild hyperemia, peaking at RT7 (141% vs. BL in cortex). Both ACA and VFCA showed delayed hypoperfusion (ACA, ∼30% below BL in hippocampus and amygdala/piriform complex, p<0.05; VFCA, 34-41% below BL in hippocampus and amygdala/piriform complex, p<0.05). In conclusion, both ACA and VFCA in adult rats produced significant regional and temporal differences in CBF. In ACA, hyperperfusion was most pronounced in cortex and thalamus. In VFCA, the changes were more modest, with hyperperfusion seen only in cortex. Both insults resulted in delayed hypoperfusion in all regions. Both early hyperperfusion and delayed hypoperfusion may be important therapeutic targets. This study was approved by the University of Pittsburgh IACUC 1008816-1. |
11,964 | Performance of anesthesia residents during a simulated prone ventricular fibrillation arrest in an anesthetized pediatric patient. | Exposure to rare pediatric anesthesia emergencies varies depending on the residency program. Simulation can provide increased exposure to these rare events, improve performance of residents, and also aid in standardizing the curriculum.</AbstractText>The purpose of this study was to evaluate time to recognize and treat ventricular fibrillation in a pediatric prone patient and to expose learners to the difficulties of managing emergencies in prone patients.</AbstractText>Standardized simulation sessions were conducted monthly for 13 months with groups of 1-2 residents in each simulation. The scenario involved a prone patient undergoing posterior spinal fusion. Ventricular fibrillation occurred three minutes into the case. Sessions were viewed by simulation staff, and time to events was recorded. A scripted debriefing followed each case. Evaluations were completed by each participant.</AbstractText>The average time to start chest compressions was 77 s, and the average time in recognizing ventricular fibrillation was 76 s. No group performed chest compressions while prone. Only one group defibrillated in the prone position. Participants average time to request defibrillation was 108 s. While nine of 13 groups (69%) ordered an arterial blood gas, only five recognized hyperkalemia, and only four groups gave calcium.</AbstractText>Anesthesia residents need additional training in recognizing and treating operative ventricular fibrillation, especially in prone patients and rarely encountered etiologies such as hyperkalemia. Training in the treatment of uncommon pediatric emergencies should be a focal point in anesthesia residency programs.</AbstractText>© 2014 John Wiley & Sons Ltd.</CopyrightInformation> |
11,965 | F 16915 prevents heart failure-induced atrial fibrillation: a promising new drug as upstream therapy. | Atrial fibrillation (AF) is a common complication of heart failure. The aim of the present study was to investigate the effects of a new pure docosahexaenoic acid derivative called F 16915 in experimental models of heart failure-induced atria dysfunction. The atrial dysfunction-induced AF was investigated (1) in a dog model of tachypacing-induced congestive heart failure and (2) in a rat model of heart failure induced by occlusion of left descending coronary artery and 2 months reperfusion. F 16915 (5 g/day for 4 weeks) significantly reduced the mean duration of AF induced by burst pacing in the dog model (989 ± 111 s in the vehicle group to 79 ± 59 s with F 16915, P < 0.01). This dose of F 16915 also significantly reduced the incidence of sustained AF (5/5 dogs in the vehicle group versus 1/5 with F 16915, P < 0.05). In the rat model, the percentage of shortening fraction in the F 16915 group (100 mg/kg p.o. daily) was significantly restored after 2 months (32.6 ± 7.4 %, n = 9 vs 17.6 ± 3.4 %, n = 9 in the vehicle group, P < 0.01). F 16915 also reduced the de-phosphorylation of connexin43 from atria tissue. The present results show that treatment with F 16915 reduced the heart dilation, resynchronized the gap junction activity, and reduced the AF duration in models of heart failure. Thus, F 16915 constitutes a promising new drug as upstream therapy for the treatment of AF in patients with heart failure. |
11,966 | TED-Time and life saving External Defibrillator for home-use. | Sudden Cardiac Death--SCD --is a major unmet health problem that needs urgent and prompt solution. AICDs are very expensive, risky and indicated for a small group of patients, at the highest risk. AEDs--Automatic External Defibrillators--are designed for public places and although safe, cannot enter the home-market due to their cost and need for constant, high-cost maintenance. We developed TED, a low-cost AED that derives its energy off the mains, designed for home-use, to save SCD victims' lives. |
11,967 | Chronic right ventricular apical pacing: adverse effects and current therapeutic strategies to minimize them. | The permanent cardiac pacemaker is the only effective therapy for patients with symptomatic bradycardia and hundreds of millions are implanted worldwide every year. Despite its undisputed clinical benefits, the last two decades have drawn much attention to the negative effects associated with long-term pacing of the right ventricle (RV). Experimental and clinical studies have shown that RV pacing produces ventricular dyssynchrony, similar to that of left bundle branch block, with consequent detrimental effects on cardiac structure and function, with adverse clinical outcomes such as atrial fibrillation, heart failure and death. Although clinical evidence largely comes from subanalyses of pacemaker and implantable cardiac defibrillator studies, there is strong evidence that patients with reduced left ventricular function are at high risk of suffering from the detrimental effects of long-term RV pacing. Biventricular pacing in cardiac resynchronization therapy devices can prevent ventricular dyssynchrony and has emerged as an attractive option in this patient group with promising results and more clinical studies underway. Moreover, there is evidence that specific pacemaker algorithms that minimize RV pacing can reduce the negative effects of RV stimulation on cardiac function and may also prevent clinical deterioration. The extent of the long-term clinical effects of RV pacing in patients with normal ventricular function and how to prevent this are less clear and subject to future investigation. |
11,968 | Amiodarone induced epididymitis: a case report. | Amiodarone is an effective drug for life-threatening arrhythmias like recurrent ventricular fibrillation and atrial fibrillation. Amiodarone creates rarely genitourinary side effects are seen. These are epididymitis, testicular dysfunction and impotance. Amiodarone aggregates and triggers inflammation in the head of the epididym.</AbstractText>We present the case of a patient who developed epididymitis after 17 months of amiodarone therapy, using a low dose (100 mg per day). Although cessation of medication or dose lowering was not performed, remission of the patient only by analgesics is a distinct case reported in urological literature.</AbstractText>This case stresses the importance of considering an adverse effect of amiodarone treatment as a cause when making a differential diagnosis of epididymitis.</AbstractText> |
