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12,500 | Simultaneous double coronary thrombosis in a 47-year-old male patient with acute myocardial infarction. | Male, 47 FINAL DIAGNOSIS: Acute myocardial infarction Symptoms: Chest pain Medication: - Clinical Procedure: - Specialty: Cardiology.</AbstractText>Unusual clinical course.</AbstractText>Double myocardial infarction involving two culprit major vessels is a rarely reported presentation with high incidence of mortality.</AbstractText>In this study, we report 47-year-old male patient who had an attack of chest pain associated with ST-segment elevation in the antero-lateral leads. Pharmaco-invasive reperfusion approach was adopted with full dose tissue plasminogen activator, followed by transferring the patient to a specialized heart center for Percutaneous Coronary Intervention (PCI). Coronary angiography showed a fresh thrombus totally occluding Left Anterior Descending (LAD) and another thrombus causing distal total occlusion of a dominant Right Coronary Artery (RCA). Two Bare metal stents were placed in both lesions with Thrombolysis in Myocardial Infarction (TIMI) 3 flow post dilatation, but the patient, unfortunately, went into Ventricular Fibrillation (VF) followed by asystole and died 35 minutes later.</AbstractText>Acute double vessel coronary artery thrombosis is a serious event that requires prompt diagnosis and management to prevent its complications.</AbstractText> |
12,501 | Dual-site right ventricular and left ventricular pacing in a patient with left ventricular systolic dysfunction and atrial fibrillation using a standard CRT-D device. | In patients undergoing cardiac resynchronization therapy with defibrillator (CRT-D) implantation for left ventricular systolic dysfunction (LVSD) accompanied by permanent atrial fibrillation (AF), generally, the unused atrial port is plugged at device implantation. We describe an alternative use for the atrial-port in this case report. A 43 year old gentleman with LVSD due to left ventricular non-compaction (LVNC) and AF of unknown duration underwent a CRT-D implantation after optimization of cardiac failure treatment. The atrial-port which would otherwise have been plugged was connected to a high right ventricular septal (RVS) pacing-lead and the shock-lead was positioned at the right ventricular apex (RVA). This approach permitted modified cardiac resynchronization in a high RVS to left ventricular (LV) and RVA pacing sequence using the high RVS and LV pacing combined with a shock vector including the RV apex. A standard CRT-D device with a minimum programmable A-V delay of 30 ms (technically RVS to LV delay in the 'DDD' pacing mode) was used. The device was programmed to a 'DDD' pacing mode (sequential multi-site ventricular pacing with some programmability). The mode switch operation was programmed 'OFF' since atrial sensing is unavailable. Device-delivered shocks did not cardiovert the patient back to sinus rhythm suggesting that the AF was permanent (no prior cardioversion attempts were made on the presumption that the chances of maintaining sinus rhythm, given the underlying cardiac condition, were low). Subsequently, the patient required radio-frequency ablation of the atrio-ventricular node for conducted AF. Symptomatic, echocardiographic and radiological improvement preceded atrio-ventricular node ablation.</AbstractText>Amongst AF patients with permanent AF undergoing CRT-D implantation, those patients who are likely to have the CRT-D device atrial-ports plugged could benefit from having both the options of (i) a RVA shock vector as well as (ii) a high RVS-pacing feasible, by utilizing the atrial-port of a conventional CRTD device for a RVS pacing lead, should a RVA shock-lead position be preferred. New device programming algorithms will be necessary to make patient-customized programming in this lead configuration flexible, more useful clinically and easy.</AbstractText> |
12,502 | Left ventricular diastolic function is associated with symptom status in severe aortic valve stenosis. | In aortic valve stenosis (AS), the occurrence of heart failure symptoms does not always correlate with severity of valve stenosis and left ventricular (LV) function. Therefore, we tested the hypothesis that symptomatic patients with AS have impaired diastolic, longitudinal systolic function, and left atrial dilatation compared with asymptomatic patients.</AbstractText>In a retrospective descriptive study, we compared clinical characteristics and echocardiographic parameters in 99 symptomatic and 139 asymptomatic patients with severe AS and LV ejection fraction ≥50%. Independent predictors of symptomatic state were identified using logistic regression analysis. Symptomatic patients were younger (72±10 versus 76±12 years of age; P=0.002), presented less often with atrial fibrillation (13% versus 24%; P=0.05) and chronic obstructive pulmonary disease (2% versus 19%; P<0.001), and had a lower prevalence of hypertension (73% versus 40%; P<0.001). Despite similar AS severity, symptomatic patients had higher LV mass index (120±39 versus 95±25 g/m2; P<0.0001), increased relative wall thickness (0.61±0.15 versus 0.50±0.11; P<0.0001), shorter mitral deceleration time (199±58 versus 268±62 ms; P<0.0001), and increased left atrial volume index (49±18 versus 42±15 mL/m2; P=0.02). When adjusting for age, history of hypertension, atrial fibrillation, and chronic obstructive pulmonary disease in a multivariable logistic regression analysis, LV mass index, relative wall thickness, left atrial volume index, and deceleration time were still associated with the presence of symptoms.</AbstractText>The present study demonstrates that symptomatic status in severe AS is associated with impaired diastolic function, LV hypertrophy, concentric remodeling, and left atrial dilatation when corrected for indices of AS severity.</AbstractText>URL: http://www.clinicaltrials.gov. Unique identifier: NCT00294775.</AbstractText> |
12,503 | Experimental cardiac arrest treatment with adrenaline, vasopressin, or placebo. | The effect of vasoconstrictors in prolonged cardiopulmonary resuscitation (CPR) has not been fully clarified.</AbstractText>To evaluate adrenaline and vasopressin pressure effect, and observe the return of spontaneous circulation (ROSC).</AbstractText>A prospective, randomized, blinded, and placebo-controlled study. After seven minutes of untreated ventricular fibrillation, pigs received two minutes cycles of CPR. Defibrillation was attempted (4 J/kg) once at 9 minutes, and after every cycle if a shockable rhythm was present, after what CPR was immediately resumed. At 9 minutes and every five minutes intervals, 0.02 mg/kg (n = 12 pigs) adrenaline, or 0.4 U/kg (n = 12) vasopressin, or 0.2 mL/kg (n = 8) 0.9% saline solution was administered. CPR continued for 30 minutes or until the ROSC.</AbstractText>Coronary perfusion pressure increased to about 20 mmHg in the three groups. Following vasoconstrictors doses, pressure level reached 35 mmHg versus 15 mmHg with placebo (p < 0.001). Vasopressin effect remained at 15-20 mmHg after three doses versus zero with adrenaline or placebo. ROSC rate differed (p = 0.031) among adrenaline (10/12), vasopressin (6/12), and placebo (2/8). Time-to-ROSC did not differ (16 minutes), nor the number of doses previously received (one or two). There was no difference between vasoconstrictors, but against placebo, only adrenaline significantly increased the ROSC rate (p = 0.019).</AbstractText>The vasoconstrictors initial pressure effect was equivalent and vasopressin maintained a late effect at prolonged resuscitation. Nevertheless, when compared with placebo, only adrenaline significantly increased the ROSC rate.</AbstractText> |
12,504 | Preferred tools and techniques for implantation of cardiac electronic devices in Europe: results of the European Heart Rhythm Association survey. | The aim of this European Heart Rhythm Association (EHRA) survey was to assess clinical practice in relation to the tools and techniques used for cardiac implantable electronic devices procedures in the European countries. Responses to the questionnaire were received from 62 members of the EHRA research network. The survey involved high-, medium-, and low-volume implanting centres, performing, respectively, more than 200, 100-199 and under 100 implants per year. The following topics were explored: the side approach for implantation, surgical techniques for pocket incision, first venous access for lead implantation, preference of lead fixation, preferred coil number for implantable cardioverter-defibrillator (ICD) leads, right ventricular pacing site, generator placement site, subcutaneous ICD implantation, specific tools and techniques for cardiac resynchronization therapy (CRT), lead implantation sequence in CRT, coronary sinus cannulation technique, target site for left ventricular lead placement, strategy in left ventricular lead implant failure, mean CRT implantation time, optimization of the atrioventricular (AV) and ventriculo-ventricular intervals, CRT implants in patients with permanent atrial fibrillation, AV node ablation in patients with permanent AF. This panoramic view allows us to find out the operator preferences regarding the techniques and tools for device implantation in Europe. The results showed different practices in all the fields we investigated, nevertheless the survey also outlines a good adherence to the common standards and recommendations. |
12,505 | Weather and triggering of ventricular arrhythmias in patients with implantable cardioverter-defibrillators. | Outdoor ambient weather has been hypothesized to be responsible for the seasonal distribution of cardiac arrhythmias. Because people spend most of their time indoors, we hypothesized that weather-related arrhythmia risk would be better estimated using an indoor measure or an outdoor measure that correlates well with indoor conditions, such as absolute humidity. The clinical records of 203 patients in eastern Massachusetts, USA, with an implantable cardioverter-defibrillator were abstracted for arrhythmias between 1995 and 2002. We used case-crossover methods to examine the association between weather and ventricular arrhythmia (VA). Among 84 patients who experienced 787 VAs, lower estimated indoor temperature (odds ratio (OR)=1.16, 95% confidence interval (CI) 1.05-1.27 for a 1 °C decrease in the 24-h average) and lower absolute humidity (OR=1.06, 95% CI 1.03-1.08 for a 0.5 g/m(3) decrease in the 96-h average) were associated with increased risk. Lower outdoor temperature increased risk only in warmer months, likely attributable to the poor correlation between outdoor and indoor temperature during cooler months. These results suggest that lower temperature and drier air are associated with increased risk of VA onset among implantable cardioverter-defibrillator patients. |
12,506 | Does atrial pacing lead to atrial fibrillation in patients with sick sinus syndrome? Insights from the DANPACE trial. | Paroxysmal atrial fibrillation (AF) is common in patients with sick-sinus syndrome (SSS) and pacemakers leading to morbidity and an increased risk of stroke or death. Previous studies indicate that atrial pacing may precipitate AF. We investigated the relation between atrial pacing and the occurrence of AF during long-term follow-up among patients with SSS, no prior AF, and dual-chamber pacemakers (DDDRs).</AbstractText>We analysed data from 396 patients who received DDDR pacemakers in the DANPACE trial. The percentage of atrial pacing (%AP) was compared with the number of mode-switch (MS) episodes collected by the pacemaker at each follow-up as an indicator of AF. Mean follow-up was 4.2 ± 2.4 years. The mean proportion of atrial and ventricular pacing was 59 ± 31 and 65 ± 33%, respectively. Approximately 72% developed AF as indicated by MS episodes at some point during follow-up. Unadjusted regression analysis indicated a relation between %AP and AF (P = 0.04), but after adjustment for possible confounders (sex, age, hypertension, diabetes, myocardial infarction, PQ interval, and left atrial diameter) there was no significant relationship (P = 0.37).</AbstractText>Atrial fibrillation is very common among patients with SSS. No association between %AP and development of AF was found in patients with SSS. Future trials may randomize patients to different levels of AP exposure.</AbstractText> |
12,507 | Relations of plasma total and high-molecular-weight adiponectin to new-onset heart failure in adults ≥65 years of age (from the Cardiovascular Health study). | Adiponectin exhibits cardioprotective properties in experimental studies, but elevated levels have been linked to increased mortality in older adults and patients with chronic heart failure (HF). The adipokine's association with new-onset HF remains less well defined. The aim of this study was to investigate the associations of total and high-molecular weight (HMW) adiponectin with incident HF (n = 780) and, in a subset, echocardiographic parameters in a community-based cohort of adults aged ≥65 years. Total and HMW adiponectin were measured in 3,228 subjects without prevalent HF, atrial fibrillation or CVD. The relations of total and HMW adiponectin with HF were nonlinear, with significant associations observed only for concentrations greater than the median (12.4 and 6.2 mg/L, respectively). After adjustment for potential confounders, the hazard ratios per SD increment in total adiponectin were 0.93 (95% confidence interval 0.72 to 1.21) for concentrations less than the median and 1.25 (95% confidence interval 1.14 to 1.38) higher than the median. There was a suggestion of effect modification by body mass index, whereby the association appeared strongest in participants with lower body mass indexes. Consistent with the HF findings, higher adiponectin tended to be associated with left ventricular systolic dysfunction and left atrial enlargement. Results were similar for HMW adiponectin. In conclusion, total and HMW adiponectin showed comparable relations with incident HF in this older cohort, with a threshold effect of increasing risk occurring at their median concentrations. High levels of adiponectin may mark or mediate age-related processes that lead to HF in older adults. |
12,508 | Usefulness of N-terminal pro-B-type natriuretic Peptide increase as a marker for cardiac arrhythmia in patients with syncope. | B-type natriuretic peptides (BNPs) have been investigated as biomarkers for risk stratification of patients with syncope. Their concentration can be influenced by age and co-morbidities. In the present study, we compared the change in N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels within 6 hours in patients with vasovagal and arrhythmic syncope to determine whether this change can predict arrhythmic syncope. Using a case-control design, 33 patients were enrolled. Of the 33 patients, 18 with arrhythmic syncope, as they underwent controlled ventricular tachycardia or ventricular fibrillation (VF) during device safety testing of an implantable cardioverter defibrillator implantation or battery replacement, were compared with 15 patients, who during a tilt-table test were diagnosed with vasovagal syncope (VS). For each patient, a blood sample for NT-proBNP evaluation was collected at baseline and 6 hours after the episode of ventricular tachycardia, VF, or VS. We calculated the percentage of increase in the 6-hour NT-proBNP concentration between the 2 groups using nonparametric techniques. We also calculated the area under a receiver operating characteristic curve with the 95% confidence intervals. The 6-hour change in the NT-proBNP concentrations between patients who had had an episode of ventricular tachycardia or VF and patients with VS was significantly different, with a median increase of 32% in the ventricular tachycardia or VF group versus 5% in the VS group (p <0.01). The area under a receiver operating characteristic curve to predict arrhythmic syncope was 0.8 (95% confidence interval 0.65 to 0.95). In conclusion, the results of the present study suggest that a 6-hour NT-proBNP increase might be able to predict arrhythmic syncope. Future work is needed to confirm these findings in undifferentiated emergency department patients who present with syncope. |
12,509 | Novel mitral clipping technique overcoming extreme atrial dilatation. | The mitral clipping technique is emerging as a promising new treatment option for severe mitral regurgitation. The device was designed and assessed in intermediate risk populations, which is in contrast to the real world, where most patients are deemed to be at very high risk for open heart surgery. The cardiac anatomy of these patients often challenges the freedom grades of the current mitral clip device. In this case presentation, we describe a novel technique overcoming extreme atrial dilation in a patient with severe mitral regurgitation despite previous implantation of two mitral clips. Based on a low/anterior trans-septal puncture, this procedure relied on a counter clock-wise 90° turn of the steerable sheath and alignment of the clip delivery system to the mitral valve, thereby gaining additional longitudinal freedom. This resulted in the successful implantation of two additional clips with achievement of a mild to moderate mitral regurgitation without relevant gradient and dramatic and sustained clinical improvement of the patient. |
12,510 | Silent cerebral infarcts associated with cardiac disease and procedures. | The occurrence of clinically silent cerebral infarcts (SCIs) in individuals affected by cardiac disease and after invasive cardiac procedures is frequently reported. Indeed, atrial fibrillation, left ventricular thrombus formation, cardiomyopathy, and patent foramen ovale have all been associated with SCIs. Furthermore, postprocedural SCIs have been observed after left cardiac catheterization, transcatheter aortic valve implantation, CABG surgery, pulmonary vein isolation, and closure of patent foramen ovale. Such SCIs are often described as precursors to symptomatic stroke and are associated with cognitive decline, dementia, and depression. Increased recognition of SCIs might advance our understanding of their relationship with heart disease and invasive cardiac procedures, facilitate further improvement of therapies or techniques aimed at preventing their occurrence and, therefore, decrease the risk of adverse neurological outcomes. In this Review, we provide an overview of the occurrence and clinical significance of, and the available diagnostic modalities for, SCIs related to cardiac disease and associated invasive cardiac procedures. |