11,969 | Differences in clinical characteristics, management and short-term outcome between acute heart failure patients chronic obstructive pulmonary disease and those without this co-morbidity. | <AbstractText Label="AIM-METHODS" NlmCategory="UNASSIGNED">ALARM-HF was a retrospective, observational registry that included 4,953 patients admitted for acute heart failure (AHF) in six European countries, Turkey, Mexico and Australia. Data about respiratory disorders and related medications were available for 4,616 patients with AHF.</AbstractText>Chronic obstructive pulmonary disease (COPD) patients (n = 1,143, 24.8%) were older and more frequently men (p < 0.001) when compared to non-COPD patients. Despite the equivalent left ventricular ejection fraction (38.6 ± 13.7 vs. 38.2 ± 14.5%, p > 0.05), COPD patients more frequently presented with acutely decompensated heart failure (p < 0.001). Moreover, a worse cardiovascular profile was observed in the COPD group, including more atrial fibrillation/flutter, diabetes, hypertension, obesity, peripheral vascular disease (p < 0.001). Before admission, a higher percentage of COPD patients had experienced infections (25.0 vs. 14.0 %, p < 0.001), and were more likely to receive diuretics (p = 0.006), ACE inhibitors (p = 0.042), nitrates (p = 0.003), and digoxin (p = 0.034). With the exception of ACE inhibitors, those differences maintained at discharge, with concomitant increase in ARBs prescription (p = 0.01). Notably, β-blockers were less prescribed before admission (21.1 vs. 23.8%, p = 0.055) in COPD patients, and remained underutilized at discharge (p < 0.001). Correcting for baseline differences, all-cause in-hospital mortality did not differ between COPD and non-COPD groups (10.1 vs. 10.9%, p = 0.085).</AbstractText>A large proportion of AHF patients presented with concomitant COPD, had different clinical characteristics/co-morbidities, and less frequently received evidence-based pharmacological therapy compared to non-COPD patients. However, the in-hospital mortality was not higher in COPD group.</AbstractText> |
11,970 | Three vessel coronary cameral fistulae associated with new onset atrial fibrillation and angina pectoris. | Coronary cameral fistulas are abnormal communications between a coronary artery and a heart chamber or a great vessel which are reported in less than 0.1% of patients undergoing diagnostic coronary angiography. All three major coronary arteries are even less frequently involved in fistula formation as it is the case in our patient. A 68-year-old woman was admitted to cardiology clinic with complaints of exertional dyspnea and angina for two years and a new onset palpitation. Standard 12-lead electrocardiogram revealed atrial fibrillation (AF) with a ventricular rate of 114 beat/minute and accompanying T wave abnormalities and minimal ST-depression on lateral derivations. Transthoracic echocardiographic examination was normal except for diastolic dysfunction, minimally mitral regurgitation, and mild to moderate enlargement of the left atrium. Sinus rhythm was achieved by medical cardioversion with amiodarone infusion. Coronary angiography revealed diffuse and multiple coronary-left ventricle fistulas originating from the distal segments of both left and right coronary arterial systems without any stenosis in epicardial coronary arteries. The patient's symptoms resolved almost completely with medical therapy. High volume shunts via coronary artery to left ventricular microfistulas may lead to increased volume overload and subsequent increase in end-diastolic pressure of the left ventricle and may cause left atrial enlargement. |
11,971 | The predictive value of CHADS₂ risk score in post myocardial infarction arrhythmias - a Cardiac Arrhythmias and RIsk Stratification after Myocardial infArction (CARISMA) substudy. | Previous studies have shown substantially increased risk of cardiac arrhythmias and sudden cardiac death in post-myocardial infarction (MI) patients. However it remains difficult to identify the patients who are at highest risk of arrhythmias in the post-MI setting. The purpose of this study was to investigate if CHADS₂ score (congestive heart failure, hypertension, age ≥75 years, diabetes and previous stroke/TCI [doubled]) can be used as a risk tool for predicting cardiac arrhythmias after MI.</AbstractText>The study included 297 post-MI patients from the CARISMA study with left ventricular ejection fraction (LVEF) ≤40%. All patients were implanted with an implantable cardiac monitor (ICM) within 5 to 21 days post-MI and followed every three months for two years. Atrial fibrillation, bradyarrhythmias and ventricular tachycardias were diagnosed using the ICM, pacemaker or ICD. Patients were stratified according to CHADS₂ score at enrollment. Congestive heart failure was defined as LVEF ≤40% and NYHA class II, III or IV.</AbstractText>We found significantly increased risk of an arrhythmic event with increasing CHADS₂ score (CHADS₂ score=1-2: HR=2.1 [1.1-3.9], p=0.021, CHADS₂ score ≥ 3: HR=3.7 [1.9-7.1], p<0.001). This pattern was identical when dividing the arrhythmias into subgroups of atrial fibrillation, ventricular tachycardias and bradyarrhythmias. CHADS₂ score was similarly associated with the development of major cardiovascular events defined as reinfarction, stroke, and hospitalization for heart failure or cardiovascular death.</AbstractText>In the post-MI setting, CHADS₂ score efficiently identifies populations at high risk for cardiac arrhythmias.</AbstractText>Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
11,972 | Cardiac changes due to electronic control devices? A computer-based analysis of electrical effects at the human heart caused by an ECD pulse applied to the body's exterior. | Electronic control devices (ECDs) deliver high-voltage, low-current energy pulses temporarily paralyzing a person. For the ECD-human interaction, we have developed a computer model using the SEMCAD program within which to simulate the electrical effects throughout the body resulting from the imposition of an ECD pulse at a particular point on the body surface. Our human body models were based on cross-sectional MRIs and CT scans, with the dielectric properties of the various tissues assigned based on previously published values. We simulated the application of a single ECD pulse and calculated the resulting electric field strength and current and charge densities at different body locations. The results were compared with corresponding values obtained by other researchers in similar simulations. Furthermore, we simulated an application of a pulse of 20-millisecond duration equal to the European household current of 50 Hz and to the ventricular fibrillation threshold. The resulting current level indicated at the heart muscle was 1/5 the level considered the threshold for triggering ventricular fibrillation. |
11,973 | Diagnosis and management of patients with inherited arrhythmia syndromes in Europe: results of the European Heart Rhythm Association Survey. | Inherited arrhythmia disorders associated with structurally normal heart (i.e. long and short QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, early repolarization syndrome, idiopathic ventricular fibrillation) cause 10% of 1.1 million sudden deaths in Europe and the USA. The purpose of this European Heart Rhythm Association (EHRA) electrophysiology wire survey was to assess the European clinical practice adopted for the diagnosis and management of these disorders. The survey was based on an electronic questionnaire sent out to the EHRA Research Network centres. Responses were received from 50 centres in 23 countries. The results of the survey show that inherited arrhythmia syndromes have a relatively low burden and are diagnosed and managed in accordance with the current guidelines. However, more than 50% of centres do not participate in any existing registry underlining the need for establishing a pan-European registry of these disorders. |
11,974 | Clinical reasoning: A 68-year-old man with a first presentation of status epilepticus. | A 64-year-old man with transfusion-dependent myelodysplastic syndrome (MDS), hypertension, chronic obstructive pulmonary disease, hypothyroidism, blindness from treated syphilitic chorioretinitis, and no prior seizure history presented in generalized status epilepticus. His daily home medication regimen included prednisone 20 mg (chronic therapy for MDS), diltiazem 120 mg, digoxin 250 μg, tiotropium 80 μg, and levothyroxine 112 μg. On admission he was febrile to 39.9 °C and in atrial fibrillation with rapid ventricular rate. Initial hematologic profile showed 11,910 leukocytes/mm(3) (12% immature forms, 46% neutrophils, 32% lymphocytes), hematocrit of 30.8%, and platelet count of 215,000/mm(3), with an otherwise normal serum chemistry. |
11,975 | Electromagnetic interference of implantable cardiac devices from a shoulder massage machine. | Shoulder massage machines have two pads that are driven by solenoid coils to perform a per cussive massage on the shoulders. There have been concerns that such machines might create electromagnetic interference (EMI) in implantable cardiac devices because of the time-varying magnetic fields produced by the alternating current in the solenoid coils. The objective of this study was to investigate the potential EMI from one such shoulder massage machine on implantable cardiac devices. We measured the distribution profile of the magnetic field intensity around the massage machine. Furthermore, we performed an inhibition test and an asynchronous test on an implantable cardiac pacemaker using the standardized Irnich human body model. We examined the events on an implantable cardioverter-defibrillator (ICD) using a pacemaker programmer while the massage machine was in operation. The magnetic field distribution profile exhibited a peak intensity of 212 (A/m) in one of the solenoid coils. The maximal interference distance between the massage machine and the implantable cardiac pacemaker was 28 cm. Ventricular fibrillation was induced when the massage machine was brought near the electrode of the ICD and touched the Irnich human body model. It is necessary to provide a "don't use" warning on the box or the exterior of the massage machines or in the user manuals and to caution patients with implanted pacemakers about the dangers and appropriate usage of massage machines. |
11,976 | Reduction of unnecessary right ventricular pacing by managed ventricular pacing and search AV+ algorithms in pacemaker patients: 12-month follow-up results of a randomized study. | The present study was to assess the reduction of right ventricular pacing (RVP) by pacemaker algorithms of Managed Ventricular Pacing (MVP) and Search AV+ (SAV+) interval over a period of 12 months.</AbstractText>A total of 385 patients indicated for a dual-chamber pacemaker (DC-PM) were enrolled in the prospective, randomized COMPARE study at 29 centres in China between June 2009 and April 2011. Patients implanted with DC-PMs were randomized in a 1 : 1 ratio to the MVP group or the SAV+ group. The percentage of VP (%VP) was obtained from the device diagnostic data at 1-, 6-, and 12-month follow-ups and was expressed as the median %VP over all beats in patients with sinus node dysfunction (SND) and atrioventricular block (AVB) excluding persistent third-degree AVB. Of 385 enrolled patients, 253 had SND and 72 had AVB. The %VP in the MVP group was significantly lower than that in the SAV+ group at 1-, 6-, and 12-month follow-ups, respectively. At 12-month follow-up, the median %VP in SND patients was 0.20% in the MVP group and 1.4% in the SAV+ group (P < 0.0001) and the median %VP in AVB patients was 11.8% in the MVP group and 98.1% in the SAV+ group (P < 0.001). There was no statistical difference in %VP from 1- to 12-month follow-up. A trend in the correlation between %VP and AT/AF burden was observed.</AbstractText>Over 12-month follow-up, the %VP was lower for MVP than SAV+ in patients with either SND or AVB. The sustainable %VP reduction has potential implications in reducing the development of heart failure and/or atrial arrhythmia morbidity.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,977 | Cardiac contractility modulation: first experience in heart failure patients with reduced ejection fraction and permanent atrial fibrillation. | Cardiac contractility modulation (CCM) is an electrical therapy for heart failure (HF) with reduced ejection fraction. Sinus rhythm is deemed necessary for effective treatment because the current CCM signal delivery algorithm requires sequential sensing of a p wave, followed by depolarizations at each ventricular lead. In case of atrial fibrillation (AF) CCM is inhibited. This study demonstrates the feasibility of CCM therapy in patients with permanent AF by circumventing the requirement for sensing of a natural p wave.</AbstractText>Five CCM patients with AF received a pacemaker or implantable cardioverter/defibrillator (ICD) upgrade to cardiac resynchronization therapy (CRT) with low atrial sensitivity, which resulted in compulsory atrial stimulation followed by biventricular pacing. The CCM system recognized the atrial stimuli as p waves, which led to CCM signal delivery. Three patients developed permanent AF after a mean follow-up of 40 months of CCM therapy. Two patients had permanent AF at the time of CCM device implantation. All pacemaker or ICD devices were successfully upgraded to CRT. Cardiac resynchronization therapy stimulation rates of ≥96% and CCM stimulation rates between 60% and 95% were achieved. Clinical condition of the patients improved (mean NYHA class -0.7, left ventricular ejection fraction +2%, Minnesota living with HF questionnaire -15.6 points).</AbstractText>CCM signal delivery is feasible in HF patients with permanent AF by sequential atrial-ventricular pacing, so that the atrial pacing spike is interpreted as a p wave by the CCM signal delivery algorithm. This experimental approach can be considered in individual cases. A new CCM algorithm, which does not require an atrial electrode, is desirable.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,978 | High prevalence of cardiac involvement in patients with myotonic dystrophy type 1: a cross-sectional study. | Patients with myotonic dystrophy type 1 (DM1) have a three-fold higher risk of sudden cardiac death (SCD) than age-matched healthy controls. Despite numerous attempts to define the cardiac phenotype and natural history, existing literature suffers from low power, selection-bias and lack of controls. Thus, the optimal strategy for assessing cardiac involvement in DM1 is unclear.</AbstractText>In this large single-centre study, we evaluated 129 unselected DM1 patients (49.6% men), mean (SD) age 44 (14.7) years with family history, physical examination, electrocardiogram (ECG), echocardiography, Holter-monitoring and muscle strength testing.</AbstractText>Cardiac involvement was found in 71 patients (55%) and included: 1) Conduction abnormalities: atrio-ventricular block grade I (AVB grade I) (23.6%), AVB grade II (5.6%), right/left bundle branch block (5.5/3.2%) and prolonged QTc (7.2%); 2) arrhythmias: atrial fibrillation/flutter (4.1%), other supraventricular tachyarrhythmia (7.3%) and non-sustained ventricular tachycardia (4.1%); and 3) structural abnormalities: left ventricular systolic dysfunction (20.6%) and reduced global longitudinal strain (21.7%). A normal ECG was not significantly associated with normal findings on Holter-monitoring or echocardiography. Patients with abnormal cardiac findings had weaker muscle strength than those with normal cardiac findings: ankle dorsal flexion (median (range) 4.5 (0-5) vs. 5.0 (2.5-5), p=0.004) and handgrip (median 4.0 (0-5) vs. 4.50 (2-5), p=0.02).</AbstractText>The cardiac phenotype of DM1 includes a high prevalence of conduction disorders, arrhythmias and risk factors of SCD. Systematic cardiac screening with ECG, Holter-monitoring and echocardiography is needed in order to make a proper characterization of cardiac involvement in DM1.</AbstractText>Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