12,511 | Is health-related quality of life a predictor of hospitalization or mortality among women or men with atrial fibrillation? | Little is known about predictors of mortality or hospitalization in women compared with men in patients with atrial fibrillation (AF). Although there are established gender differences in patients with coronary artery disease (CAD), differences have not been established in AF.</AbstractText>The aim of this study was to examine clinical and health-related quality of life (HRQOL) predictors of mortality and 1-year hospitalization in women compared with men with AF.</AbstractText>Limited-use data from the National Institutes of Health/National Heart, Lung, and Blood Institute Atrial Fibrillation Follow-up Investigation of Rhythm Management clinical trial provided the sample of 693 patients with AF, 262 women and 431 men. Clinical predictors examined were heart failure (HF), CAD, left ventricular ejection fraction, diabetes, stroke, and age. Predictors of HRQOL included overall HRQOL (Medical Outcomes Study Short Form-36 physical [PCS] and mental component scores) and cardiovascular HRQOL using Quality of Life Index-Cardiac Version.</AbstractText>Mortality did not differ (women, 11.4%; men, 14.5%; χ(2)1 = 0.437, P = .509) according to gender, with mean 3.5-year follow-up. Different variables independently predicted mortality for women and men. For women, diabetes (hazard ratio [HR], 3.415; P = .003), HF (HR, 2.346; P = .027), stroke (HR, 2.41; P = .032), and age (HR, 1.117; P = .002), and for men, CAD (HR, 1.914; P = 02), age (HR, 1.103, P = < .001), worse PCS (HR, 1.089, P = .001), and worse Quality of Life Index-Cardiac Version score (HR, 1.402, P = .025) independently predicted mortality.One-year hospitalization (women, 38.9%; men, 36.4%) did not differ by gender (χ(2)1 = 0.914, P = .339). Different variables independently predicted 1-year hospitalization-for women: diabetes (odds ratio [OR], 2.359; P = .022), worse PCS (OR, 1.070; P = .003), and rhythm control trial arm (OR, 2.111; P = .006); for men: HF (OR, 2.072; P = .007), worse PCS (OR, 1.045; P = .019), living alone (OR, 1.913; P = .036), and rhythm control trial arm (OR, 2.113; P < .001).</AbstractText>Only clinical status predicted mortality among women; HRQOL and clinical status predicted mortality among men. Both clinical and HRQOL variables predicted hospitalization for women and men. Increased monitoring of HRQOL and interventions designed to target the clinical and HRQOL predictors could impact mortality and hospitalization. Nursing interventions may prove effective for modifying most of the predictors of mortality and hospitalization for women and men with AF.</AbstractText> |
12,512 | Detection of atrial electrical and mechanical dysfunction in non-dipper pre-hypertensive subjects. | A relationship between atrial conduction time and hypertension was shown in previous studies. Increased atrial electromechanical intervals used to predict atrial fibrillation by measured tissue Doppler imaging (TDI). So we aimed to search if there was any association between the non-dipping status and atrial electromechanical intervals in pre-hypertensive patients.</AbstractText>Forty-one non-dipper and 33 dipper pre-hypertensive subjects enrolled in the study. Systolic and diastolic blood pressures were measured with a mercury sphygmomanometer. Twenty-four hours blood pressure was measured with cuff-oscillometric method. All patients were evaluated by transthoracic echocardiography. Using tissue Doppler imaging (TDI), atrial electromechanical coupling (PA) was measured from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septum) and right ventricular tricuspid annulus (PA tricuspid).</AbstractText>Systolic and diastolic blood pressures were significantly higher in subjects with non-dipper phenomenon than dipper ones at night. Twenty-four hours average systolic and diastolic blood pressures were higher in non-dipper pre-hypertensive subjects, but this elevation was not significant. Left and right intraatrial (PA lateral-PA septum and PA septum-PA tricuspid) and interatrial (PA lateral-PA tricuspid) electromechanical coupling intervals were measured significantly higher in non-dipper pre-hypertensive patients (31.3 ± 3.9 versus 24.1 ± 2.3, p = 0.001; 19.5 ± 4.3 versus 13.8 ± 2.1, p = 0.001; and 11.4 ± 2.8 versus 8.8 ± 1.5, p = 0.001). Also, interatrial electromechanical delay was negatively correlated with dipping levels.</AbstractText>This study showed that prolonged atrial electromechanical intervals were related non-dipper pattern in pre-hypertensive patients. Prolonged electromechanical intervals may be an early sign of subclinical atrial dysfunction and arrhythmias' in non-dipper pre-hypertensive patients.</AbstractText> |
12,513 | Impact of atrial fibrillation on exercise capacity in heart failure with preserved ejection fraction: a RELAX trial ancillary study. | Atrial fibrillation (AF) is common among patients with heart failure and preserved ejection fraction (HFpEF), but its clinical profile and impact on exercise capacity remain unclear. RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in HFpEF) was a multicenter randomized trial testing the impact of sildenafil on peak VO2 in stable outpatients with chronic HFpEF. We sought to compare clinical features and exercise capacity among patients with HFpEF who were in sinus rhythm (SR) or AF.</AbstractText>RELAX enrolled 216 patients with HFpEF, of whom 79 (37%) were in AF, 124 (57%) in SR, and 13 in other rhythms. Participants underwent baseline cardiopulmonary exercise testing, echocardiogram, biomarker assessment, and rhythm status assessment before randomization. Patients with AF were older than those in SR but had similar symptom severity, comorbidities, and renal function. β-blocker use and chronotropic indices were also similar. Despite comparable left ventricular size and mass, AF was associated with worse systolic (lower EF, stroke volume, and cardiac index) and diastolic (shorter deceleration time and larger left atria) function compared with SR. Pulmonary artery systolic pressure was higher in AF. Patients with AF had higher N-terminal pro-B-type natriuretic peptide, aldosterone, endothelin-1, troponin I, and C-telopeptide for type I collagen levels, suggesting more severe neurohumoral activation, myocyte necrosis, and fibrosis. Peak VO2 was lower in AF, even after adjustment for age, sex, and chronotropic response, and VE/VCO2 was higher.</AbstractText>AF identifies an HFpEF cohort with more advanced disease and significantly reduced exercise capacity. These data suggest that evaluation of the impact of different rate or rhythm control strategies on exercise tolerance in patients with HFpEF and AF is warranted.</AbstractText>URL: http://www.clinicaltrials.gov. Unique identifier: NCT00763867.</AbstractText> |
12,514 | Therapeutic strategy using extracorporeal life support, including appropriate indication, management, limitation and timing of switch to ventricular assist device in patients with acute myocardial infarction. | The appropriate indication for, management of and limitations to extracorporeal life support (ECLS) and the timing of a switch to a ventricular assist device (VAD) remain controversial issues in patients with acute myocardial infarction (AMI) complicated with cardiogenic shock or cardiopulmonary arrest. To evaluate and discuss these issues, we studied patients with AMI treated with ECLS and compared deceased and discharged patients. Thirty-eight patients with AMI who needed ECLS [35 men (92.1 %), aged 59.9 ± 13.5 years] were enrolled in this study. Of these 38 patients, 34 subsequently underwent percutaneous coronary intervention (PCI), and four subsequently received coronary artery bypass grafting (CABG). Fourteen patients (36.8 %) were discharged from the hospital. The outcome was not favorable for those patients with deteriorating low output syndrome (LOS) and the development of leg ischemia, hemolysis and multiple organ failure during ECLS. Levels of creatine kinase, creatine kinase-MB (CK-MB), lactate dehydrogenase, serum creatinine (Cr) and amylase after the patient had been put on ECLS and fluctuation of the cardiac index, blood pressure, arterial blood gas analysis and CK-MB and Cr levels during ECLS were indicators to switch from the ECLS to VAD. In the case of patients with no complication associated with ECLS, 4.6-5.6 days after initiation of ECLS was assumed to be the threshold to decide whether to switch from ECLS to VAD. Patients with AMI who suddenly developed refractory pulseless ventricular tachycardia or ventricular fibrillation without deteriorating LOS and who underwent successful PCI or CABG, and who prevented the complications associated with ECLS, showed a high probability of recovering with ECLS. |
12,515 | Cardiopulmonary involvement in Puumala hantavirus infection. | Hantavirus infections cause potentially life-threatening disease in humans world-wide. Infections with American hantaviruses may lead to hantavirus pulmonary syndrome characterised by severe cardiopulmonary distress with high mortality. Pulmonary involvement in European Puumala hantavirus (PUUV) infection has been reported, whereas knowledge of potential cardiac manifestations is limited. We aimed to comprehensively investigate cardiopulmonary involvement in patients with PUUV-infection.</AbstractText>Twenty-seven hospitalised patients with PUUV-infection were examined with lung function tests, chest high-resolution CT (HRCT), echocardiography including speckle tracking strain rate analysis, ECG and measurements of cardiac biomarkers N-terminal pro-B-type natriuretic peptide (NT-ProBNP) and troponin T. Patients were re-evaluated after 3 months. Twenty-five age and sex-matched volunteers acted as controls for echocardiography data.</AbstractText>Two-thirds of the patients experienced respiratory symptoms as dry cough or dyspnoea. Gas diffusing capacity was impaired in most patients, significantly improving at follow-up but still subnormal in 38%. HRCT showed thoracic effusions or pulmonary oedema in 46% of the patients. Compared to controls, the main echocardiographic findings in patients during the acute phase were significantly higher pulmonary vascular resistance, higher systolic pulmonary artery pressure, lower left ventricular ejection fraction and impaired left atrial myocardial motion. Pathological ECG, atrial fibrillation or T-wave changes, was demonstrated in 26% of patients. NT-ProBNP concentrations were markedly increased and were inversely associated with gas diffusing capacity but positively correlated to pulmonary vascular resistance. Furthermore, patients experiencing impaired general condition at follow-up had significantly lower gas diffusing capacity and higher pulmonary vascular resistance, compared to those feeling fully recovered.</AbstractText>In a majority of patients with PUUV-infection, both cardiac and pulmonary involvement was demonstrated with implications on patients' recovery. The results demonstrate vascular leakage in the lungs that most likely is responsible for impaired gas diffusing capacity and increased pulmonary vascular resistance with secondary pulmonary hypertension and right heart distress. Interestingly, NT-ProBNP was markedly elevated even in the absence of overt ventricular heart failure. The method of simultaneous investigations of important cardiac and respiratory measurements improves the interpretation of the underlying pathophysiologic mechanisms.</AbstractText> |
12,516 | [Immune status of patients with persistent atrial fibrillation and coronary heart disease]. | We estimated the strength of immune response to chlamydial infection in patients with CHD. It was most pronounced in CHD patients with atrial fibrillation (AF). There was close relationship between past chlamydial infection and markers of inflammation (CRP and TNF-alpha). The study demonstrated high prognostic value of these markers for the development of AF during CHD and their relationship with characteristics of structural and functional remodeling of myocardium during CHD with AF. The study confirmed the role of inflammation in pathogenesis of AF in CHD patients. |
12,517 | Prevention of atrial fibrillation by bucindolol is dependent on the beta₁389 Arg/Gly adrenergic receptor polymorphism. | This study assessed the impact of bucindolol, a beta-blocker/sympatholytic agent, on the development of atrial fibrillation (AF) in advanced chronic heart failure with reduced left ventricular ejection fraction (HFREF) patients enrolled in the BEST (Beta-Blocker Evaluation of Survival Trial).</AbstractText>β-blockers have modest efficacy for AF prevention in HFREF patients. Bucindolol's effects on HF and ventricular arrhythmic endpoints are genetically modulated by β₁- and α(2c)-adrenergic receptor (AR) polymorphisms that can be used to subdivide HFREF populations into those with bucindolol effectiveness levels that are enhanced, unchanged, or lost.</AbstractText>BEST enrolled 2,708 New York Heart Association (NYHA) class III to IV HFREF patients. A substudy in which 1,040 patients' DNA was genotyped for the β₁-AR position 389 Arg/Gly and the α(2c)322-325 wild type (Wt)/deletion (Del) polymorphisms, and new-onset AF was assessed from adverse event case report forms or electrocardiograms at baseline and at 3 and 12 months.</AbstractText>In the entire cohort, bucindolol reduced the rate of new-onset AF compared to placebo by 41% (hazard ratio [HR]: 0.59 [95% confidence interval (CI): 0.44 to 0.79], p = 0.0004). In the 493 β₁389 arginine homozygotes (Arg/Arg) in the DNA substudy, bucindolol reduced new-onset AF by 74% (HR: 0.26 [95% CI: 0.12 to 0.57]), with no effect in β₁389 Gly carriers (HR: 1.01 [95% CI: 0.56 to 1.84], interaction test = 0.008). When β₁389 Gly carriers were subdivided by α(2c) Wt homozygotes (n = 413, HR: 0.94 [95% CI: 0.48 to 1.82], p = 0.84) or Del variant carriers (n = 134, HR: 1.33 [95% CI: 0.32 to 5.64], p = 0.70), there was a positive interaction test (p = 0.016) when analyzed with β₁389 Arg homozygotes.</AbstractText>Bucindolol prevented new-onset AF; β₁ and α(2c) polymorphisms predicted therapeutic response; and the 47% of patients who were β₁389 Arg homozygotes had an enhanced effect size of 74%. (Beta-Blocker Evaluation in Survival Trial [BEST]; NCT00000560)</AbstractText> |
12,518 | A century of optocardiography. | In the past decade, optical mapping provided crucial mechanistic insight into electromechanical function and the mechanism of ventricular fibrillation. Therefore, to date, optical mapping dominates experimental cardiac electrophysiology. The first cardiac measurements involving optics were done in the early 1900s using the fast cinematograph that later evolved into methods for high-resolution activation and repolarization mapping and stimulation of specific cardiac cell types. The field of "optocardiography," therefore, emerged as the use of light for recording or interfering with cardiac physiology. In this review, we discuss how optocardiography developed into the dominant research technique in experimental cardiology. Furthermore, we envision how optocardiographic methods can be used in clinical cardiology. |
12,519 | Mechanical ventilation during cardiopulmonary resuscitation with intermittent positive-pressure ventilation, bilevel ventilation, or chest compression synchronized ventilation in a pig model. | Mechanical ventilation with an automated ventilator is recommended during cardiopulmonary resuscitation with a secured airway. We investigated the influence of intermittent positive-pressure ventilation, bilevel ventilation, and the novel ventilator mode chest compression synchronized ventilation, a pressure-controlled ventilation triggered by each chest compression, on gas exchange, hemodynamics, and return of spontaneous circulation in a pig model.</AbstractText>Animal study.</AbstractText>University laboratory.</AbstractText>Twenty-four three-month-old female domestic pigs.</AbstractText>The study was performed on pigs under general anesthesia with endotracheal intubation. Arterial and central venous catheters were inserted and IV rocuronium (1 mg/kg) was injected. After 3 minutes of cardiac arrest (ventricular fibrillation at t = 0 min), animals were randomized into intermittent positive-pressure ventilation (control group), bilevel, or chest compression synchronized ventilation group. Following 10 minute uninterrupted chest compressions and mechanical ventilation, advanced life support was performed (100% O2, up to six defibrillations, vasopressors).</AbstractText>Blood gas samples were drawn at 0, 4 and 13 minutes. At 13 minutes, hemodynamics was analyzed beat-to-beat in the end-inspiratory and end-expiratory cycle comparing the IPPV with the bilevel group and the CCSV group. Data were analyzed with the Mann-Whitney U test. Return of spontaneous circulation was achieved in five of eight (intermittent positive-pressure ventilation), six of eight (bilevel), and four of seven (chest compression synchronized ventilation) pigs. The results of arterial blood gas analyses at t = 4 minutes and t = 13 minutes (torr) were as follows: PaO2 intermittent positive-pressure ventilation, 143 (76/256) and 262 (81/340); bilevel, 261 (109/386) (p = 0.195 vs intermittent positive-pressure ventilation) and 236 (86/364) (p = 0.878 vs intermittent positive-pressure ventilation); and chest compression synchronized ventilation, 598 (471/650) (p < 0.001 vs intermittent positive-pressure ventilation) and 634 (115/693) (p = 0.054 vs intermittent positive-pressure ventilation); PaCO2 intermittent positive-pressure ventilation, 40 (38/43) and 45 (36/52); bilevel, 39 (35/41) (p = 0.574 vs intermittent positive-pressure ventilation) and 46 (42/49) (p = 0.798); and chest compression synchronized ventilation, 28 (27/32) (p = 0.001 vs intermittent positive-pressure ventilation) and 26 (18/29) (p = 0.004); mixed venous pH intermittent positive-pressure ventilation, 7.34 (7.31/7.35) and 7.26 (7.25/7.31); bilevel, 7.35 (7.29/7.37) (p = 0.645 vs intermittent positive-pressure ventilation) and 7.27 (7.17/7.31) (p = 0.645 vs intermittent positive-pressure ventilation); and chest compression synchronized ventilation, 7.34 (7.33/7.39) (p = 0.189 vs intermittent positive-pressure ventilation) and 7.35 (7.34/7.36) (p = 0.006 vs intermittent positive-pressure ventilation). Mean end-inspiratory and end-expiratory arterial pressures at t = 13 minutes (mm Hg) were as follows: intermittent positive-pressure ventilation, 28.0 (25.0/29.6) and 27.9 (24.4/30.0); bilevel, 29.1 (25.6/37.1) (p = 0.574 vs intermittent positive-pressure ventilation) and 28.7 (24.2/36.5) (p = 0.721 vs intermittent positive-pressure ventilation); and chest compression synchronized ventilation, 32.7 (30.4/33.4) (p = 0.021 vs intermittent positive-pressure ventilation) and 27.0 (24.5/27.7) (p = 0.779 vs intermittent positive-pressure ventilation).</AbstractText>Both intermittent positive-pressure ventilation and bilevel provided similar oxygenation and ventilation during cardiopulmonary resuscitation. Chest compression synchronized ventilation elicited the highest mean arterial pressure, best oxygenation, and a normal mixed venous pH during cardiopulmonary resuscitation.</AbstractText> |