11,979 | Electrocardiographic parameters and fatal arrhythmic events in patients with Brugada syndrome: combination of depolarization and repolarization abnormalities. | This study aimed to determine the usefulness of the combination of several electrocardiographic markers on risk assessment of ventricular fibrillation (VF) in patients with Brugada syndrome (BrS).</AbstractText>Detection of high-/low-risk BrS patients using a noninvasive method is an important issue in the clinical setting. Several electrocardiographic markers related to depolarization and repolarization abnormalities have been reported, but the relationship and usefulness of these parameters in VF events are unclear.</AbstractText>Baseline characteristics of 246 consecutive patients (236 men; mean age, 47.6 ± 13.6 years) with a Brugada-type electrocardiogram, including 13 patients with a history of VF and 40 patients with a history of syncope episodes, were retrospectively analyzed. During the mean follow-up period of 45.1 months, VF in 23 patients and sudden cardiac death (SCD) in 1 patient were observed. Clinical/genetic and electrocardiographic parameters were compared with VF/SCD events.</AbstractText>On univariate analysis, a history of VF and syncope episodes, paroxysmal atrial fibrillation, spontaneous type 1 pattern in the precordial leads, and electrocardiographic markers of depolarization abnormalities (QRS duration ≥120 ms, and fragmented QRS [f-QRS]) and those of repolarization abnormalities (inferolateral early repolarization [ER] pattern and QT prolongation) were associated with later cardiac events. On multivariable analysis, a history of VF and syncope episodes, inferolateral ER pattern, and f-QRS were independent predictors of documented VF and SCD (odds ratios: 19.61, 28.57, 2.87, and 5.21, respectively; p < 0.05). Kaplan-Meier curves showed that the presence/absence of inferolateral ER and f-QRS predicted a worse/better prognosis (log-rank test, p < 0.01).</AbstractText>The combination of depolarization and repolarization abnormalities in BrS is associated with later VF events. The combination of these abnormalities is useful for detecting high- and low-risk BrS patients.</AbstractText>Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,980 | Outcomes by rescue shock number during the metabolic phase of porcine ventricular fibrillation resuscitation. | Optimal resuscitation duration before the first rescue shock (RS) to maximize the probability of success after prolonged ventricular fibrillation (VF) cardiac arrest remains unknown. The purpose of this study was to determine the occurrence of return of spontaneous circulation (ROSC) and survival by RS attempt after 12 minutes of untreated VF.</AbstractText>This was a secondary analysis of prospectively collected data from an institutional animal care and use committee-approved protocol. Fifty-three swine (30-35 kg) were instrumented under anesthesia. Ventricular fibrillation was electrically induced. After 12 minutes of untreated VF, cardiopulmonary resuscitation (CPR) was initiated (and continued as necessary (prn)) and a standard dose of epinephrine (0.01 mg/kg) was given (and repeated every 3 (q3) minutes prn). The first RS was delivered after 3 minutes of CPR (and q3 minutes thereafter prn). Each failed RS was followed (in series) by vasopressin (0.57 mg/kg), amiodarone (4.3 mg/kg), and sodium bicarbonate (1 mEq/kg) prn. Resuscitation continued until ROSC or 20-minute elapsed time. The primary outcomes were ROSC and 20-minute survival. Data were analyzed using descriptive statistics.</AbstractText>After 3 minutes of resuscitation, 1 animal (1.9% [95% confidence interval {CI, 0.3-10.0]) achieved ROSC on RS1 and survived. After 6 minutes of resuscitation, 17 animals (32.1% [95% CI, 21.1-45.5]) achieved ROSC on RS2 and 15 (28.3% [95% CI, 18.0-41.6]) survived. Twelve additional animals had ROSC and survival with continued resuscitation. In 23 animals, ROSC was never achieved and efforts were terminated per protocol.</AbstractText>Our data suggest that during the metabolic phase of VF, 3 minutes of CPR and 1 standard dose of epinephrine may be insufficient to achieve ROSC on the first RS attempt. A longer duration of CPR and/or additional vasopressors may increase the likelihood of successful defibrillation.</AbstractText>Copyright © 2014 Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,981 | Relation of interatrial block to new-onset atrial fibrillation in patients with Chagas cardiomyopathy and implantable cardioverter-defibrillators. | Chagas cardiomyopathy is an endemic disease in Latin America. A significant proportion of patients develop atrial fibrillation (AF), which may result in stroke and increased morbidity or mortality. Interatrial block (IAB) has been associated with the development of AF in different clinical scenarios. The aim of our study was to determine whether IAB can predict new-onset AF in patients with Chagas cardiomyopathy and implantable cardioverter-defibrillators (ICDs). We conducted a retrospective study of patients with Chagas cardiomyopathy and ICDs from 14 centers in Latin America. Demographics, clinical, and device follow-up were collected. Surface electrocardiograms were scanned at 300 dpi and maximized ×8. Semiautomatic calipers were used to determine P-wave onset and offset. Partial IAB was defined as a P wave of >120 ms and advanced IAB as a P wave of >120 ms with biphasic morphology (±) in inferior leads. AF events and ICD therapies were reviewed during follow-up by 2 independent investigators. A total of 80 patients were analyzed. Mean age was 54.6 ± 10.4 years, and 52 (65%) were male. Mean left ventricular ejection fraction was 40 ± 12%. IAB was detected in 15 patients (18.8%), with 8 (10.0%) partial and 7 (8.8%) advanced. During a follow-up of 33 ± 20 months, 11 patients (13.8%) presented with new AF. IAB (partial + advanced) was strongly associated with new AF (p <0.0001) and inappropriate therapy by the ICD (p = 0.014). In conclusion, IAB (partial + advanced) predicted new-onset AF in patients with Chagas cardiomyopathy and ICDs. |
11,982 | Effectiveness of atrial fibrillation monitor characteristics to predict severity of symptoms of atrial fibrillation. | The goal of treatment for atrial fibrillation (AF) is often to control symptoms. It remains unclear whether targets for treatment such as AF rate or AF burden are correlated with AF symptom severity. Two hundred eighty-six patients completed a questionnaire of their general health and well-being, including a detailed AF symptom assessment immediately followed by a 7-day continuous monitor. AF characteristics assessed from the monitor included AF burden, AF rate, sinus rhythm rate, frequency and severity of pauses, and premature atrial contraction or premature ventricular contraction burden. Characteristics were analyzed separately for patients with paroxysmal or persistent AF. Symptom severity was assessed using the University of Toronto Atrial Fibrillation Severity Scale. Monitor characteristics were compared with AF symptom severity. The mean age of the cohort was 61.8 years and the majority of subjects were male (65.4%). Co-morbidities included hypertension (64.5%), sleep apnea (38.4%), congestive heart failure (19.6%), and diabetes (16.4%). In those with persistent or paroxysmal AF, there were no significant predictors of AF symptom severity. Specifically, heart rate in AF or sinus rhythm, AF burden, or premature atrial contraction or premature ventricular contraction burden was not predictive of AF symptom severity. After adjusting for potential cofounders (including age, gender, and co-morbidities), these findings persisted. In conclusion, there is no value in using AF monitor characteristics to predict symptoms in patients with AF. |
11,983 | Impaired cerebral mitochondrial oxidative phosphorylation function in a rat model of ventricular fibrillation and cardiopulmonary resuscitation. | Postcardiac arrest brain injury significantly contributes to mortality and morbidity in patients suffering from cardiac arrest (CA). Evidence that shows that mitochondrial dysfunction appears to be a key factor in tissue damage after ischemia/reperfusion is accumulating. However, limited data are available regarding the cerebral mitochondrial dysfunction during CA and cardiopulmonary resuscitation (CPR) and its relationship to the alterations of high-energy phosphate. Here, we sought to identify alterations of mitochondrial morphology and oxidative phosphorylation function as well as high-energy phosphates during CA and CPR in a rat model of ventricular fibrillation (VF). We found that impairment of mitochondrial respiration and partial depletion of adenosine triphosphate (ATP) and phosphocreatine (PCr) developed in the cerebral cortex and hippocampus following a prolonged cardiac arrest. Optimal CPR might ameliorate the deranged phosphorus metabolism and preserve mitochondrial function. No obvious ultrastructural abnormalities of mitochondria have been found during CA. We conclude that CA causes cerebral mitochondrial dysfunction along with decay of high-energy phosphates, which would be mitigated with CPR. This study may broaden our understanding of the pathogenic processes underlying global cerebral ischemic injury and provide a potential therapeutic strategy that aimed at preserving cerebral mitochondrial function during CA. |
11,984 | Electrophysiological profile of vernakalant in an experimental whole-heart model: the absence of proarrhythmia despite significant effect on myocardial repolarization. | The most recent European Society of Cardiology (ESC) update on atrial fibrillation has introduced vernakalant (VER) for pharmacological cardioversion of atrial fibrillation. The aim of the present study was to investigate the safety profile of VER in a sensitive model of proarrhythmia.</AbstractText>In 36 Langendorff-perfused rabbit hearts, VER (10, 30 µM, n = 12); ranolazine (RAN, 10, 30 µM, n = 12), or sotalol (SOT, 50; 100 µM, n = 12) were infused after obtaining baseline data. Monophasic action potentials and a 12-lead electrocardiogram showed a significant QT prolongation after application of VER as compared with baseline (10 µM: +25 ms, 30 µM: +50 ms, P < 0.05) accompanied by an increase of action potential duration (APD). The increase in APD90 was accompanied by a more marked increase in effective refractory period (ERP) leading to a significant increase in post-repolarization refractoriness (PRR, 10 µM: +30 ms, 30 µM: +36 ms, P < 0.05). Vernakalant did not affect the dispersion of repolarization. Lowered potassium concentration in bradycardic hearts did not provoke early afterdepolarizations (EADs) or polymorphic ventricular tachycardia (pVT). Comparable results were obtained with RAN. Hundred micromolars of SOT led to an increase in QT interval (+49 ms) and APD90 combined with an increased ERP and PRR (+23 ms). In contrast to VER, 100 µM SOT led to a significant increase in dispersion of repolarization and to the occurrence of EAD in 10 of 12 and pVT in 8 of 12 hearts.</AbstractText>In the present study, application of VER and SOT led to a comparable prolongation of myocardial repolarization. Both drugs increased the PRR. However, VER neither affect the dispersion of repolarization nor induce EAD and therefore did not cause proarrhythmia.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,985 | Factors associated with atrial fibrillation in rheumatic mitral stenosis. | Atrial fibrillation is a complication of mitral valve stenosis that causes several adverse neurologic outcomes. Our objective was to establish a mathematical model to predict the risk of atrial fibrillation in patients with mitral stenosis.</AbstractText>Of 819 patients with mitral stenosis who were screened, 603 were enrolled in the study and grouped according to whether they were in sinus rhythm or atrial fibrillation. Demographic, echocardiographic, and hemodynamic data were recorded. Logistic regression models were constructed to identify the relative risks for each contributing factor and calculate the probability of developing atrial fibrillation. Receiver operating characteristic curves were plotted.</AbstractText>Two hundred (33%) patients had atrial fibrillation; this group was older, in a higher functional class, more likely to have suffered previous thromboembolic events, and had significantly larger left atrial diameters, lower ejection fractions, and lower left atrial appendage emptying flow velocity. The factors independently associated with atrial fibrillation were left atrial strain (odds ratio = 7.53 [4.47-12.69], p < 0.001), right atrial pressure (odds ratio = 1.09 [1.02-1.17], p = 0.01), age (odds ratio = 1.14 [1.05-1.25], p = 0.002), and ejection fraction (odds ratio = 0.92 [0.87-0.97], p = 0.003). The area under the curve for the combined receiver operating characteristic for this model was 0.90 ± 0.12.</AbstractText>Age, right atrial pressure, ejection fraction, and left atrial strain can be used to construct a mathematical model to predict the development of atrial fibrillation in rheumatic mitral stenosis.</AbstractText>© The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.</CopyrightInformation> |