12,520 | Shorter minimum p-wave duration is associated with paroxysmal lone atrial fibrillation. | Prolonged P-wave dispersion (PWD) and P-wave duration (PWdur) have been found to be associated with common atrial fibrillation (AF), but the association of P-wave indices with lone atrial fibrillation (LAF) is unclear.</AbstractText>We enrolled 61 paroxysmal LAF cases and 150 controls without AF. P-wave indices were measured from a 12-lead ECG. Multivariable logistic regression was used to assess the association between P-wave indices and LAF.</AbstractText>PWD was longer in LAF patients (median, IQR; 54.1 [42.9-63.2] ms) than controls (46.0 [38.5-57.7] ms), P=0.03. MinPWdur was shorter in LAF patients (60.5 [50.7-72.6] ms) than controls (66.0 [55.5-76.4] ms), P=0.03. In multivariable models, only the association between shorter minPWdur and LAF remained statistically significant (OR [95% CI] per tertile increment in minPWdur, 0.64 [0.42-0.95], P=0.03).</AbstractText>Unlike common AF, paroxysmal LAF is independently associated with shorter minPWdur. This finding suggests that both shorter and prolonged PWdur may be associated with increased risk of AF.</AbstractText>© 2013.</CopyrightInformation> |
12,521 | Altered cardiac electrophysiology and SUDEP in a model of Dravet syndrome. | Dravet syndrome is a severe form of intractable pediatric epilepsy with a high incidence of SUDEP: Sudden Unexpected Death in epilepsy. Cardiac arrhythmias are a proposed cause for some cases of SUDEP, yet the susceptibility and potential mechanism of arrhythmogenesis in Dravet syndrome remain unknown. The majority of Dravet syndrome patients have de novo mutations in SCN1A, resulting in haploinsufficiency. We propose that, in addition to neuronal hyperexcitability, SCN1A haploinsufficiency alters cardiac electrical function and produces arrhythmias, providing a potential mechanism for SUDEP.</AbstractText>Postnatal day 15-21 heterozygous SCN1A-R1407X knock-in mice, expressing a human Dravet syndrome mutation, were used to investigate a possible cardiac phenotype. A combination of single cell electrophysiology and in vivo electrocardiogram (ECG) recordings were performed.</AbstractText>We observed a 2-fold increase in both transient and persistent Na(+) current density in isolated Dravet syndrome ventricular myocytes that resulted from increased activity of a tetrodotoxin-resistant Na(+) current, likely Nav1.5. Dravet syndrome myocytes exhibited increased excitability, action potential duration prolongation, and triggered activity. Continuous radiotelemetric ECG recordings showed QT prolongation, ventricular ectopic foci, idioventricular rhythms, beat-to-beat variability, ventricular fibrillation, and focal bradycardia. Spontaneous deaths were recorded in 2 DS mice, and a third became moribund and required euthanasia.</AbstractText>These data from single cell and whole animal experiments suggest that altered cardiac electrical function in Dravet syndrome may contribute to the susceptibility for arrhythmogenesis and SUDEP. These mechanistic insights may lead to critical risk assessment and intervention in human patients.</AbstractText> |
12,522 | Insulinoma presenting with cardiac arrest and cardiomyopathy. | A 33-year-old woman presented with ventricular fibrillation cardiac arrest and was found to have a blood glucose of 1.83 mmol/L. Cardiac catheterisation revealed a dilated left ventricle with an ejection fraction (EF) of 26% and angiographically normal coronary arteries. Continuous dextrose infusion was required to treat hypoglycaemia, which prompted consideration of insulinoma as a possible cause for her cardiomyopathy. Whipple's triad was demonstrated; a 72 h fast provided biochemical evidence of insulinoma, and imaging localised a tumour in her pancreas. The tumour was resected and pathology confirmed insulinoma; pancreaticoduodenectomy cured her hypoglycaemia. No alternate cause of cardiomyopathy was found and 4 months after surgery her EF improved to 41%. High insulin levels can close cardiac K(ATP) channels associated with dilated cardiomyopathy; the catecholamine surge from hypoglycaemia may also contribute to ventricular remodelling. Hypoglycaemia can cause QT segment prolongation, and may have precipitated fibrillation in this patient's arrhythmia-prone myocardium. |
12,523 | Remote monitoring of a high-risk patient with Brugada syndrome: association of different arrhythmic manifestations. | We report on the remote arrhythmia monitoring of a 34-year-old man with highly symptomatic Brugada syndrome, who initially presented with syncope, paroxysmal atrial fibrillation, and spontaneous coved-type electrocardiogram. The patient received a dual-chamber implantable cardioverter-defibrillator (ICD) with Home Monitoring™ facilities and experienced recurrent ICD shocks for spontaneous ventricular fibrillation (VF) episodes during the first year after ICD implantation. Remote monitoring revealed an increased burden of premature ventricular complexes and atrial arrhythmias each time VF spontaneously occurred. Atrial and ventricular arrhythmias were effectively suppressed by low-dose quinidine without severe side effects. |
12,524 | [The ICD in the terminal stage]. | ICDs are used to prevent sudden death caused by ventricular fibrillation. The number of patients with an ICD will keep growing. ICD shocks can severely disturb the dying process in terminally ill patients. Patients must be informed about this at the time of ICD implantation. The attending physician is responsible for proactive communication regarding deactivation when death is expected imminently. The decision to deactivate the ICD depends on personal wishes, and has proved to be difficult even if the patient has been well informed. Deactivation at home must be available so that severely ill patients do not need to travel to a hospital. |
12,525 | Differential clinical characteristics and prognosis of patients with longstanding persistent atrial fibrillation presenting with recurrent atrial tachycardia versus recurrent atrial fibrillation after first ablation. | It is unknown if baseline characteristics and prognosis of patients with longstanding persistent (defined as history greater than 1 year) atrial fibrillation (LS-AF) differ among those with either recurrent atrial tachycardia (R-AT) or recurrent AF (R-AF) after first ablation.</AbstractText>In 222 consecutive LS-AF patients treated for R-AT or R-AF after first ablation, activation and entrainment mapping was used to identify R-AT mechanism and to guide the following ablation, and the ablation endpoints for all patients included complete pulmonary vein isolation, bidirectional block of lines, and disappearance of complex fractionated atrial electrograms.</AbstractText>There were 102 patients in the R-AF group. LS-AF patients with R-AT as compared to R-AF had shorter AF duration and recurrence interval, smaller left atrium size and left ventricular end-diastolic diameter, and less mitral and aortic regurgitation before first ablation. During follow-up (17.7 ± 4.0 months) after R-AT/R-AF ablation, 78 LS-AF patients developed recurrent atrial tachyarrhythmia, with lower overall and recurrence as AF in R-AT versus R-AF groups.</AbstractText>LS-AF patients who develop R-AT versus R-AF after first ablation have more favorable baseline characteristics and prognosis.</AbstractText>© 2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,526 | Long-term outcomes of early surgery for asymptomatic severe chronic mitral regurgitation. | The long-term outcomes of early surgery in patients with asymptomatic severe chronic mitral regurgitation (MR) and the impact of preoperative left ventricular dysfunction, atrial fibrillation (AF) and/or pulmonary hypertension (PH) on outcomes in this patient group, were evaluated.</AbstractText>Between 1992 and 2007, a total of 212 patients (mean age 50 +/- 15 years) with asymptomatic severe chronic degenerative MR underwent early mitral valve surgery within 12 months after echocardiographic diagnosis at the authors' institution. Mitral valve repair was attempted in all cases. The mean follow up period was 82 +/- 36 months. The patients were allocated to two groups; 111 with preoperative left ventricular dysfunction, AF and/or PH (group A), and 101 patients without those findings (group B). The outcomes were compared using univariate and multivariate analyses.</AbstractText>Mitral valve repair was performed successfully in 211 patients (99.5%). The operative mortality was 0.5% (1/212). The 10-year actuarial survivals were 97.3% in all patients, 95.1% in group A, and 100% in group B. The 10-year cardiac adverse event-free rates (cardiac death, mitral valve reoperation or readmission with congestive heart failure) were 94.7% in all patients, 92.7% in group A, and 96.2% in group B. The seven-year freedom rates from recurrent MR were 93.1% in all patients, 90.0% in group A, and 97.0% in group B. In comparative analyses, group A had poorer late outcomes than group B, although the differences were not statistically significant. The multivariate analysis failed to show that preoperative left ventricular dysfunction, AF and/or PH were significantly associated with late cardiac adverse event (HR: 2.1, 95% CI: 0.4 to 10.8; p = 0.392).</AbstractText>Early surgery for asymptomatic chronic MR demonstrated excellent early and late outcomes. The study results failed to confirm that preoperative left ventricular dysfunction, AF and/or PH were significantly associated with adverse outcomes of early mitral valve surgery in this patient group.</AbstractText> |
12,527 | Global longitudinal strain in patients with suspected heart failure and a normal ejection fraction: does it improve diagnosis and risk stratification? | Many patients have clinical, structural or bio-marker evidence of heart failure (HF) but a normal left ventricular ejection fraction (LVEF; HeFNEF). Measurement of global longitudinal strain (GLS) may add diagnostic and prognostic information. Patients with symptoms suggesting heart failure and LVEF ≥50% were studied: 76 had no substantial cardiac dysfunction (left atrial diameter (LAD) <40 mm and amino-terminal pro-brain natriuretic peptide (NTproBNP) <400 ng/l); 99 had "possible HeFNEF" (LAD ≥40 mm or NTproBNP ≥400 ng/l); and 138 had "definite HeFNEF" (LAD ≥40 mm and NTproBNP ≥400 ng/L). Mean LVEF was 58% in each subgroup. Patients with definite HeFNEF were older, more likely to have atrial fibrillation, had more symptoms and signs of fluid retention, were more likely to have right ventricular dysfunction and had higher pulmonary pressures than other groups. Mean GLS (SD) was less negative in patients with definite HeFNEF (-13.6 (3.0)% vs. possible HeFNEF: -15.2 (3.1)% vs. no substantial cardiac dysfunction: -15.9 (2.4)%; p < 0.001). GLS was -19.1 (2.1)% in 20 controls. During a median follow up of 647 days, cardiovascular death or an unplanned hospitalisation for heart failure occurred in 62 patients. In univariable analysis, GLS but not LVEF predicted events. However, in a multi-variable analysis, only urea, NTproBNP, left atrial volume, inferior vena cava diameter and atrial fibrillation independently predicted adverse outcome. GLS is abnormal in patients who have other evidence of HeFNEF, is associated with a worse prognosis in this population but is not a powerful independent predictor of outcome. |
12,528 | Temporal variation and morphologic characteristics of J-waves in patients with early repolarisation syndrome. | Electrocardiographic markers identifying malignant forms of early repolarisation (ER) from ER of normal variants are of prime clinical importance. We compared the ECG parameters of ER patterns in patients with early repolarisation syndrome (ERS) proximate to the ventricular fibrillation (VF) episodes, remote from the events and those with normal controls with ER.</AbstractText>A retrospective, case-control study.</AbstractText>University hospital.</AbstractText>This study included 12 patients with ERS and 36 age-matched, gender-matched controls with ER.</AbstractText>Dynamic change of J-wave.</AbstractText>The highest amplitude of J-wave, sum of the J-wave amplitudes or the number of leads with ER showed a dramatic change during the perievent period. J-wave amplitudes (2.0±1.3 vs 4.0±1.7, p=0.004) and the number of leads with ER (3.3±1.7 vs 5.3±2.0, p=0.021) were significantly higher around the time of VF. In particular, the characteristic morphology of 'giant' (wide, >80 ms) J-waves were observed during the perievent period in 5/12 patients with ERS. However, there were no significant differences in the electrocardiographic parameters of ER pattern remote from VF events between the patients with ERS and normal control subjects with ER.</AbstractText>Although the extent of and amplitude of J-wave or ST segment elevation (STE) increased significantly around VF episodes, the electrocardiographic parameters of ER remote from VF episodes were not significantly different from those of normal controls. The narrow time window of these ECG changes limits early detection of ER patients at risk of developing VF or sudden cardiac death.</AbstractText> |
12,529 | A de novo novel cardiac ryanodine mutation (Ser4155Tyr) associated with catecholaminergic polymorphic ventricular tachycardia. | We describe the case of a 14-year-old girl with a history of syncopal episodes triggered by stress or exercise. Catecholaminergic polymorphic ventricular tachycardia was diagnosed with the aid of an implantable loop recorder. The genetic testing of the patient and her family revealed a de novo novel missense mutation (Ser4155Tyr) in the exon 90 of the ryanodine receptor gene. This mutation affects a highly conserved residue (S4155) and results to replacement of serine (S) with tyrosine (Y) leading to change in physical and chemical properties. The girl was treated with an implantable defibrillator, metoprolol and flecainide. Over 1 year of follow-up she had no recurrence of ventricular tachycardia. |
12,530 | Prolonged therapeutic hypothermia is more effective in attenuating brain apoptosis in a Swine cardiac arrest model. | To investigate whether 48 hours of therapeutic hypothermia is more effective to attenuate brain apoptosis than 24 hours and to determine whether the antiapoptotic effects of therapeutic hypothermia are associated with the suppressions of the cleavage of protein kinase C-δ, the cytosolic release of cytochrome c, and the cleavage of caspase 3 in a swine cardiac arrest model.</AbstractText>Prospective laboratory study.</AbstractText>University laboratory.</AbstractText>Male domestic pigs (n = 24).</AbstractText>After 6 minutes of no-flow time that was induced by ventricular fibrillation, cardiopulmonary resuscitation was provided, and the return of spontaneous circulation was achieved. The animals were randomly assigned to the following groups: sham, normothermia, 24 hours of therapeutic hypothermia, or 48 hours of therapeutic hypothermia. Therapeutic hypothermia (core temperature, 32-34°C) was maintained for 24 or 48 hours post return of spontaneous circulation, and the animals were rewarmed for 8 hours. At 60 hours post return of spontaneous circulation, the animals were killed, and brain tissues were harvested.</AbstractText>We examined cellular apoptosis and neuronal damage in the brain hippocampal cornu ammonis 1 region. We also measured the cleavage of protein kinase C-δ, the cytosolic release of cytochrome c, and the cleavage of caspase 3 in the hippocampus. The 48 hours of therapeutic hypothermia attenuated cellular apoptosis and neuronal damage when compared with normothermia. There was also a decrease in the cleavage of protein kinase C-δ, the cytosolic release of cytochrome c, and the cleavage of caspase 3. However, 24 hours of therapeutic hypothermia did not significantly attenuate cellular apoptosis or neuronal damage.</AbstractText>We found that 48 hours of therapeutic hypothermia was more effective in attenuating brain apoptosis than 24 hours of therapeutic hypothermia. We also found that the antiapoptotic effects of therapeutic hypothermia were associated with the suppressions of the cleavage of protein kinase C-δ, the cytosolic release of cytochrome c, and the cleavage of caspase 3.</AbstractText> |
12,531 | Diastolic function assessed from tagged MRI predicts heart failure and atrial fibrillation over an 8-year follow-up period: the multi-ethnic study of atherosclerosis. | The strain relaxation index (SRI), a novel diastolic functional parameter derived from tagged magnetic resonance imaging (MRI), is used to assess myocardial deformation during left ventricular relaxation. We investigated whether diastolic function indexed by SRI predicts heart failure (HF) and atrial fibrillation (AF) over an 8-year follow-up.</AbstractText>As a part of the multi-ethnic study of atherosclerosis, 1544 participants free of known cardiovascular disease (CVD) underwent tagged MRI in 2000-02. Harmonic phase analysis was used to compute circumferential strain. Standard parameters, early diastolic strain rate (EDSR) and the peak torsion recoil rate were calculated. An SRI was calculated as difference between post-systolic and systolic times of the strain peaks, divided by the EDSR peak. It was normalized by the total interval of relaxation. Over an 8-year follow-up period, we defined AF (n = 57) or HF (n = 36) as combined (n = 80) end-points. Cox regression assessed the ability of SRI to predict events adjusted for risk factors and markers of subclinical disease. Integrated discrimination index (IDI) and net reclassification index (NRI) of SRI, compared with conventional indices, were also assessed.</AbstractText>The hazard ratio for SRI remained significant for the combined HF and AF end-points as well as for HF alone after adjustment. For the combined end-point, IDI was 1.5% (P < 0.05) and NRI was 11.4% (P < 0.05) for SRI. Finally, SRI was more robust than all other existing cardiovascular magnetic resonance diastolic functional parameters.</AbstractText>SRI predicts HF and AF over an 8-year follow-up period in a large population free of known CVD, independent of established risk factors and markers of subclinical CVD.</AbstractText> |
12,532 | Implantable intravascular defibrillator: defibrillation thresholds of an intravascular cardioverter-defibrillator compared with those of a conventional ICD in humans. | A percutaneous intravascular cardioverter-defibrillator (PICD) has been developed with a right ventricular (RV) single-coil lead and titanium electrodes in the superior vena cava (SVC)-brachiocephalic vein (BCV) region and the inferior vena cava (IVC).</AbstractText>To compare defibrillation thresholds (DFTs) of the PICD with those of a conventional ICD in humans.</AbstractText>Ten patients with ischemic cardiomyopathy and ejection fraction ≤35% were randomized to initial testing with either PICD or conventional ICD. A standard dual-coil lead was positioned in the RV apex. If randomized to PICD, the device was placed into the vasculature such that 1 titanium electrode was positioned in the SVC-BCV region and the second in the IVC. For PICD DFTs, the RV coil of the conventional ICD lead was connected to the PICD mandrel [shock vector: RV (+) to SVC-BCV (-) + IVC (-)]. When testing the conventional ICD, a subcutaneous pocket was formed in the left pectoralis region and the ICD was connected to the lead system and positioned in the pocket [shock vector: RV (+) to SVC (-) + active can (-)]. Each device was removed before testing with the other. A step-down binary search protocol determined the DFT, with the initial shock being 9 J.</AbstractText>The mean PICD DFT was 7.6 ± 3.3 J, and the conventional ICD system demonstrated a mean DFT of 9.5 ± 4.7 J (N = 10; paired t test, P = .28).</AbstractText>The intravascular defibrillator has DFTs similar to those of commercially available ICDs.</AbstractText>Published by Heart Rhythm Society on behalf of Heart Rhythm Society.</CopyrightInformation> |
12,533 | TGF-β1 signal pathway in the regulation of inflammation in patients with atrial fibrillation. | To observe the expression changes of inflammatory markers TGF-β1, Smad3 and IL-6 in patients with atrial fibrillation (AF), and to explore the significance of TGF-β1 signaling pathway in the structural remodeling of AF.</AbstractText>The expression of TGF-β1, Smad3 and IL-6 in 50 cases with AF and 30 normal cases were detected by RT-PCR and ELISA.</AbstractText>The TGF-β1, Smad3 and IL-6 mRNA and protein expression levels in patients with AF were significantly higher than that in the control group (P<0.05), but there was no significantly different between the paroxysmal AF group and the persistent AF group (P>0.05). The TGF-β1mRNA expression in the ⩾ 50 years subgroup was significantly higher than that in the <50 years subgroups, and it was higher in the NYHA III subgroup than in the I/II grade subgroup. It was also higher in the left ventricular ejection fraction (LVEF) <50% subgroup than in LVEF ⩾ 50% group, and it was significantly higher in the AF time ⩾ 36 months subgroup than that in <36 months subgroup (P<0.05). The Smad3 and IL-6 expressions in the in the LVEF <50% subgroup were both high that than that in LVEF ⩾ 50% group, and higher in the AF time ⩾ 36 months subgroup than that in <36 months subgroup (P<0.05). There were a positive correlation between TGF-β1, Smad3 and IL-6 (r=0.687, r=0.547). There were also a positive correlation between Smad3 and IL-6 mRNA (r=0.823).</AbstractText>AF is associated with inflammation, and the inflammation is also involved in the fibrillation and sustain of AF. The TGF-β1 signal pathway may be involved in the process of atrial structural remodeling in patients with AF, and iss related with the occurrence and maintenance of AF.</AbstractText>Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.</CopyrightInformation> |
12,534 | Periatrial epicardial fat is associated with markers of endothelial dysfunction in patients with atrial fibrillation. | Epicardial adipose tissue (EAT) is associated to atrial fibrillation (AF) burden and outcome after AF ablation. We intended to determine whether global or local EAT is associated with systemic and/or left atrial (LA) inflammation and markers of endothelial dysfunction in AF patients.</AbstractText>Total, atrial, and ventricular EAT volume (EAT total, EAT atrial, EAT ventricular) were measured by multislice cardiac CT in 49 patients with paroxysmal (PAF, n=25) or persistent AF (PeF, n=24). Periatrial epicardial fat thickness at the esophagus (LA-ESO) and thoracic aorta (LA-ThA) were also measured. Vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), soluble intercellular adhesion molecule 1 (sICAM-1), transforming growth factor-β1 (TGF-β1), and von Willebrand Factor (vWF) levels were measured in peripheral and LA blood samples obtained during catheterization during AF ablation. Patients with PeF had higher EAT atrial (P<0.05) and LA-ESO (P=0.04) than patients with PAF. VEGF, IL-8, and TGF-β1 were not associated with EAT. In contrast, after adjusting for LA volume and body mass index, higher LA-ThA was significantly associated with higher sICAM-1 and vWF levels, both in peripheral blood (P<0.05) and in LA (P<0.05). Similar results were found with LA-ESO. Body mass index, EAT total and EAT ventricular were not associated with sICAM-1 and vWF.</AbstractText>Periatrial epicardial fat showed a significant positive association with increased levels of sICAM-1 and vWF, which are biomarkers of endothelial dysfunction. No such associations were found when considering body mass index or EAT total. These results suggest that local EAT rather than regional or total adiposity may modulate endothelial dysfunction in patients with AF.</AbstractText> |
12,535 | Inequalities in heart failure in older men: prospective associations between socioeconomic measures and heart failure incidence in a 10-year follow-up study. | Socioeconomic position has been linked to incident heart failure (HF), but the underlying mechanisms are unclear. We examined the association of socioeconomic measures with incident HF in older adults and examined possible underlying pathways.</AbstractText>A socially representative cohort of men aged 60-79 years in 1998-2000 from 24 British towns was followed-up for 10 years for incident HF. Adult socioeconomic position was based on a cumulative score, including occupation, education, housing tenure, pension, and amenities. Childhood socioeconomic measures included father's occupational social class and household amenities. Prevalent myocardial infarction and HF cases were excluded. Among 3836 men, 229 incident cases of HF occurred over 10 years. Heart failure risk increased with an increasing score of adverse adult socioeconomic measures (P for trend = < 0.0001). Compared with men with a score of 0, the hazard ratio for men with a score of ≥ 4 was 2.19 (95% confidence interval, CI, 1.34-3.55), which was attenuated to 1.87 (95% CI 1.12-3.11) after adjusting for systolic blood pressure, body mass index, smoking, HDL-cholesterol, diabetes, and lung function. Adjustment for left ventricular hypertrophy, atrial fibrillation, heart rate, and renal function made little difference. Further adjustment for C-reactive protein, von Willebrand Factor, N-terminal pro-brain natriuretic peptide, and plasma vitamin C also made little difference to the hazard ratio [1.89 (95% CI 1.10-3.24)]. Heart failure risk did not vary by childhood socioeconomic measures.</AbstractText>Heart failure risk in older men was greater in the most deprived socioeconomic groups, which was only partly explained by established risk factors for HF. Novel risk factors contribute little to the associated risk.</AbstractText> |
12,536 | Ulinastatin attenuates oxidation, inflammation and neural apoptosis in the cerebral cortex of adult rats with ventricular fibrillation after cardiopulmonary resuscitation. | The role of Ulinastatin in neuronal injury after cardiopulmonary resuscitation has not been elucidated. We aim to evaluate the effects of Ulinastatin on inflammation, oxidation, and neuronal injury in the cerebral cortex after cardiopulmonary resuscitation.</AbstractText>Ventricular fibrillation was induced in 76 adult male Wistar rats for 6 min, after which cardiopulmonary resuscitation was initiated. After spontaneous circulation returned, the rats were split into two groups: the Ulinastatin 100,000 unit/kg group or the PBS-treated control group. Blood and cerebral cortex samples were obtained and compared at 2, 4, and 8 h after return of spontaneous circulation. The protein levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were assayed using an enzyme-linked immunosorbent assay, and mRNA levels were quantified via real-time polymerase chain reaction. Myeloperoxidase and Malondialdehyde were measured by spectrophotometry. The translocation of nuclear factor-κB p65 was assayed by Western blot. The viable and apoptotic neurons were detected by Nissl and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL).</AbstractText>Ulinastatin treatment decreased plasma levels of TNF-α and IL-6, expression of mRNA, and Myeloperoxidase and Malondialdehyde in the cerebral cortex. In addition, Ulinastatin attenuated the translocation of nuclear factor-κB p65 at 2, 4, and 8 hours after the return of spontaneous circulation. Ulinastatin increased the number of living neurons and decreased TUNEL-positive neuron numbers in the cortex at 72 h after the return of spontaneous circulation.</AbstractText>Ulinastatin preserved neuronal survival and inhibited neuron apoptosis after the return of spontaneous circulation in Wistar rats via attenuation of the oxidative stress response and translocation of nuclear factor-κB p65 in the cortex. In addition, Ulinastatin decreased the production of TNF-α, IL-6, Myeloperoxidase, and Malondialdehyde.</AbstractText> |
12,537 | Proteomics discovery of biomarkers for mitral regurgitation caused by mitral valve prolapse. | Mitral regurgitation (MR) is a common valvular lesion frequently caused by mitral valve prolapse (MVP). Surgical intervention in MVP patients with significant MR is predicated on symptoms and measures of left ventricular dysfunction. Because these indicators may be subjective or imprecise, serological biomarkers of disease could be a valuable adjunct to standard evaluation. This study aimed to identify such biomarkers by a proteomics approach. Two pooled plasma samples from 24 MVP subjects with MR (MVP/MR) and 24 non-MVP individuals were treated with the combinatorial peptide ligand library (CPLL) beads prior to iTRAQ labeling and ESI-MS/MS. Lower levels of haptoglobin, platelet basic protein (PBP), and complement component C4b were observed in the MVP/MR as compared to the control sample. These findings were verified by ELISA testing of each of the 24 paired samples, and another 42 matched cases and controls. The AUC values, sensitivities and specificities for (i) haptoglobin, (ii) PBP, (iii) C4b, and (iv) all 3 proteins in combination were (i) 0.813, 76%, 74%; (ii) 0.721, 56%, 77%; (iii) 0.689, 83%, 49%; and (iv) 0.840, 89%, 67%, respectively. In conclusion, haptoglobin, PBP, and C4b are down-regulated in MVP/MR. Their value as serological biomarkers of valvular pathology should be further explored.</AbstractText>We report the first study that performed comparative proteomics of clinical human plasma samples to identify novel diagnostic biomarkers for mitral valve prolapse (MVP) patients with moderate to severe mitral regurgitation (MR). MR is a common valvular lesion that can be complicated by heart failure, sudden death and atrial fibrillation, yet many patients with severe MR are asymptomatic. Our results revealed reduced levels of haptoglobin, platelet basic protein (PBP), and complement component C4b in the MVP/MR patients as compared to the matched control cases. The plasma proteomics findings were subsequently confirmed by ELISA. Each of these candidate biomarkers has a putative role in the pathophysiology of MVP/MR, further supporting their roles in detection and possibly surveillance and prognostication of this disease.</AbstractText>© 2013.</CopyrightInformation> |
12,538 | Characterization of predictors of in-hospital cardiac complications of takotsubo cardiomyopathy: multi-center registry from Tokyo CCU Network. | Takotsubo cardiomyopathy (TC) is an acute cardiac syndrome characterized by transient left ventricular dysfunction and relatively good prognosis after discharge. However, cardiac complications during hospitalization remain to be fully determined. We attempted to determine features characterizing patients with adverse clinical outcome by comparing those with cardiac complication and without cardiac complication during hospitalization.</AbstractText>We investigated 107 patients with TC from the Tokyo CCU Network database, comprising 67 cardiovascular centers in the metropolitan area during January 1 to December 31, 2010. Cardiac complications were defined as cardiac death, pump failure (Killip grade≥II), sustained ventricular tachycardia or fibrillation (SVT/VF), and advanced atrioventricular block (AVB). Cardiac complications were observed in 41 patients (37 pump failure complicated by 3 cardiac deaths and 2 SVT/VF and 2 AVB without pump failure), and there was no cardiac complication in the remaining 66 patients. There was no difference in age, peak creatinine kinase level, C-reactive protein level and ST elevation on electrocardiogram. Multiple logistic regression analysis showed that white blood cell count (p=0.039) and brain natriuretic peptide (p=0.001) were independent predictors of in-hospital adverse cardiac complications.</AbstractText>Cardiac complications are relatively high in patients with TC during hospitalization. High white blood cell count and brain natriuretic peptide level are associated with poor clinical outcome in patients with TC.</AbstractText>Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
12,539 | Polymorphic ventricular tachycardia-part I: structural heart disease and acquired causes. | Polymorphic ventricular tachycardia (PMVT) is an unusual ventricular tachyarrhythmia. Perhaps its most unique characteristic is a continuously evolving QRS morphology. Although the most common substrate for PMVT is structural heart disease, the prevalence of sudden cardiac death in the population without structural heart disease is even greater, and the absence of a myocardial substrate would suggest that PMVT is the anticipated cause of sudden cardiac death in this population as well. Mechanistically, PMVT is distinct from ventricular fibrillation. It appears to be a condition of abnormal repolarization and resultant cellular heterogeneities, and the principles of triggering and reentry have been demonstrated to govern its initiation and maintenance. The "channelopathies"-a growing category of inherited or acquired conditions that predispose to PMVT and sudden cardiac death-present a fascinating challenge with potentially dire consequences as there are few indicators of their existence except for subtle, if any, electrocardiographic changes. The ever-expanding number of pharmaceuticals that affect ion channel function further magnifies this risk. |
12,540 | Left atrial volumes and associated stroke subtypes. | Cardio embolism and cerebrovascular atherosclerosis are two major mechanisms of stroke. Studies investigating associations between advanced echocardiographic parameters and stroke mechanisms are limited.</AbstractText>This study is a standardized review of 633 patients admitted to the stroke service of a tertiary care hospital following a standardized stroke investigation and management pathway. Stroke subtypes were characterized using the Causative Classification System, using the hospitals online radiologic archival system with CCS certified stroke investigators. Patients with two mechanisms were excluded.</AbstractText>Patients with cardioembolic stroke had a higher proportion of atrial fibrillation (p < 0.001), acute myocardial infarction (p < 0.001) and ischemic heart disease (p < 0.001). On electrocardiogram (ECG) and transthoracic Echo (TTE), patients with cardioembolic stroke had a greater atrial fibrillation (p < .00), left ventricular thrombus (p < .00), left ventricular ejection fraction <30% (p < .00) and global hypokinesia (p < .00) Patients with cardioembolic stroke had higher mean left atrial volume indices (LAVi) (p < 0.001), mean left ventricular mass indices (LVMi) (p < 0.05) and mean left atrial diameters (LAD) (p < 0.05). At LAVi of 29-33 ml/m2, the risk of atherothrombotic stroke increased. The risk of cardioembolic stroke increased with LAVi of 34 ml/m2 and above.</AbstractText>Left atrial volume indices may be linked to specific stroke phenotype. At mild increases in left atrial dimensions, the risks of atherosclerotic stroke are high, and probably reflect hypertension as the unifying mechanism. Further increases in left atrial dimensions shifts the risk towards cardioembolic stroke.</AbstractText> |
12,541 | Mastocytosis presenting as cardiac emergency. | Mastocytosis is characterised by clonal proliferation of mast cells in the skin and in various internal organs, and by symptoms related to an acute release of mast cell-derived mediators. In 20-30 % of patients, mastocytosis occurs without the typical skin lesions of urticaria pigmentosa that are usually the first clinical sign of the disease. In these patients, anaphylaxis is often the presenting sign of the disease. We report three cases in which a cardiac emergency (cardiac arrest or ventricular fibrillation) was the first clinical manifestation of anaphylaxis associated with systemic mastocytosis. All patients were men, none of them had previous episodes of anaphylaxis or other mediator-related symptoms, and none had major pre-existing cardiovascular condition. An eliciting factor was identified in one case (a wasp sting), but one was found in the other two. Elevation of the serum tryptase suggested a mastocytosis, which was confirmed by bone marrow biopsy. This case series demonstrates that cardiovascular emergencies may be presenting signs of mastocytosis, and that elevation of serum tryptase after an acute cardiac event, if confirmed under basal conditions, may be useful for diagnosing this disease. |
12,542 | Calcium channel blockers improve exercise capacity and reduce N-terminal Pro-B-type natriuretic peptide levels compared with beta-blockers in patients with permanent atrial fibrillation. | Rate control of atrial fibrillation (AF) has become a main treatment modality, but we need more knowledge regarding the different drugs used for this purpose. In this study, we aimed to compare the effect of four common rate-reducing drugs on exercise capacity and levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with permanent AF.</AbstractText>We included 60 patients (mean age 71 ± 9 years, 18 women) with permanent AF and normal left ventricular function in a randomized, cross-over, investigator-blind study. Diltiazem 360 mg, verapamil 240 mg, metoprolol 100 mg, and carvedilol 25 mg were administered o.d. for 3 weeks. At baseline and on the last day of each treatment period, the patients underwent a maximal cardiopulmonary exercise test and blood samples were obtained at rest and at peak exercise. The exercise capacity (peak VO2) was significantly lower during treatment with metoprolol and carvedilol compared with baseline (no treatment) or treatment with diltiazem and verapamil (P < 0.001 for all). Compared with baseline, treatment with diltiazem and verapamil significantly reduced the NT-proBNP levels both at rest and at peak exercise, whereas treatment with metoprolol and carvedilol increased the levels (P < 0.05 for all).</AbstractText>Rate-reducing treatment with diltiazem or verapamil preserved exercise capacity and reduced levels of NT-proBNP compared with baseline, whereas treatment with metoprolol or carvedilol reduced the exercise capacity and increased levels of NT-proBNP.</AbstractText> |