11,986 | First-degree atrioventricular block is associated with advanced atrioventricular block, atrial fibrillation and left ventricular dysfunction in patients with hypertension. | Clinical significance of first-degree atrioventricular block (AVB) have not been known in patients with hypertension. This study was performed to elucidate long-term prognosis of first-degree AVB in patients with hypertension.</AbstractText>We included 3816 patients (mean age, 61.0 ± 10.6 years; men, 47.2%) with hypertension. We reviewed their ECGs and measured the PR interval. The patients were divided into two groups: normal PR interval (120 ms ≤ PR ≤200 ms) and first-degree AVB (PR >200 ms). We compared the incidence, cumulative incidence and hazard ratios of advanced AVB, sick sinus syndrome, atrial fibrillation and left ventricular dysfunction between the two groups during the follow-up period.</AbstractText>The prevalence of first-degree AVB in patients with hypertension was 14.3%. The patients were followed up for 9.4 ± 2.4 years. Incidence and cumulative incidence of advanced AVB, atrial fibrillation and left ventricular dysfunction in patients with first-degree AVB were significantly higher than in patients with normal PR interval. By multivariate Cox's regression, patients with first-degree AVB had an increased risk of advanced AVB [hazard ratio 2.77; 95% confidence interval (95% CI) 1.38-5.59; P = 0.004], atrial fibrillation (hazard ratio 2.33; 95% CI 1.84-2.94; P < 0.001) and left ventricular dysfunction (hazard ratio 1.49; 95% CI 1.11-2.00; P = 0.009). However, sick sinus syndrome was not associated with first-degree AVB.</AbstractText>First-degree AVB is an independent risk factor for future development of advanced AVB, atrial fibrillation and left ventricular dysfunction in patients with hypertension.</AbstractText> |
11,987 | Status 2 patients had poor prognosis without mechanical circulatory support. | Indication for mechanical circulatory support (MCS) has been a matter of debate in less sick status 2 patients.</AbstractText>Data were obtained from 183 consecutive patients assigned to stage D heart failure (HF) who were evaluated by the institutional review board of the University of Tokyo Hospital and then listed for heart transplantation as status 1 or 2 of the Japan Organ Transplant Network. Patients with status 2 (n=38) had a prognosis as poor as those dependent on inotropes (n=54) or MCS (n=91; P=0.615, log-rank test), and only 4 of them had eventual ventricular assist device (VAD) implantation (10.5%). Patients who eventually received VAD (n=92) had better 4-year survival than those without MCS among status 1 and 2 (P=0.030, log-rank test). On Cox regression analysis plasma B-type natriuretic peptide (BNP) >740pg/ml was the only significant predictor for 4-year survival among the status 2 group (P=0.014; hazard ratio, 8.267). Ten patients with status 2 died: 6 due to acute hemodynamic compromise and 4 due to ventricular fibrillation.</AbstractText>Prognosis in status 2 patients was as poor as that of those dependent on inotrope infusion or VAD, mostly because of out-of-hospital sudden death without MCS. Status 2 patients with considerably high plasma BNP may be good candidates for continuous flow VAD therapy.</AbstractText> |
11,988 | Multiform premature ventricular contractions and polymorphic ventricular tachycardia caused by Purkinje activity with slow conduction in idiopathic ventricular fibrillation. | In several cases with idiopathic ventricular fibrillation (VF), VF was initiated by premature ventricular contractions (PVCs) from the Purkinje system. However, the precise characteristics of the Purkinje activity in patients with idiopathic VF remain unclear. We performed an electrophysiological study in a patient with idiopathic VF and examined the correlation between the Purkinje potential and the incidence of PVCs/polymorphic ventricular tachycardia (PMVT). In this case of idiopathic VF, the Purkinje activity caused multiform PVCs and PMVT. The The Purkinje activity and slow conduction of Purkinje fibers are associated with the occurrence of multiform PVCs and PMVT. |
11,989 | Impact of pulmonary vein isolation on left bundle branch block following tachycardia-induced cardiomyopathy in a patient with persistent atrial fibrillation. | A 61-year-old man was referred to our hospital with exertional dyspnea. Electrocardiography showed atrial fibrillation (AF) with a heart rate of 116 bpm and left bundle branch block (LBBB). Chest radiography demonstrated pulmonary congestion and cardiomegaly with a cardiothoracic ratio of 57%. Transthoracic echocardiography revealed a severely reduced left ventricular systolic function (ejection fraction: 32%), suggesting tachycardia-induced cardiomyopathy (TIC) due to AF. Following treatment for congestive heart failure and complete isolation of each pulmonary vein, the LBBB disappeared, with a complete recovery of the cardiac systolic function. This report describes a case of transient reversible LBBB associated with systolic dysfunction treated with catheter ablation. |
11,990 | Transient and rapid QRS-widening associated with a J-wave pattern predicts impending ventricular fibrillation in experimental myocardial infarction. | Certain types of the early repolarization phenomenon, previously considered to be benign, have been reported to be associated with ventricular fibrillation (VF), both in population-based studies and in the myocardial infarction (MI) settings.</AbstractText>To analyze whether QRS widening and appearance of a J-wave pattern in experimental MI settings is predictive of VF.</AbstractText>MI was induced in 32 pigs by 40-minute inflation of an angioplasty balloon in the left descending artery, and electrocardiogram was continuously recorded. Multilead QRS boundaries were computed, and QRS duration was calculated on a beat-to-beat basis during the occlusion period for each pig. An association between QRS widening and subsequent VF was studied using receiver operating characteristic curve analysis. Electrocardiograms at maximum QRS duration were reviewed for the presence of a J-wave pattern.</AbstractText>Sixteen animals had VF episodes during the occlusion period. Two peaks of QRS widening were found in all animals: the first peak immediately on left descending artery occlusion and the second peak 19.1 ± 4.0 minutes later. The magnitude of changes in the QRS width over time had significant interindividual differences. A QRS widening of ≥28 ms during a 3-minute time window was observed in 14 animals and predicted impending VF (selectivity 80%, specificity 73%, positive predictive value 57%, and negative predictive value 89%; P = .008). In 10 of 14 (71%) pigs, a J-wave pattern appeared at maximal QRS duration. The appearance of a J-wave pattern predicted VF with selectivity 80%, specificity 68%, positive predictive value 53%, and negative predictive value 88% (P = .02).</AbstractText>Transient QRS widening, commonly associated with a J-wave pattern, appears to predict impending VF in acute ischemia settings and motivates further clinical studies for monitoring immediate risk of VF in MI.</AbstractText>Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,991 | Silent atrial fibrillation after ischemic stroke or transient ischemic attack: interest of continuous ECG monitoring. | Since atrial fibrillation (AF) may be undiagnosed when asymptomatic and paroxysmal, we aimed to investigate the incidence and determinants of silent AF in patients with acute ischemic stroke or transient ischemic attack (TIA).</AbstractText>Consecutive patients admitted to the Stroke Unit of the University Hospital of Dijon, France, for acute ischemic stroke or TIA were prospectively enrolled from March to December 2012. Silent AF was assessed by continuous electrocardiography (ECG) monitoring for 24 h after admission. An echocardiography was performed at day 2 ± 1 to measure left ventricular ejection fraction (LVEF) and left auricular (LA) dimensions.</AbstractText>Among the 187 patients included, 19 (10%) developed silent AF. Patients with silent AF were markedly older (76 vs. 66 years, p < 0.002), with lower creatinine levels (90 vs. 80 µmol/l, p = 0.030) and were less often smokers (5 vs. 24%, p = 0.058) than patients without silent AF. They also showed a trend towards more frequent hypertension and a recent history of infection. Patients with silent AF had a larger indexed LA volume (37.4 vs. 30.8 ml/m(3), p = 0.057) and LA diameter (23.2 vs. 20.8 mm/m(2), p = 0.059). LVEF in the two groups was similar. In multivariate analysis, only age remained an independent estimate of silent AF.</AbstractText>Silent AF detected by continuous ECG monitoring is common and closely associated with older age. Further studies are needed to investigate the interest of systematically screening for silent AF for secondary prevention after ischemic stroke/TIA.</AbstractText>© 2014 S. Karger AG, Basel.</CopyrightInformation> |