12,543 | Transthoracic epicardial ablation of mitral isthmus for treatment of recurrent perimitral flutter. | Perimitral flutter (PMF) is a common form of left atrial tachycardia after atrial fibrillation (AF) ablation. The mitral isthmus (MI) is the standard ablation target. However, in some cases bidirectional block cannot be achieved.</AbstractText>The purpose of this study was to describe the first experience using a transthoracic epicardial (TTE) approach to treat recurrent PMF after prior unsuccessful ablation.</AbstractText>This is a case series of four patients with recurrence of highly symptomatic drug-refractory PMF (all male, median age 55 years, 3/4 hypertensive, 2/4 persistent AF, median AF period 24 months). Three patients presented with PMF-related tachymyocardiopathy. TTE ablation of MI was performed after a median of two prior endocardial MI and coronary sinus ablation attempts, using an open-tip 3.5-mm irrigated catheter (40 W, 45ºC). Persistent bidirectional block was assessed by activation mapping and differential pacing and was achieved in all patients.</AbstractText>No PMF recurrence was observed after median follow-up of 18 months (range 15-22 months; two patients without antiarrhythmic drugs and two with previously ineffective amiodarone). Left ventricular function normalized in all three patients with tachycardiomyopathy. There were no complications related to TTE approach.</AbstractText>The present study is the first to report the feasibility of a TTE approach for highly symptomatic PMF refractory to endocardial and coronary sinus MI ablation.</AbstractText>© 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.</CopyrightInformation> |
12,544 | Propranolol prevents life-threatening arrhythmias in LQT3 transgenic mice: implications for the clinical management of LQT3 patients. | The efficacy of beta-blockers for treatment of patients with long QT syndrome type 3 (LQT3) has been repeatedly questioned, and it has been suggested that they might be detrimental for this genetic subgroup of patients with long QT syndrome (LQTS). The disquieting consequence has been that cardiologists confronted with LQT3 patients often do not even attempt pharmacologic therapy and implant cardioverter-defibrillators as first-choice treatment. However, the most recent clinical data indicate high efficacy of beta-blocker therapy in LQT3 patients.</AbstractText>The purpose of this study was to test the antiarrhythmic efficacy of beta-blockers in an established experimental model for LQT3.</AbstractText>After phenotypic validation of 65 ∆KPQ-SCN5A knock-in transgenic (TG) mice compared to 32 wild-type (WT) mice, we tested the effect of the arrhythmogenic cholinergic muscarinic agonist carbachol in 19 WT and 39 TG anesthetized mice, with and without pretreatment with propranolol given intraperitoneally.</AbstractText>At the same heart rates, TG mice had a markedly longer QT interval than WT mice. Whereas carbachol had minor arrhythmic effects in the WT mice, it produced ventricular tachycardia (VT) and ventricular fibrillation (VF) in 55% of 20 TG mice. By contrast, in none of 19 TG mice pretreated with propranolol did VT/VF occur after carbachol injection.</AbstractText>These experimental data indicate that, contrary to previous reports, beta-blockade effectively prevents VT/VF in a validated LQT3 model. Together with the most recent clinical data, these findings indicate that there is no reason for not initiating protective therapy with beta-blockers in LQT3 patients.</AbstractText>© 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.</CopyrightInformation> |
12,545 | Atrial fibrillation in heart failure: catheter and surgical interventional therapies. | Atrial fibrillation and heart failure commonly coexist in the same patient. Each may adversely affect the other. Atrial fibrillation leads to heart failure exacerbation, left ventricular function deterioration and an increase in thrombo-embolic risk. Therapeutic options targeting atrial fibrillation in heart failure patients include pharmacological and non-pharmacological means. Pharmacological therapy is directed at either rate control using nodal blocking agents or rhythm control using anti-arrhythmic agents, of which the options are limited in patients with heart failure. The landmark AF-CHF trial did not show any benefit of rhythm control strategy as opposed to rate control in patients with heart failure and atrial fibrillation. However, patients in this trial as well as in others used mostly amiodarone for rhythm control. This might have negated any positive effects of achieving normal sinus rhythm. Non-pharmacological therapy both for rate and rhythm control is appealing. This includes AV node ablation for rate control, catheter ablation of atrial fibrillation and surgical therapy of atrial fibrillation. This review will address non-pharmacologic treatment of AF in heart failure patients. |
12,546 | Comparison of cold crystalloid and colloid infusions for induction of therapeutic hypothermia in a porcine model of cardiac arrest. | Large-volume cold intravenous infusion of crystalloids has been used for induction of therapeutic hypothermia after cardiac arrest. However, the effectiveness of cold colloids has not been evaluated. Therefore, we performed an experimental study to investigate the cooling effect of cold normal saline compared to colloid solution in a porcine model of ventricular fibrillation.</AbstractText>Ventricular fibrillation was induced for 15 minutes in 22 anesthetized domestic pigs. After spontaneous circulation was restored, the animals were randomized to receive either 45 ml/kg of 1°C cold normal saline (Group A, 9 animals); or 45 ml/kg of 1°C cold colloid solution (Voluven, 6% hydroxyethyl starch 130/0.4 in 0.9% NaCl) during 20 minutes (Group B, 9 animals); or to undergo no cooling intervention (Group C, 4 animals). Then, the animals were observed for 90 minutes. Cerebral, rectal, intramuscular, pulmonary artery, and subcutaneous fat body temperatures (BT) were recorded. In the mechanical ex-vivo sub study we added a same amount of cold normal saline or colloid into the bath of normal saline and calculated the area under the curve (AUC) for induced temperature changes.</AbstractText>Animals treated with cold fluids achieved a significant decrease of BT at all measurement sites, whereas there was a consistent significant spontaneous increase in group C. At the time of completion of infusion, greater decrease in pulmonary artery BT and cerebral BT in group A compared to group B was detected (-2.1 ± 0.3 vs. -1.6 ± 0.2°C, and -1.7 ± 0.4 vs. -1.1 ± 0.3°C, p < 0.05, respectively). AUC analysis of the decrease of cerebral BT revealed a more vigorous cooling effect in group A compared to group B (-91 ± 22 vs. -68 ± 23°C/min, p = 0.046). In the mechanical sub study, AUC analysis of the induced temperature decrease of cooled solution revealed that addition of normal saline led to more intense cooling than colloid solution (-7155 ± 647 vs. -5733 ± 636°C/min, p = 0.008).</AbstractText>Intravenous infusion of cold normal saline resulted in more intense decrease of cerebral and pulmonary artery BT than colloid infusion in this porcine model of cardiac arrest. This difference is at least partially related to the various specific heat capacities of the coolants.</AbstractText> |
12,547 | Long-term follow-up after autologous skeletal myoblast transplantation in ischaemic heart disease. | Short-term follow-up after autologous skeletal myoblasts (ASM) transplantation (Tx) (Myoblast Autologous Grafting in Ischaemic Cardiomyopathy (MAGIC) Phase II Study) for the treatment of ischaemic cardiomyopathy revealed improved left ventricular (LV) remodelling. Our study reports the longest long-term worldwide follow-up of a single-centre cohort, focusing on the safety and efficacy of ASM-Tx.</AbstractText>The multicentre MAGIC Phase II Study involved 120 patients and was conducted between 2004 and 2006. Out of the 120 patients involved in the entire study, the cohort treated at our institution contained 7 patients only. These 7 patients received ASM-Tx (injection volume: 400 million cells, n = 2 low dosage; 800 million cells, n = 2 high dosage) or placebo (n = 3) injections, in addition to coronary artery bypass grafting (CABG). After closure of the MAGIC registry, we conducted a long-term follow-up for our 7-patient cohort. The mean follow-up was 72.0 ± 5.3 months. The follow-up was complete for echo data, implanted cardioverter defibrillator (ICD) report, clinical investigation and New York Heart Association (NYHA) class.</AbstractText>At final follow-up, all the patients were alive, and 5 were in NYHA class 1 or 2. There were 6 hospitalizations for congestive heart failure during the follow-up (1 patient from each group). One patient (placebo group) was treated twice for ventricular fibrillation by the ICD. The LV ejection fraction remained stable in all the three groups (31.1 ± 3.9% preoperative vs 29.4 ± 4.4% at final follow-up). The LV volumes were reduced in the high-dosage group, remained unchanged in the low-dosage group and deteriorated in the placebo group.</AbstractText>Our long-term data confirm the findings of the MAGIC study. The LV function did not improve, but the long-term LV volumes in the high-dosage group were reduced. During the follow-up, there were also no additional arrhythmogenic incidences. Our data could imply that CABG in combination with ASM-Tx is safe and has beneficial therapeutic effects in the long-term. However, due to the small patient number, the clinical impact is limited.</AbstractText> |
12,548 | [Comparison of different electrocardiographic techniques for the detection of arrhythmias in horses]. | The aim of the study was to extend the range of the electrocardiographic examination in horses, evaluating the practicability of special electrocardiographic techniques (exercise- and Holter-ECG) and comparing these with more common techniques (resting-ECG) in equine medicine.</AbstractText>Electrocardiographic examination (resting-ECG for 1 minute, exercise-ECG and Holter-ECG) was performed in 20 horses without any clinical or echocardiographic findings and in 80 patients with abnormal findings (valvular regurgitation and/or atrial fibrillation).</AbstractText>In comparison with the resting-ECG, the exercise-ECG demonstrated more atrial and ventricular premature beats, while the Holter-ECG had a higher detection rate of 2nd degree atrioventricular or sinuatrial blocks, and of ventricular and atrial premature depolarisations (p < 0.001). In comparison to the exercise-ECG, the Holter-ECG registered more 2nd degree atrioventricular blocks (p < 0.001) and ventricular (p < 0.001) or atrial premature contractions (p < 0.01). Atrial fibrillation was detected in every recorded ECG-type, but Holter-ECG provided additional information. Three of 16 horses with atrial fibrillation had R-on-T-episodes during Holter-monitoring. In addition to more common findings in the ECG, Holter-monitoring detected a 2nd degree atrioventricular block associated with an adjacent ventricular escape beat in a horse without any clinical or echocardiographic findings. An accelerated idioventricular rhythm was identified in a horse without any clinical or echocardiographic findings and in a horse with mitral valve insufficiency.</AbstractText>The Holter-ECG is a useful tool in the evaluation of heart disease and could supply additional information when compared to the usual diagnostic electrocardiographic procedures used in horses. Exercise-ECG should not be replaced by Holter-ECG, however, Holter-EGC can provide additional diagnostic value.</AbstractText> |
12,549 | Hypothermic liquid ventilation prevents early hemodynamic dysfunction and cardiovascular mortality after coronary artery occlusion complicated by cardiac arrest in rabbits. | Ultrafast and whole-body cooling can be induced by total liquid ventilation with temperature-controlled perfluorocarbons. Our goal was to determine whether this can afford maximal cardio- and neuroprotections through cooling rapidity when coronary occlusion is complicated by cardiac arrest.</AbstractText>Prospective, randomized animal study.</AbstractText>Academic research laboratory.</AbstractText>Male New Zealand rabbits.</AbstractText>Chronically instrumented rabbits were submitted to coronary artery occlusion and ventricular fibrillation. After 8 minutes of cardiac arrest, animals were resuscitated and submitted to a normothermic follow-up (control group) or to 3 hours of mild hypothermia induced by total liquid ventilation (total liquid ventilation group) or by combination of cold saline infusion and cold blankets application (saline group). Coronary reperfusion was permitted 40 minutes after the onset of occlusion. After awakening, rabbits were followed up during 7 days.</AbstractText>Ten animals were resuscitated in each group. In the control group, all animals secondarily died of cardiac/respiratory failure (8 of 10) or neurological dysfunction (2 of 10). In the saline group, the target temperature of 32°C was achieved within 30-45 minutes after cooling initiation. This slightly reduced infarct size versus control (41% ± 16% vs 54% ± 8% of risk zone, respectively; p < 0.05) but failed to significantly improve cardiac output, neurological recovery, and survival rate (three survivors, six death from cardiac/respiratory failure, and one from neurological dysfunction). Conversely, the 32°C temperature was achieved within 5-10 minutes in the total liquid ventilation group. This led to a dramatic reduction in infarct size (13% ± 4%; p < 0.05 vs other groups) and improvements in cardiac output, neurological recovery, and survival (eight survivors, two deaths from cardiac/respiratory failure).</AbstractText>Achieving hypothermia rapidly is critical to improve the cardiovascular outcome after cardiac arrest with underlying myocardial infarction.</AbstractText> |
12,550 | Identifiability of subgroup causal effects in randomized experiments with nonignorable missing covariates. | Although randomized experiments are widely regarded as the gold standard for estimating causal effects, missing data of the pretreatment covariates makes it challenging to estimate the subgroup causal effects. When the missing data mechanism of the covariates is nonignorable, the parameters of interest are generally not pointly identifiable, and we can only get bounds for the parameters of interest, which may be too wide for practical use. In some real cases, we have prior knowledge that some restrictions may be plausible. We show the identifiability of the causal effects and joint distributions for four interpretable missing data mechanisms and evaluate the performance of the statistical inference via simulation studies. One application of our methods to a real data set from a randomized clinical trial shows that one of the nonignorable missing data mechanisms fits better than the ignorable missing data mechanism, and the results conform to the study's original expert opinions. We also illustrate the potential applications of our methods to observational studies using a data set from a job-training program. |
12,551 | Outcomes of defibrillator therapy in catecholaminergic polymorphic ventricular tachycardia. | Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by adrenergically induced ventricular arrhythmias in patients with structurally normal hearts. Initiating triggered arrhythmias, such as bidirectional ventricular tachycardia, often degenerate into reentrant arrhythmias, such as ventricular fibrillation (VF).</AbstractText>To determine whether the effectiveness of implantable cardioverter-defibrillator (ICD) shocks is dependent on rhythm type.</AbstractText>It is a retrospective study of patients with CPVT who had undergone ICD implantation. Thirteen patients received ICDs (median age 15 years; range 9-43 years): 7 of 13 (54%) for cardiac arrest and 6 of 13 (46%) for syncope despite drug therapy. The median follow-up duration was 4.0 years (range 1.7-19.9 years). Nineteen reinterventions occurred, excluding generator replacements. Ten patients received 96 shocks (median 4 shocks; range 1-30 shocks). Eighty-seven shock electrograms were reviewed. Sixty-three (72%) shocks were appropriate, and 24 (28%) were inappropriate (T-wave oversensing 7 [29%], supraventricular arrhythmia 16 [67%], after self-terminating VF 1 [4%]).</AbstractText>Among appropriate shocks, 20 (32%) were effective in terminating sustained arrhythmia and 43 (68%) were ineffective. Shocks delivered to triggered arrhythmias nearly always failed (1 of 40 [3%] effective), while shocks delivered to VF were usually successful (19 of 23 [83%] effective; P < .001). Four patients received 17 appropriate antitachycardia pacing therapies for ventricular tachycardia: only 2 (12%) were effective. No patient died.</AbstractText>The effectiveness of ICD shock therapy in CPVT depends on the mechanism of the rhythm treated. Shocks delivered to initiating triggered arrhythmias nearly always fail, whereas those for subsequent VF are usually effective. ICD programming in these patients is exceptionally challenging.</AbstractText>© 2013 Published by Heart Rhythm Society on behalf of Heart Rhythm Society.</CopyrightInformation> |
12,552 | Candidate gene approach to identifying rare genetic variants associated with lone atrial fibrillation. | Rare variants in candidate atrial fibrillation (AF) genes have been associated with AF in small kindreds. The extent to which such polymorphisms contribute to AF is unknown.</AbstractText>The purpose of this study was to determine the spectrum and prevalence of rare amino acid coding (AAC) variants in candidate AF genes in a large cohort of unrelated lone AF probands.</AbstractText>We resequenced 45 candidate genes in 303 European American (EA) lone AF probands (186 lone AF probands screened for each gene on average [range 89-303], 63 screened for all) identified in the Vanderbilt AF Registry (2002-2012). Variants detected were screened against 4300 EAs from the Exome Sequencing Project (ESP) to identify very rare (minor allele frequency ≤0.04%) AAC variants and these were tested for AF co-segregation in affected family members where possible.</AbstractText>Median age at AF onset was 46.0 years [interquartile range 33.0-54.0], and 35.6% had a family history of AF. Overall, 63 very rare AAC variants were identified in 60 of 303 lone AF probands, and 10 of 19 (52.6%) had evidence of co-segregation with AF. Among the 63 lone AF probands who had 45 genes screened, the very rare variant burden was 22%. Compared with the 4300 EA ESP, the proportion of lone AF probands with a very rare AAC variant in CASQ2 and NKX2-5 was increased 3-5-fold (P <.05).</AbstractText>No very rare AAC variants were identified in ~80% of lone AF probands. Potential reasons for the lack of very rare AAC variants include a complex pattern of inheritance, variants in as yet unidentified AF genes or in noncoding regions, and environmental factors.</AbstractText>© 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.</CopyrightInformation> |
12,553 | Every patient with atrial fibrillation has his (her) own optimal heart rate. | Heart rate control is an important part of atrial fibrillation (AF) treatment and the recommendation for the target rate has become lenient in the recent guideline. Since heart rhythm of AF patients is irregularly irregular with great rate variation, the number of effective ventricular contractions may be different within a given time period among patients with similar heart rates and it may further lead to different levels of cardiac output. Therefore, we propose that every AF patient has his (her) own optimal heart rate, or to say that, the target for rate control in each AF patient should be individualized. This optimal heart rate can be defined by pulse counting, echocardiography or cardiopulmonary exercise test. With this new target, patients will achieve higher cardiac output with better exercise tolerance and life quality, even an improved prognosis. |
12,554 | Learning electrocardiogram on YouTube: how useful is it? | YouTube has become a useful resource for knowledge and is widely used by medical students as an e-learning source. The purpose of this study was to assess the videos relating electrocardiogram (ECG) on YouTube.</AbstractText>YouTube was searched on May 28, 2013 for the search terms "AF ecg" for atrial fibrillation, "AVNRT" for atrioventricular nodal reentrant tachycardia, "AVRT" for atrioventricular reentrant tachycardia, "AV block or heart block" for atrioventricular block, "LBBB, RBBB" for bundle branch block, "left anterior fascicular block or left posterior fascicular block" for fascicular blocks, "VT ecg" for ventricular tachycardia, "long QT" and "Brugada ecg". Non-English language, unrelated and non-educational videos were excluded. Remaining videos were assessed for usefulness, source and characteristics. Usefulness was assessed with using a checklist developed by the authors.</AbstractText>One hundred nineteen videos were included in the analysis. Sources of the videos were as follows: individuals n=70, 58.8%, universities/hospitals n=10, 8.4% and medical organizations n=3, 2.5%, health ads n=10 8.4%, health websites n=26, 21.8%. Fifty-six (47.1%) videos were classified as very useful and 16 (13.4%) videos were misleading. 90% of the videos uploaded by universities/hospitals were grouped as very useful videos, the same ratio was 45% for the individual uploads. There were statistically significant differences in ECG diagnosis among the groups (for very useful, useful and misleading, p<0.001, 0.02 and 0.008, respectively). The ratio of the misleading information in ventricular tachycardia videos was found to be 42.9%.</AbstractText>YouTube has a substantial amount of videos on ECG with a wide diversity from useful to misleading content. The lack of quality content relating to ECG on YouTube necessitates that videos should be selected with utmost care.</AbstractText>© 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,555 | Brain natriuretic peptide in acute ischemic stroke. | Elevated serum brain natriuretic peptide (BNP) levels are associated with cardioembolic stroke mainly because of atrial fibrillation (AF). However, the mechanisms of increased serum BNP levels are hitherto unclear. We aimed to identify the factors associated with increased BNP levels in patients with acute ischemic stroke. We measured serum BNP levels in consecutive patients aged 18 years or older. Stroke subtypes were classified using the Trial of ORG 10172 in Acute Stroke Treatment criteria. Categorical variables included age, sex, smoking status, alcohol consumption status, hypertension, diabetes mellitus, dyslipidemia, coronary artery disease (CAD), AF, antiplatelet therapy, and anticoagulant therapy. Continuous variables included hemoglobin, creatinine (Cr), β-thromboglobulin, platelet factor 4, thrombin-antithrombin complex, and d-dimer levels. We further determined the relationship between serum BNP and intima-media thickness, left ventricular ejection fraction, size of infarction, National Institutes of Health Stroke Scale score on admission, and modified Rankin Scale (mRS) score at discharge. Of the 231 patients (mean age, 71 ± 12 years) with acute ischemic stroke (AIS), 36% were women. Serum BNP levels significantly correlated with CAD, AF, Cr, mRS, and cardioembolism (CE) (Dunnett method, P = .004). BNP levels were significantly higher in patients with larger infarcts, higher mRS scores, and higher CHADS2 scores. The levels were higher in patients with larger infarcts, higher mRS scores at discharge, and higher CHADS2 scores among AF patients. |
12,556 | Poor prognosis of rare sarcomeric gene variants in patients with dilated cardiomyopathy. | In dilated cardiomyopathy (DCM), the clinical and prognostic implications of rare variants in sarcomeric genes remain poorly understood. To address this question, we analyzed the outcome of rare sarcomeric gene variants in patients enrolled in our Familial Cardiomyopathy Registry.</AbstractText>DCM families harboring rare sarcomeric variants in MYH6, MYH7, MYBPC3, TNNT2, and TTN were identified. Genotype-phenotype association analysis was performed, and long-term survival-free from death or heart transplant was compared between carriers and noncarriers.</AbstractText>We found 24 rare variants (3 in MYH6, 3 in MYH7, 3 in MYBPC3, 2 in TNNT2, and 13 in TTN) affecting 52 subjects in 25 families. The phenotypes of variant carriers were severe (3 sudden deaths, 6 heart failure deaths, 8 heart transplants, 2 ventricular fibrillations). There was no difference in the overall long-term survival between carriers and the 33 noncarriers (p = 0.322). However after 50 years of age, the combined endpoint of death or transplant was decreased in carriers as compared to noncarriers (p = 0.026).</AbstractText>Patients with DCM carrying rare variants in sarcomeric genes manifest a poorer prognosis as compared to noncarriers after the age of 50 years. These data further support the role of genetic testing in DCM for risk stratification.</AbstractText>© 2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,557 | Early repolarization syndrome: electrocardiographic signs and clinical implications. | Early repolarization syndrome (ERS) was previously considered as a benign variant, but it has recently emerged as a risk marker for idiopathic ventricular fibrillation (VF) and sudden death. As measured by electrocardiogram (ECG), early repolarization is characterized by an elevation of the J point and/or ST segment from the baseline by at least 0.1 mV in at least two adjoining leads. In particular, early repolarization detected by inferior ECG leads was found to be associated with idiopathic VF and has been termed as ERS. This condition is mainly observed in young men, athletes, and blacks. Also, it has become evident that electrocardiographic territory, degree of J-point elevation, and ST-segment morphology are associated with different levels of risk for subsequent ventricular arrhythmia. However, it is unclear whether J waves are more strongly associated with a depolarization abnormality rather than a repolarization abnormality. Several clinical entities can cause ST-segment elevation. Therefore, clinical and ECG data are essential for differential diagnosis. At present, the data set is insufficient to allow risk stratification in asymptomatic individuals. ERS, idiopathic VF, and Brugada syndrome (known as J-wave syndromes) are three clinical conditions that share many common ECG features; however, their clinical consequences are remarkably different. This review summarizes the current electrocardiographic data concerning ERS with clinical implications. |
12,558 | Atrial flutter or fibrillation is the most frequent and life-threatening arrhythmia in myotonic dystrophy. | Several arrhythmias were reported in myotonic dystrophy (MD).</AbstractText>To evaluate the prevalence of atrial fibrillation (AF) and atrial flutter (AFL) in MD and the clinical consequences.</AbstractText>One hundred sixty-one patients, mean age 41 ± 14 years, were referred for a type 1 MD. All patients were asymptomatic except four patients and followed during 5 ± 4 years. Electrocardiogram (ECG), echocardiography assessing left ventricular ejection fraction, and Holter monitoring were obtained and repeated.</AbstractText>Twenty-seven patients (17%) presented sustained (>1 hour) AF (n = 15) or AFL (n = 12); two of them presented syncope-related 1/1 AFL. In one of them, 16 years of age, cardiac defibrillator was implanted for a diagnosis of ventricular tachycardia, but the true diagnosis was established after inappropriate shocks. AFL ablation was performed in five patients, but four developed AF. The other seven patients with AFL developed AF. During the follow-up, 22 patients died (14%) from cardiac and respiratory failure; eight patients with AF/AFL died (30%) while only 14 without AF/AFL died (10%; P < 0.01). Univariate analysis indicated that age >40 years (death: 48 ± 14 vs 40 ± 8 in alive patients), abnormal ECG, and occurrence of AF/AFL were significant factors of death. At multivariate analysis, AF at ECG (odds ratio: 3.12) and age >40 (odds ratio: 3.14) were the sole independent variables predicting death.</AbstractText>AF and AFL were frequent in MD and increased mortality. AFL could present as 1/1 AFL with a poor tolerance and a risk of misdiagnosis despite frequent conduction disturbances. This arrhythmia could explain wide QRS tachycardia occurring in MD and interpreted as VT.</AbstractText>©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,559 | Increase in prominence of electrocardiographic J waves after a single dose of propofol in a patient with early ventricular repolarisation. | J waves appear on an electrocardiogram as an elevation of the J point in the terminal portion of the QRS complex. J waves are often benign, but may be associated with malignant ventricular arrhythmias. In some cases, such problems appear to have been precipitated by propofol infusions. We observed a sudden increase in J waves and profound hypotension following a single intravenous dose of propofol in an 84-year-old woman with early repolarisation in the inferior ventricular wall. When early repolarisation (as shown by electrocardiographic J waves) is observed in the inferior ventricular wall pre-operatively, patients should be carefully monitored. Myocardial ischaemia and the use of drugs that might worsen J waves should be avoided. |
12,560 | Arrhythmogenesis after acute myocardial necrosis with and without preceding ischemia in rats. | The relative role of acute myocardial ischemia and infarction in ventricular arrhythmogenesis is incompletely understood. We compared the arrhythmia pattern after ischemia/infarction to that observed after direct myocardial necrosis without preceding ischemia in rats.</AbstractText>Coagulation necrosis was induced in Wistar rats (n=20, 280±3 g) by radiofrequency current application (for 15 s) from a 4-mm-tip ablation catheter. Myocardial infarction was induced by coronary artery ligation with (n=10) or without (n=10) reperfusion. Using 24-h telemetry recording, we examined ventricular arrhythmias, voluntary motor activity and indices of sympathetic activation.</AbstractText>The coagulation-necrosis volume was 24.4%±0.6%, comparable to the infarct size in the absence of reperfusion. Acute left ventricular failure and sympathetic activation were similar in the three groups. Coagulation necrosis induced ventricular fibrillation immediately, followed by a second peak after ∼1 h. Reperfusion decreased ventricular arrhythmias, whereas a second arrhythmogenic period (between the third and the eight hour) was noted in non-reperfused infarcts (mainly monomorphic ventricular tachycardia).</AbstractText>Distinct arrhythmia patterns occur after myocardial infarction (with or without reperfusion) and after direct necrosis. They are not produced by differences in sympathetic activation and are likely related to the evolution of myocardial injury. The necrosis rat model may be useful in studies of arrhythmogenesis.</AbstractText> |
12,561 | Effect of defibrillation threshold testing-induced ventricular fibrillation on renal function. | The effect of defibrillation threshold (DFT) testing with induction of ventricular fibrillation (VF) on renal function is currently unknown. This study examined the acute effect of DFT testing on renal function in patients undergoing implantable cardioverter defibrillator (ICD) implantation.</AbstractText>We performed a prospective cohort study of 148 consecutive patients who underwent ICD implantation from January 1, 2007 to May 30, 2008. Patients were assigned to one of two cohorts: a DFT group who underwent DFT testing at device implantation and a no-DFT group that was not tested. Baseline and 24-h postprocedure renal function were assessed with measurements of serum creatinine and estimated glomerular filtration rate (GFR) by the Modified Diet in Renal Disease equation. Changes in serum creatinine and estimated GFR were compared between cohorts. Ninety-eight patients (66%) underwent DFT testing (average VF induction count, 1.5 ± 0.9; mean VF duration, 10 ± 4 s). Fifty patients (34%) were not tested. Patients in the no-DFT group had lower mean left ventricular ejection fraction, higher New York Heart Association class, higher atrial fibrillation incidence, and greater intravenous contrast utilization at device implant. Baseline and postprocedure serum creatinine values were similar between groups (baseline, 1.25 ± 0.45 mg/dL; post-ICD, 1.26 ± 0.5 mg/dL). Baseline GFR was lower in the DFT cohort (55.2 ± 18.8 mL/min/BSA vs 63.7 ± 22.7 mL/min/BSA, p = 0.023). No significant differences between groups were observed in the mean change in serum creatinine or estimated GFR.</AbstractText>DFT testing at the time of ICD implantation is not associated with acute adverse effects on renal function.</AbstractText> |
12,562 | Suppression of ventricular fibrillation by electrical modification of the Purkinje system in hypertrophic cardiomyopathy. | A 56-year-old man in hypertrophic cardiomyopathy had an electrical storm caused by ventricular fibrillation (VF). Mapping during the initiation of the VF triggered by a premature ventricular contraction (PVC1), with right bundle branch block (RBBB)-like morphology and superior axis, demonstrated a prominent Purkinje-muscle junction (PMJ) delay at the distal portion of the left posterior fascicle. Delivery of radiofrequency (RF) energy to this area abolished the VF triggered by the PVC1. However, VF emerged by triggering another PVC (PVC2) with RBBB-like morphology and inferior axis. Similarly, the initiation of VF was associated with the PMJ delay at the peripheral left anterior fascicle, where RF delivery completely suppressed the VF. The PMJ delay and subsequent Purkinje-muscle reentry-like activity could be essential for the initiation of the Purkinje-related VF. |
12,563 | Programming implantable cardioverter-defibrillators in patients with primary prevention indication to prolong time to first shock: results from the PROVIDE study. | Shock therapy delivery by implantable cardioverter-defibrillators (ICD) can be painful and may have adverse consequences. Reducing shock burden for patients with ICDs would be beneficial.</AbstractText>PROVIDE was a prospective, randomized study of primary prevention ICD patients. Patients in the experimental group received a combination of programmed parameters with higher detection rates, longer detection intervals, empiric antitachycardia pacing (ATP), and optimized supraventricular tachycardia (SVT) discriminators, while those in the control group were programmed with conventional parameters. Shock therapy and arrhythmic syncope were compared.</AbstractText>Of 1,670 patients enrolled (846 in the experimental group, 824 in the control group) and monitored over a follow-up of 530 ± 241 days, 202 patients received shock therapy for any cause (82 in the experimental group and 120 in the control group). The median time to first shock was significantly prolonged (13.1 vs 7.8 months, hazard ratio [HR]: 0.62, 95% confidence interval [CI]: 0.47 to 0.82, P = 0.0005) and the 2-year shock rate significantly reduced (12.4% vs 19.4%, P < 0.001) in the experimental group compared to the control group. There was no increase in arrhythmic syncope (HR: 1.64, 95% CI: 0.69 to 3.90, P = 0.26), while the overall mortality was reduced (HR: 0.7, 95% CI: 0.50 to 0.98, P = 0.036) in the experimental group compared to the control group.</AbstractText>A combination of programmed parameters utilizing higher detection rate, longer detection intervals, empiric ATP, and optimized SVT discriminators reduced ICD therapies without increasing arrhythmic syncope and was associated with reduction in all-cause mortality among ICD patients.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
12,564 | Prevalence and risk factors for cardiac diseases in a hospital-based population of 3,434 horses (1994-2011). | Risk factors for cardiac diseases in horses have not been explored in a large population of animals.</AbstractText>To describe risk factors for various cardiac diseases in a hospital-based population of horses.</AbstractText>Files of 3,434 horses admitted at the Internal Medicine Department of the Liege Equine Teaching Hospital between 1994 and 2011 were reviewed and of those, 284 were categorized as having moderate-to-severe cardiac disease.</AbstractText>Observational study. After calculating prevalence for each cardiac disease, we tested whether breed (chi-square test) or sex, age, body weight (BW), and other cardiac diseases (logistic regressions) were risk factors (p < .05 significant).</AbstractText>Mitral regurgitation (MR, 4.4%), atrial fibrillation (AF, 2.3%), aortic regurgitation (AR, 2.1%), and tricuspid regurgitation (TR, 1.7%) were the most common cardiac abnormalities detected. Determinants were male sex and increasing age for AR (OR = 2.03, CI = 1.07-4.94), racehorses breed and middle-age for TR (OR = 4.36; CI = 1.10-17.24), and high BW for AF (OR = 3.54; CI = 1.67-7.49). MR was the most common valvular disease associated with AF, clinically important ventricular arrhythmia, pulmonary regurgitation (PR), and congestive heart failure (CHF). TR was also associated with AF, PR, and CHF; AR was not associated with CHF.</AbstractText>Several previously suspected risk factors for a variety of equine cardiac diseases are statistically confirmed and other risk factors are highlighted in the studied hospital-based population. These observations should be taken into account in health and sport's monitoring of horses presenting predisposing factors.</AbstractText>Copyright © 2013 by the American College of Veterinary Internal Medicine.</CopyrightInformation> |