11,992 | The effect of acute simvastatin administration on the severity of arrhythmias resulting from ischaemia and reperfusion in the canine: Is there a role for nitric oxide? | The present study has examined the effects and the possible mechanisms of a single dose of simvastatin on the severity of arrhythmias resulting from a 25min occlusion and reperfusion of the left anterior descending coronary artery in anaesthetized (chloralose and urethane) dogs. The control animals (n=16) were given the solvent of simvastatin by slow (over 5min) intracoronary (ic.) injection just prior to the occlusion. Twenty-six dogs were treated with simvastatin (0.1mg/kg) by the same route, both in the absence (n=15) and in the presence (n=11) of l-NAME. This latter was administered (5mg/kg, ic.) either alone (n=12) or 10min before the simvastatin treatment. The severity of ischaemia (epicardial ST-segment, inhomogeneity) and ventricular arrhythmias (ventricular premature beats [VPBs], ventricular tachycardia [VT] and fibrillation [VF]), plasma nitrite/nitrate levels, myocardial superoxide production and eNOS activity were assessed. Compared with controls simvastatin significantly reduced the number of VPBs (289±34vs. 94±25) and the episodes of VT (5.6±1.3vs. 0.3±0.2), the incidence of VT (88% vs. 20%) and VF (56% vs. 0%) during occlusion and increased survival (0% vs. 33%) on reperfusion. There were also less marked ischaemic changes in the simvastatin-treated dogs than in the controls. Simvastatin preserved eNOS activity and nitric oxide (NO) bioavailability during occlusion and attenuated superoxide production following reperfusion. All these effects of simvastatin (except for the protection against VF) were reversed by l-NAME. We conclude that simvastatin given just prior to ischaemia/reperfusion reduces the severity of arrhythmias. This effect involves both NO-dependent and NO-independent mechanisms. |
11,993 | Ventricular rate monitoring as a tool to predict and prevent atrial fibrillation-related inappropriate shocks in heart failure patients treated with cardiac resynchronisation therapy defibrillators. | Inappropriate implantable cardioverter defibrillators (ICD) therapies have been associated with multiple adverse effects, including worse quality of life and prognosis. We evaluated the possibility of predicting atrial fibrillation (AF)-related inappropriate ICD shocks through continuous monitoring of device diagnostics.</AbstractText>1404 ICD patients were prospectively followed in an observational research by 74 Italian cardiology centres. Device diagnostics stored daily information on AF duration and ventricular rate (VR) during AF. Uncontrolled VR was defined as mean VR>80 beats per minute (bpm) and maximum VR>110 bpm. Expert electrophysiologists reviewed the ventricular tachycardia/ventricular fibrillation (VT/VF) episodes electrograms, stored in the device memory, and classified appropriate detections, inappropriate detection mechanisms and ICD therapy outcomes.</AbstractText>Over a median follow-up of 31 months, 511 (36%) patients suffered spontaneous VT/VF, which were treated by ICD shocks in a subgroup of 189 (13%) patients. Inappropriate detections occurred in 232 (16%) patients, and inappropriate ICD shocks in 101 (7%) patients. AF was the cause of inappropriate shocks in 60 patients. AF caused 144 inappropriate shocks: 53% of all inappropriate shocks. The likelihood of experiencing AF-related inappropriate shocks was 2.4% at 1 year and 6% at 5 years. Uncontrolled VR during AF proved to be an independent predictor of AF-related inappropriate shocks (OR=3.02, p=0.006); an alarm set at a VR>90 bpm or 100 bpm was associated with prediction of AF-related inappropriate shocks with a sensitivity of 73% or 62%, respectively.</AbstractText>AF is the most common cause of inappropriate shocks in ICD patients. Continuous remote monitoring of VR during AF would promptly and efficiently predict AF-related inappropriate shocks.</AbstractText>http://clinicaltrials.gov/ct2/show/NCT01007474.</AbstractText> |
11,994 | Renal denervation: effects on atrial electrophysiology and arrhythmias. | Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with significant morbidity and mortality. Currently, atrial endocardial catheter ablation, mainly targeting focal discharges in the pulmonary veins, is the most widely used interventional treatment of drug-refractory AF. Despite technical improvements, results are not yet optimal. There is ongoing search for alternative and/or complementary interventional targets. Conditions associated with increased sympathetic activation such as hypertension, heart failure and sleep apnea lead to structural, neural and electrophysiological changes in the atrium thereby contributing to the progression from paroxysmal to persistent AF and increasing recurrence rate of AF after PVI. Until now, interventional modulation of autonomic nervous system was limited by highly invasive techniques. Catheter-based renal denervation (RDN) was introduced as a minimally invasive approach to reduce renal and whole body sympathetic activation with accompanying blood pressure control and left-ventricular morphological and functional changes in resistant hypertension. This review focuses on the potential atrial antiarrhythmic and antiremodeling effects of RDN in AF patients with hypertension, heart failure, and sleep apnea and discusses the possible role of RDN in the treatment of AF. |
11,995 | Expanding role of SK channels in cardiac electrophysiology. | The small conductance calcium-activated potassium (SK) channels are an important group of potassium-selective ion channels. SK channels display more pronounced expression in the atrium relative to the ventricle. Current evidence relating to the functional role of SK channels in the atria is conflicting and whether these channels contribute to atrial repolarization under physiological circumstances is a matter of debate. Multiple studies have, however, reported that SK channels are important mediators of proarrhythmogenic electrical remodeling in the atria. In keeping with their expression profile, SK channels do not appear to play a prominent role in ventricular repolarization. SK channels represent potentially attractive therapeutic targets for atrial fibrillation. A number of pharmacological modulators of SK channels have been tested in animal models of atrial fibrillation. However, these studies have also demonstrated inconsistent results and have raised important questions regarding the proarrhythmogenic potential of SK channel modulation. These findings have important implications for drug development. This review summarizes the role of SK channels in cardiac electrophysiology and discusses the potential role of these channels as therapeutic targets. |