12,565 | Predictive value of atrial high-rate episodes for arterial stiffness and endothelial dysfunction in dual-chamber pacemaker patients. | Various pacing studies have demonstrated an association between right ventricular pacing (RVp) and atrial fibrillation (AF), even after preserving atrioventricular (AV) synchrony. We aimed to assess the interaction between arterial stiffness, endothelial function and atrial high-rate episodes (AHRE) in patients with dual-chamber pacemakers.</AbstractText>We studied 101 patients with dual-chamber pacemakers incorporated with sophisticated AF detection and therapy algorithms. Macrovascular endothelial dysfunction (ED) was measured by the relative change in aortic augmentation index (AIx), using carotid artery applanation tonometry in response to inhaled salbutamol and sublingual glyceryl trinitrate. Microvascular ED was measured by cutaneous laser Doppler flowmetry (LDF) in response to acetylcholine (Ach, endothelium dependent) and sodium nitroprusside (SNP, endothelium independent). Arterial stiffness was measured using carotid-femoral pulse wave velocity (PWVcf). 'Reservoir pressure' (Pr, MATLAB) describes the aortic 'cushioning' properties.</AbstractText>Mean age of the cohort was 72.1 ± 10.8 years; men (n = 69) 68.3%. Of 101 dual-chamber pacemaker patients, 23.8% (n = 24) had AHRE detected on the baseline pacemaker interrogation. PP, PWVcf and Pr were significantly higher in patients with AHRE compared with those without AHRE. The change in AIx with salbutamol (∆% AIx Sal) and acetylcholine-induced changes in LDF (Δ%LDF Ach) were lower in patients with AHRE compared with those without AHRE. In patients with AHRE, significant correlations were observed between%Vp and Δ%LDF Ach (P = 0.03) as well as between PP and Δ%LDF Ach (P = 0.05). On multivariate analysis, PP, Pr, PWVcf and ∆% AIx Sal remained as independent predictors of AHRE.</AbstractText>In patients with dual-chamber pacemakers, both higher arterial stiffness and greater endothelial dysfunction independently predicted AHRE, irrespective of the degree (or mode) of pacing. Arterial stiffness and endothelial dysfunction may potentially contribute to the perpetuation of atrial arrhythmias beyond the adverse effects of ventricular pacing alone.</AbstractText>© 2013 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.</CopyrightInformation> |
12,566 | Novel heuristic search for ventricular arrhythmia detection using normalized cut clustering. | Processing of the long-term ECG Holter recordings for accurate arrhythmia detection is a problem that has been addressed in several approaches. However, there is not an outright method for heartbeat classification able to handle problems such as the large amount of data and highly unbalanced classes. This work introduces a heuristic-search-based clustering to discriminate among ventricular cardiac arrhythmias in Holter recordings. The proposed method is posed under the normalized cut criterion, which iteratively seeks for the nodes to be grouped into the same cluster. Searching procedure is carried out in accordance to the introduced maximum similarity value. Since our approach is unsupervised, a procedure for setting the initial algorithm parameters is proposed by fixing the initial nodes using a kernel density estimator. Results are obtained from MIT/BIH arrhythmia database providing heartbeat labelling. As a result, proposed heuristic-search-based clustering shows an adequate performance, even in the presence of strong unbalanced classes. |
12,567 | Simulation study of complex action potential conduction in atrioventricular node. | The atrioventricular (AV) node, which is located between the atria and ventricles of the heart, acts as important roles in cardiac excitation conduction between the two chambers. Although there are multiple conduction pathways in the AV node, the structure of the AV node has not been clarified. In this study, we constructed a one-dimensional model of the AV node and simulated excitation conduction between the right atrium and the bundle of His via the AV node. We also investigated several characteristics of the AV node: (1) responses of the AV node to high-rate excitation in the right atrium, (2) the AV nodal reentrant beat induced by premature stimulus, and (3) ventricular rate control during atrial fibrillation with various methods. Our simulation results suggest that multiple conduction pathways act as important roles in controlling the ventricular rate. The one-dimensional model constructed in this study may be useful to analyze complex conduction patterns in the AV node. |
12,568 | Blind source separation in characterizing ECG pre-shock waveforms during Ventricular Fibrillation. | Ventricular Fibrillation (VF) is a cardiac arrhythmia for which the only available treatment option is defibrillation by electrical shock. Existing literature indicates that VF could be the manifestation of different sources controlling the heart with different degrees of organization. In this work we test the hypothesis that the pre-shock waveforms of successful and unsuccessful shock outcomes could be related to the number of independent sources present in these waveforms. The proposed method uses Blind Source Separation (BSS) to extract independent components in frequency direction from a pig database consisting of 20 pre-shock waveforms. The slope of the energy capture curve was used as an indicator to demonstrate the number of independent sources required to model the pre-shock waveforms. The results were also quantified by performing a linear discriminant analysis based classification achieving an overall classification accuracy of 75%. The results indicate that successful cases can be modeled with less number of independent sources compared to unsuccessful cases. |
12,569 | Effect of premature activation in analyzing QT dynamics instability using QT-RR model for ventricular fibrillation and healthy subjects. | Perturbations in the normal heart rate are generally represented by the presence of premature activation (PA) beats in the surface electrocardiogram (ECG). The presence of PA is one of the main reasons of instability in QT dynamics which could initiate arrhythmia. Analyzing Boundary-Input Boundary-Output (BIBO) stability of the short term linear autoregressive QT-RR model is a way of detecting instability in QT dynamics from the ECG. The aim of this paper is to investigate if PA is the only reason for instability in the ventricular repolarisation process, which is denoted by QT interval of surface ECG. Ten healthy subjects with normal sinus rhythm and seven patients with sustained ventricular tachycardia (VT) were analyzed in this study. 10 min long ECG data were collected from each subject of the healthy group and 10 min ECG before the start of VT were taken for each subject of the VT group. Autoregressive QT-RR model was derived for each non-overlapping 1 min long ECG segment of the 10 min long ECG data. Instability in QT dynamics was quantified by measuring the numbers of unstable segments in ECG data for each subject ( ). Results of this study revealed that like the VT group subjects, QT instability detected by QT-RR model is also found in healthy subjects whose ECG segments are mostly free from PA beats. This finding indicates that BIBO unstable QT characteristics might arise from other inherent factors of cardiovascular system in addition to PA. |
12,570 | Chaotic phase space differential algorithm for real-time detection of ventricular arrhythmias: application in animal model. | Life-threatening ventricular arrhythmias remain the main cause of death among patients with cardiovascular diseases. Efforts have been spent on early detection of such fatal cardiac signs. We have previously reported a novel chaotic phase space differential (CPSD) algorithm in discriminating VPC, VT, and VF from normal sinus rhythm with both good sensitivity and specificity. In this article, we apply this algorithm on the rat model of calcium induced ventricular tachycardia. Peaked CPSD values can be observed along with the occurrence of ventricular tachycardia. In addition, minor ECG changes such as new onset S wave or sinus arrhythmia can also be noted on CPSD tracing. We believe that the CPSD algorithm not only is capable of detecting lethal ventricular arrhythmias, but also is potentially a good tool for long-term monitoring the change of ECG signals. |
12,571 | Models of ventricular arrhythmia mechanisms. | The mechanisms that initiate and sustain ventricular arrhythmias in the human heart are clinically important, but hard to study experimentally. In this study, a monodomain model of electrical activation was used to examine how dynamics of electrophysiology at the cell scale influence the surface activation patterns of VF at the tissue scale. Cellular electrophysiology was described with two variants of a phenomenological model of the human ventricular epicardial action potential. The tissue geometry was an 8.0 × 8.0 × 1.2 cm 3D tissue slab with axially symmetric anisotropy. In both cases an initial re-entrant wave fragmented into multiple wavelets of activation. The model variant with steep action potential duration restitution produced much more complex activation, with a greater average number of filaments (13.79) than the variant with less steep restitution (3.08). More complex activation was associated with proportionally fewer transmural filaments, and so the average number of epicardial wavefronts and phase singularities per filament was lower. The average number of epicardial phase singularities and wavefronts for the model variant with less steep restitution were consistent with experimental observations in the human heart. This study shows that small changes in cell scale dynamics can have a large influence on the complexity of re-entrant activation in simulated 3D tissue, as well as on the features observed on the epicardial surface. |
12,572 | Automated signal pattern detection in ECG during human ventricular arrhythmias. | Ventricular arrhythmias seriously affects cardiac function. Of these arrhythmias, Ventricular fibrillation is considered as a lethal cardiac condition. Recent studies have reported that ventricular arrhythmias are not completely random and may exhibit regional spatio-temporal organizations. These organizations could be indicative of reoccurring signal patterns and might be embedded within the surface electrocardiograms (ECGs) during ventricular arrhythmias. In this work, we aim to identify such reoccurring ECG signal patterns during ventricular arrhythmias. The detection of such signal patterns and their distribution could be of help in sub-classifying the affected population for better targeted diagnosis and treatment. Our analysis on 14 ECG segments (on average 3.24 minutes per segment) obtained from the MIT-BIH ventricular arrhythmia database identified three reoccurring signal patterns. A wavelet based technique was developed for automating the pattern identification process using ECGs. The proposed method achieved automated detection accuracies of 73.3%, 75.0% and 86.6% for the proposed signal patterns. |
12,573 | Cardiac resynchronization therapy in acute pulmonary edema: A case report. | We are reporting a case of 71-year old lady with a dual chamber demand pacemaker, who developed acute pulmonary edema due to an acute left ventricular (LV) dysfunction and worsening in mitral valve regurgitation after atrioventricular nodal ablation for uncontrolled atrial fibrillation. This was attributed to right ventricular apical pacing leading to LV dyssynchronization. Patient dramatically improved within 12-24 h after upgrading her single chamber pacemaker to biventricular pacing. Our case demonstrates that biventricular pacing can be an effective modality of treatment of acute congestive heart failure. In particular, it can be used when it is secondary to LV dysfunction and severe mitral regurgitation attributed to significant dyssynchrony created by right ventricular pacing in patients with atrioventricular nodal ablation for chronic atrial fibrillation. |
12,574 | Subcutaneous implantable defibrillator: State-of-the art 2013. | The subcutaneous implantable cardioverter-defibrillator (S-ICD) has recently been approved for commercial use in Europe, New Zealand and the United States. It is comprised of a pulse generator, placed subcutaneously in a left lateral position, and a parasternal subcutaneous lead-electrode with two sensing electrodes separated by a shocking coil. Being an entirely subcutaneous system it avoids important periprocedural and long-term complications associated with transvenous implantable cardioverter-defibrillator (TV-ICD) systems as well as the need for fluoroscopy during implant surgery. Suitable candidates include pediatric patients with congenital heart disease that limits intracavitary lead placements, those with obstructed venous access, chronic indwelling catheters or high infection risk, as well as young patients with electrical heart disease (e.g., Brugada Syndrome, long QT syndrome, and hypertrophic cardiomyopathy). Nevertheless, given the absence of intracavitary leads, the S-ICD is unable to offer pacing (apart from short-term post-shock pacing). It is therefore not suitable in patients with an indication for antibradycardia pacing or cardiac resynchronization therapy, or with a history of repetitive monomorphic ventricular tachycardia that would benefit from antitachycardia pacing. Current data from initial clinical studies and post-commercialization "real-life" case series, including over 700 patients, have so far been promising and shown that the S-ICD successfully converts induced and spontaneous ventricular tachycardia/ventricular fibrillation episodes with associated complication and inappropriate shock rates similar to that of TV-ICDs. Furthermore, by using far-field electrograms better tachyarrhythmia discrimination when compared to TV-ICDs has been reported. Future results from ongoing clinical studies will determine the S-ICD system's long-term performance, and better define suitable patient profiles. |
12,575 | Hyperacute drug-induced hepatitis with intravenous amiodarone: case report and review of the literature. | Amiodarone is a benzofuran class III antiarrhythmic drug used to treat a wide spectrum of ventricular tachyarrhythmias. The parenteral formulation is prepared in polysorbate 80 diluent. We report an unusual case of acute elevation of aminotransaminase concentrations after the initiation of intravenous amiodarone. An 88-year-old Caucasian female developed acute hepatitis and renal failure after initiating intravenous amiodarone for atrial fibrillation with a rapid ventricular response in the setting of acutely decompensated heart failure and hepatic congestion. Liver transaminases returned to baseline within 7 days after discontinuing the drug. Researchers hypothesized that this type of injury is related to liver ischemia with possible superimposed direct drug toxicity. The CIOMS/RUCAM scale identifies our patient's acute hepatitis as a highly probable adverse drug reaction. Future research is needed to understand the mechanisms by which hyperacute drug toxicity occurs in the setting of impaired hepatic perfusion and venous congestion. |
12,576 | Safety and efficacy of strategic implantable cardioverter-defibrillator programming to reduce the shock delivery burden in a primary prevention patient population. | Strategically chosen ventricular tachycardia (VT)/ventricular fibrillation (VF) detection and therapy parameters aimed at reducing shock deliveries were proven effective in studies that utilized single manufacturer devices with a follow-up of up to 1 year. Whether these beneficiary effects can be generalized to additional manufacturers and be maintained for longer periods is to be determined. Our aim was to evaluate the durability and applicability of the programming of strategic implantable cardioverter-defibrillators (ICDs) of various manufacturers, which is aimed at reducing the shock delivery burden in primary prevention ICD recipients.</AbstractText>A retrospective analysis of prospectively collected data of 300 ICD recipients of various manufacturers was conducted; 160 devices were strategically programmed to reduce shocks and 140 were not. The primary endpoint was the composite of death and appropriate shocks. Additional outcomes were inappropriate shocks, syncope events, and non-sustained VTs. At a median follow-up of 24 months, 19 patients died, 31 received appropriate shocks, and 41 received inappropriate shocks. Multivariate analysis showed that strategic programming dedicated to shock reduction was associated with a 64% risk reduction in the primary endpoint [hazard ratio (HR): 0.13-0.93; P = 0.03] and a 70% reduction in inappropriate shock deliveries (HR: 0.16-0.72; P = 0.01). Very few syncope events occurred (five patients, 1.6%), and there was no between-group difference in this outcome.</AbstractText>Utilization of strategically chosen VT/VF detection and therapy parameters was found to be effective and safe in ICDs of various manufacturers at a median follow-up period of 2 years among primary prevention patients.</AbstractText> |
12,577 | Pulmonary vein isolation in patients with Brugada syndrome and atrial fibrillation: a 2-year follow-up. | Pharmacological treatment of atrial fibrillation (AF) in the setting of Brugada syndrome (BS) might be challenging as many antiarrhythmic drugs (AADs) with sodium channel blocking properties might expose the patients to the development of ventricular arrhythmias. Moreover, patients with BS and implantable cardioverter-defibrillator (ICD) might experience inappropriate shocks because of AF with rapid ventricular response. The role of pulmonary vein isolation (PVI) in patients with BS and recurrent episodes of AF has not been established yet. In this study, we analysed the outcome of PVI using radiofrequency energy or cryoballoon (CB) ablation at 2 years follow-up.</AbstractText>Consecutive patients with BS having undergone PVI for drug-resistant paroxysmal AF were eligible for this study. Nine patients (three males; mean age: 52 ± 26 years) were included. Six patients (67%) had an ICD implanted of whom three had inappropriate shocks because of rapid AF. At a mean 22.1 ± 6.4 months follow-up, six patients (67%) were free of AF without AADs. None of the three patients who had experienced inappropriate ICD interventions for AF had further ICD shocks after ablation.</AbstractText>In our study PVI can be an effective and safe procedure to treat patients with BS and recurrent episodes of paroxysmal AF.</AbstractText> |