11,996 | Comprehensive clinical evaluation of a large Spanish family with Anderson-Fabry disease, novel GLA mutation and severe cardiac phenotype. | Fabry disease is an X-linked multisystemic lysosomal-storage condition. We describe a large family with a novel GLA mutation: p.M187R/g7219 T>G.</AbstractText>Anamnesis/physical-exam, blood/urine analysis, α-Gal-A activity and/or genetic study of at-risk individuals and multidisciplinary evaluation in confirmed cases.</AbstractText>4 males and 13 heterozygous-females displayed the mutation. Cardiac/renal/neurological disease was diagnosed at a mean age of 41/29/39 years in males and 51/56/46 years in females. Onset mean age was 20 years versus 42 years. 9/15 had cardiomyopathy. Delta wave suggestive of accessory pathway was identified in 1 male and 2 females. 1 female had cardiac arrest (ventricular fibrillation, 61 years). 2 females and 1 male died suddenly (63, 64 and 57 years). Cardiac-subscore of Mainz Severity-Score-Index was severe for males and females over 40 years. 4/15(26%) developed early renal disease. 2 males needed dialysis. 1 male died at 69 years in spite of kidney-heart transplant.</AbstractText>We describe the largest genetically confirmed Spanish family using multidisciplinary evaluation and MSSI calculation. The novel mutation p.M187R/g7219 T>G is associated with a particularly malignant cardiac phenotype in males and females over 40 years. Severity was higher than that of the largest Spanish FOS-cohort. Short-PR with delta is being reported for the first time.</AbstractText>Copyright © 2013 Elsevier España, S.L. All rights reserved.</CopyrightInformation> |
11,997 | Incremental value of three-dimensional echocardiography in the evaluation of left ventricular size in mitral regurgitation: a follow-up study after mitral valve surgery. | Increased left ventricular (LV) dimensions are an indication for surgery in patients with asymptomatic mitral regurgitation, but M-mode or two-dimensional measurements have known limitations. The aim of this study was to determine the value of three-dimensional echocardiography in predicting postoperative outcomes after mitral surgery.</AbstractText>Sixty-seven patients with severe asymptomatic or minimally symptomatic mitral regurgitation (69% men; mean age, 62 ± 13 years) who underwent mitral valve surgery from January 2010 to December 2011 were studied. In addition to standard echocardiography, baseline three-dimensional echocardiography was performed for accurate quantification of LV size. Patients were followed over a median time of 1 month (interquartile range, 0-8 months) for postoperative development of atrial fibrillation or LV dysfunction. A multivariate regression analysis was performed to identify associations with events.</AbstractText>Postoperative LV dysfunction developed in 15 patients (22%), and 21 patients (31%) had postoperative atrial fibrillation. There was no association between two-dimensional end-systolic volume index and outcomes (hazard ratio, 1.02; P = .18). Postoperative atrial fibrillation or LV dysfunction was associated with baseline three-dimensional LV end-systolic volume index (hazard ratio, 1.06; 95% confidence interval, 1.04-1.16), independent of age and presence of coronary artery disease. LVESVi ≥ 40 mL/m(2) was the best cutoff value to predict postoperative events (sensitivity, 80%; specificity, 85%). After adding LVESVi to a model containing clinical and echocardiographic parameters, net reclassification improvement was 0.27 (95% confidence interval, 0.25-0.29; P = .024).</AbstractText>LVESVi from three-dimensional echocardiography is an independent predictor of postoperative outcomes in patients with severe mitral regurgitation that is incremental to other clinical and echocardiographic variables.</AbstractText>Copyright © 2014 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
11,998 | Continuously adjusting CRT therapy: clinical impact of adaptive cardiac resynchronization therapy. | Cardiac resynchronization therapy (CRT) is a well-established therapy to reduce morbidity and mortality in patients with moderate and severe symptomatic congestive heart failure. Left ventricular (LV) pacing that fuses with intrinsic right ventricular (RV) conduction results in similar or even better cardiac performance compared to biventricular (Biv) pacing. Optimal programming of the atrio-ventricular (AV) and inter-ventricular (VV) delays is crucial to improve LV performance since suboptimal programming of AV and VV delays affect LV filling as well as cardiac output. CRT optimization using echocardiogram is resource-dependent and time consuming. Adaptive CRT (aCRT) algorithm provides a dynamic, automatic, ambulatory adjustment of CRT pacing configuration (Biv or LV pacing) and optimization of AV and VV delays. aCRT algorithm is safe and efficacious for CRT-indicated patients without permanent atrial fibrillation. It has been shown to improve CRT response and reduce morbidity and mortality for patients with normal AV conduction. |
11,999 | Mitral valve repair versus replacement in patients with ischaemic mitral regurgitation and depressed ejection fraction: risk factors for early and mid-term mortality†. | Mitral valve (MV) surgery for ischaemic mitral regurgitation (IMR) in patients with depressed left ventricular ejection fraction (LVEF) is associated with poor outcomes. The optimal surgical strategy for IMR in these patients remains controversial. The objective of this study was to compare the early mortality and mid-term survival of MV repair versus MV replacement in patients with IMR and depressed LVEF undergoing coronary artery bypass grafting (CABG).</AbstractText>A retrospective, observational, cohort study was undertaken of prospectively collected data on 126 consecutive CABG patients with IMR and LVEF <40% undergoing either MV repair (n = 98, 78%) or MV replacement (n = 28, 22%) between July 2002 and February 2011.</AbstractText>The overall mortality rate was 7.9% (n = 10). MV replacement was associated with a 4-fold increase in the risk of death compared with MV repair [17.9%, n = 5 vs 5.1%, n = 5; odds ratio (OR) 4.04, 95% confidence interval (CI) 1.08-15.1, P = 0.04]. However, after adjusting for preoperative risk factors, the type of surgical procedure was not an independent risk factor for early mortality (OR 0.1, 95% CI 0.01-31, P = 0.7). Multivariable analysis showed that preoperative LVEF (OR 0.8, 95% CI 0.6-0.9, P = 0.018), preoperative B-type natriuretic peptide (BNP) levels (OR 1.01, 95% CI 1-1.02, P = 0.025), preoperative left ventricle end-systolic diameter (OR 0.8, 95% CI 0.7-1.0, P = 0.05) and preoperative left atrial diameter (OR 1.3, 95% CI 1.0-1.6, P = 0.015) were independent risk factors of early mortality. At the median follow-up of 45 months (interquartile range 20-68 months), the mid-term survival rate was 74% in the MV repair group and 70% in the MV replacement group (P = 0.08). At follow-up, predictors of worse survival were BNP levels [hazard ratio (HR) 1.0, 95% CI 1.0-1.01, P = 0.047], preoperative renal failure (HR 4.6, 95% CI 1.1-20.3, P = 0.039) and preoperative atrial fibrillation (HR 3.3, 95% CI 1.1-10, P = 0.032).</AbstractText>MV repair in CABG patients with IMR and depressed LVEF is not superior to MV replacement with regard to operative early mortality and mid-term survival.</AbstractText>© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.</CopyrightInformation> |
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