12,578 | An observational study of extracorporeal CPR for in-hospital cardiac arrest secondary to myocardial infarction. | To determine the effects of extracorporeal cardiopulmonary resuscitation (ECPR) in patients with in-hospital cardiac arrest (IHCA) due to acute myocardial infarction (AMI).</AbstractText>IHCA patients due to AMI undergoing CPR between 1 January 2006 and 1 July 2010 were analysed retrospectively. We compared the survival outcome of 43 patients who received ECPR with that of 23 patients who underwent conventional CPR.</AbstractText>The survival rate was 34.9% for patients who received ECPR and 21.8% for those who received conventional CPR (p=0.4). Increased survival rates to hospital discharge were seen in patients with ST segment elevation (p<0.01), or had initial rhythm of ventricular tachycardia/ventricular fibrillation (VT/VF) during resuscitation (p=0.031).</AbstractText>ECPR may improve survival in cardiac arrest patients who have a ST segment elevation or initial rhythm of VT/VF myocardial infarction.</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> |
12,579 | Gender-related safety and efficacy of cardiac resynchronization therapy. | Cardiac resynchronization therapy (CRT) is an established therapy for patients with chronic heart failure (CHF) and a broad QRS complex. Gender-related safety and efficacy data are necessary for informed patient decision-making for female patients with CHF. The aim of the study was to assess the effects of gender on the outcome of CRT in highly symptomatic heart failure patients.</AbstractText>Gender may have an effect on the outcome of heart failure patients undergoing cardiac resynchronisation therapy.</AbstractText>The study analyzed the 2-year follow-up of 393 New York Heart Association (NYHA) class III/IV patients with a class I CRT indication enrolled in the Management of Atrial Fibrillation Suppression in AF-HF Comorbidity Therapy (MASCOT) study.</AbstractText>In female patients (n = 82), compared with male patients (n = 311), CHF was more often due to dilated cardiomyopathy (74% vs 44%, respectively; P < 0.0001). Females also had a more impaired quality-of-life score and a smaller left ventricular end-diastolic diameter (LVEDD). Women were less likely than men to have received a CRT defibrillator (35% vs 61%, respectively; P < 0.0001). After 2 years, the devices had delivered more biventricular pacing in women than in men (96% ± 13% vs 94% ± 13%, respectively; P < 0.0004). Women had a greater reduction in LVEDD than did men (-8.2 mm ± 11.1 mm vs -1.1 mm ± 22.1 mm, respectively; P < 0.02). Both genders improved similarly in NYHA functional class. Women reported greater improvement than men in quality-of-life score (-21.1 ± 26.5 vs -16.2 ± 22.1, respectively; P < 0.0001). After adjustment for cardiovascular history, women had lower all-cause mortality (P = 0.0007), less cardiac death (P = 0.04), and fewer hospitalizations for worsening heart failure (P = 0.01).</AbstractText>Females exhibited a better response to CRT than did males. Because females have such impressive benefits from CRT, improved screening and advocacy for CRT implantation in women should be considered.</AbstractText>© 2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,580 | Heart failure in patients with atrial fibrillation is associated with a high symptom and hospitalization burden: the RealiseAF survey. | Atrial fibrillation (AF) and heart failure (HF) often coexist; the consequences of such coexistence are unclear.</AbstractText>HF in patients with AF is associated with poor outcomes.</AbstractText>This post hoc analysis of RealiseAF, a survey of AF patients, compared symptoms, hospitalizations, management, and AF control in patients with vs without HF. A total of 10,523 AF patients were analyzed according to presence/absence of HF.</AbstractText>History of HF was present in 45.8%, and in more patients with permanent vs persistent, paroxysmal, or first-episode AF (55.6%, 44.3%, 32.9%, and 29.8%, respectively; P < 0.0001). Patients with vs those without history of HF, and patients with HF and reduced ejection fraction (HF-REF) vs those with HF and a preserved ejection fraction (HF-PEF), had more frequent cardiovascular (CV) risk factors and more severe symptoms. Presence vs absence of HF, and HF-REF vs HF-PEF, were associated with lower rates of AF control (54.6% vs 62.8% and 49.3% vs 60.3%, respectively; both P < 0.0001). The rate-control strategy was used more frequently in HF patients, particularly those with HF-REF, than the rhythm-control strategy. CV hospitalizations occurred more frequently in patients with HF than those without (41.8% vs 17.5%; P < 0.001) and more frequently in patients with HF-REF than in those with HF-PEF (51.6% vs 35.6%; P < 0.0001).</AbstractText>AF patients with HF, particularly HF-REF, experience heavy symptom and hospitalization burdens, and have relatively low rates of AF control. Further studies are needed to identify ways to improve the management and treatment outcomes of this very high-risk patient population.</AbstractText>© 2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,581 | [Monomorphic ventricular tachycardia during the ajmaline test]. | A 44-year-old male patient admitted with palpitations was diagnosed with tachycardia with wide QRS, but recovered after being treated with amiodarone. The patient's coronary angiography was normal. As the patient's resting ECG was compatible with Brugada type 2, an ajmaline challenge test was scheduled. The infusion procedure was suspended following an observation of type 1 ECG findings in the 4th minute of infusion. Approximately 10-15 seconds later, a monomorphic ventricular tachycardia with a rate of 150 beats/minute developed. In the follow-up, the patient's heartbeat returned spontaneously to the sinus rhythm within 3-4 minutes. Polymorphic ventricular tachycardia or ventricular fibrillation tachyarrhythmias usually result in syncope or sudden cardiac death in cases of Brugada syndrome, while monomorphic tachycardia, as in our case, is rare. Here, we present a rare case of monomorphic ventricular tachycardia, which was observed during the ajmaline challenge test. |
12,582 | Perioperative conduction disturbances after transcatheter aortic valve replacement. | Cardiac conduction disturbances after transcatheter aortic valve replacement (TAVR) are common and important. The risk factors and outcome effects of atrial fibrillation after TAVR recently have been appreciated. The paucity of clinical trials has resulted in the absence of clinical guidelines for the management of this important arrhythmia in this high-risk patient population. Given this evidence gap and clinical necessity, it is likely that clinical trials in the near future will be designed and implemented to address these issues. Prompt recognition and proper management of atrioventricular block remain essential in the management of patients undergoing TAVR, because heart block of all types is common and may require permanent pacemaker implantation. The current evidence base has described the incidence, risk factors, and current outcomes of this conduction disturbance in detail. As the practice of TAVR evolves and novel valve prostheses are developed, a focus on minimizing damage to the cardiac conductive system remains paramount. It remains to be seen how the next generation of TAVR prostheses will affect the incidence, risk factors, and clinical outcomes of associated conduction disturbances. |
12,583 | Intra-cardiac thrombus resolution after anti-coagulation therapy with dabigatran in a patient with mid-ventricular obstructive hypertrophic cardiomyopathy: a case report. | Although dabigatran, a novel oral anti-coagulant, has been approved for the prevention of thromboembolism in patients with non-valvular atrial fibrillation, the efficacy of dabigatran for the resolution of established intra-cardiac thrombi has not been validated. Herein is describe a case in which dabigatran was effective for thrombus resolution in a patient with a left ventricular aneurysm.</AbstractText>A 59-year-old Japanese man with a mid-ventricular obstructive hypertrophic cardiomyopathy-associated apical aneurysm presented with a left ventricular apical thrombus (15.0mm×17.0mm). Anti-coagulation therapy with dabigatran (150mg b.i.d. with meals) was initiated. Following dabigatran administration, weekly echocardiographic examinations demonstrated gradual decreases in thrombus size. After three weeks, no thrombus was detected and no systemic thromboembolic events had occurred.</AbstractText>The left ventricular apical thrombus resolved after dabigatran administration. Hence, dabigatran may represent an alternative to warfarin as a therapeutic option in patients with previously detected intra-cardiac thrombus.</AbstractText> |
12,584 | Does health-related quality of life predict hospitalization or mortality in patients with atrial fibrillation? | Poor health-related quality of life (QOL) is related to morbidity and mortality in coronary heart disease and ventricular arrhythmias as well as to mortality in patients with heart failure (HF) and atrial fibrillation (AF). This study examined the contributions of QOL to the prediction of 1-year hospitalization and mortality in patients with AF, independent of HF.</AbstractText>This study used the public use dataset from the NHLBI/NIH AFFIRM randomized clinical trial. Patients enrolled in the QOL substudy (N = 693) were randomly assigned to rate or rhythm control. QOL was assessed with the Medical Outcomes Study 36-item Short Form Health Survey (SF-36) and the Quality of Life Index-Cardiac Version (QLI-CV). Data were analyzed with logistic regression to predict 1-year hospitalization and Cox proportional hazards analysis to predict mortality.</AbstractText>In the first year of participation in the study 37% (n = 256) were hospitalized; mortality was 14.3% (n = 93) with mean follow-up of 3.5 years. Patients' mean age was 69.8 ± 8.2 years, were largely male (62%), and white (93%). Patient histories included 70.8% hypertension, 38.2% coronary artery disease (CAD), and 23.7% HF. History of stroke, HF, rhythm control arm, lower SF-36 mental component scores (MCS), and lower SF-36 physical component scores (PCS) predicted hospitalization (P < 0.001). Diabetes, female gender, older age, CAD, hypertension, and lower PCS predicted mortality (P < 0.001).</AbstractText>QOL adds meaningful information beyond traditional biomedical factors to the prediction of mortality and/or hospitalization of patients with AF. Interventions for improving QOL and helping patients adapt to AF treatments may decrease hospitalization and improve survival.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
12,585 | Endocavitary structures in the outflow tract: anatomy and electrophysiology of the conus papillary muscles. | Catheter ablation is an increasingly used and successful treatment choice for right ventricular outflow tract (RVOT) arrhythmias. While the role of endocavitary structures and the regional morphology of the ventricular inflow tract and the right atrium as a cause for difficulty with successful ablation are well described, similar issues within the RVOT are not well understood. It is also not commonly appreciated that one of the papillary muscles is located within the proximal RVOT. We report 3 patients in which ventricular arrhythmia was targeted and ablated in the conus papillary muscle. The anatomic features, potential role of the fascicular conduction system, and unique challenges with mapping arrhythmia arising from this structure are discussed. |
12,586 | Low-tilt monophasic and biphasic waveforms compared with standard biphasic waveforms in the transvenous defibrillation of ventricular fibrillation. | Commercially available implantable defibrillators utilize a high-tilt waveform. Studies in atrial fibrillation and transthoracic defibrillation of ventricular fibrillation (VF) have shown improved defibrillation efficacy using low-tilt (LT) waveforms. We investigated the feasibility, efficacy, and safety of a LT waveform in the transvenous defibrillation of VF and hypothesized that it would be more efficacious than standard tilted biphasic (STB) waveforms.</AbstractText>The investigation was performed in four phases in a porcine model: an efficacy study of LT monophasic waveforms (n = 9), an efficacy study of LT biphasic waveforms (n = 9), a comparison study between the most successful LT waveforms and clinically available STB waveforms (n = 15), and a safety study (n = 9). A total of 1,056 shocks were delivered (phase 1: 288, phase 2: 288, phase 3: 480). The LT biphasic 8/4-ms waveform was significantly more likely to successfully defibrillate than the LT monophasic and STB waveforms with an odds ratio of 122.3 (95% confidence interval: 32.5, 460.2, P < 0.001). The calculated defibrillation threshold (E50) for the LT 8/4-ms waveform was 12.7 J compared to 43.5 J and 45.5 J for STB waveforms 6/6 ms and 8/4 ms, respectively, and 47.7 J for LT 12-ms waveform. The LT 8/4-ms waveform had no lasting detrimental effect on cardiac function, and any transient hemodynamical or biochemical changes observed were comparable to those observed with STB waveforms.</AbstractText>LT waveforms are effective and appear safe in transvenous defibrillation in a porcine model of VF. The LT biphasic 8/4-ms waveform is more efficacious than conventional waveforms.</AbstractText>©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,587 | Characterization of a novel multifunctional resveratrol derivative for the treatment of atrial fibrillation. | Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased risk for stroke, heart failure and cardiovascular-related mortality. Candidate targets for anti-AF drugs include a potassium channel K(v)1.5, and the ionic currents I(KACh) and late I(Na), along with increased oxidative stress and activation of NFAT-mediated gene transcription. As pharmacological management of AF is currently suboptimal, we have designed and characterized a multifunctional small molecule, compound 1 (C1), to target these ion channels and pathways.</AbstractText>We made whole-cell patch-clamp recordings of recombinant ion channels, human atrial I(Kur), rat atrial I(KACh), cellular recordings of contractility and calcium transient measurements in tsA201 cells, human atrial samples and rat myocytes. We also used a model of inducible AF in dogs.</AbstractText>C1 inhibited human peak and late K(v)1.5 currents, frequency-dependently, with IC₅₀ of 0.36 and 0.11 μmol·L(-1) respectively. C1 inhibited I(KACh)(IC₅₀ of 1.9 μmol·L(-1)) and the Na(v)1.5 sodium channel current (IC₅₀s of 3 and 1 μmol·L(-1) for peak and late components respectively). C1 (1 μmol·L(-1)) significantly delayed contractile and calcium dysfunction in rat ventricular myocytes treated with 3 nmol·L(-1) sea anemone toxin (ATX-II). C1 weakly inhibited the hERG channel and maintained antioxidant and NFAT-inhibitory properties comparable to the parent molecule, resveratrol. In a model of inducible AF in conscious dogs, C1 (1 mg·kg(-1)) reduced the average and total AF duration.</AbstractText>C1 behaved as a promising multifunctional small molecule targeting a number of key pathways involved in AF.</AbstractText>© 2013 The British Pharmacological Society.</CopyrightInformation> |
12,588 | Treating resistant hypertension: role of renal denervation. | Arterial hypertension is the most prevalent risk factor associated with increased cardiovascular morbidity and mortality. Although pharmacological treatment is generally well tolerated, 5%-20% of patients with hypertension are resistant to medical therapy, which is defined as blood pressure above goal (>140/90 mmHg in general; >130-139/80-85 mmHg in patients with diabetes mellitus; >130/80 mmHg in patients with chronic kidney disease) despite treatment with ≥3 antihypertensive drugs of different classes, including a diuretic, at optimal doses. These patients are at significantly higher risk for cardiovascular events, in particular stroke, myocardial infarction, and heart failure, as compared with patients with nonresistant hypertension. The etiology of resistant hypertension is multifactorial and a number of risk factors have been identified. In addition, resistant hypertension might be due to secondary causes such as primary aldosteronism, chronic kidney disease, renal artery stenosis, or obstructive sleep apnea. To identify patients with resistant hypertension, the following must be excluded: pseudo-resistance, which might be due to nonadherence to medical treatment; white-coat effect; and inaccurate measurement technique. Activation of the sympathetic nervous system contributes to the development and maintenance of hypertension by increasing renal renin release, decreasing renal blood flow, and enhancing tubular sodium retention. Catheter-based renal denervation (RDN) is a novel technique specifically targeting renal sympathetic nerves. Clinical trials have demonstrated that RDN significantly reduces blood pressure in patients with resistant hypertension. Experimental studies and small clinical studies indicate that RDN might also have beneficial effects in other diseases and comorbidities, characterized by increased sympathetic activity, such as left ventricular hypertrophy, heart failure, metabolic syndrome and hyperinsulinemia, atrial fibrillation, obstructive sleep apnea, and chronic kidney disease. Further controlled studies are required to investigate the role of RDN beyond blood pressure control. |
12,589 | Prevalence of atrial fibrillation in China and its risk factors. | To study the prevalence of atrial fibrillation (AF) and the relation with its risk factors in China.</AbstractText>A total of 19 363 participants (8635 males and 10 728 females) aged ⋝35 years in geographically dispersed urban and rural regions of China were included in this cross-sectional survey. All participants received questionnaire, physical and blood examination. Echocardiography were performed for AF patients found in the survey.</AbstractText>Of the 19 363 participants, 199 were diagnosed with AF. The estimated age-standardized prevalence of AF was 0.78% in men and 0.76% in women. The prevalence of AF in participants aged <60 years was 0.41% in men and 0.43% in women, and was 1.83% in both men and women aged ⋝60 years. About 19.0% of males and 30.9% of females with AF were diagnosed with valve disease. Age- and sex-adjusted multivariable logistic regression analysis revealed that myocardial infarction, left ventricular hypertrophy (LVH), obesity, and alcohol consumption were associated with a increased risk of AF(P<0.05).</AbstractText>The age standardized prevalence of AF is 0.77% in the participants enrolled in the present study. The number of AF cases aged ⋝35 years is 5.26 million according to 2010 Chinese Census. Most risk factors for AF, identified mainly in Western countries, are also detected in China.</AbstractText>Copyright © 2013 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.</CopyrightInformation> |
12,590 | Epicardial adipose tissue is associated with prevalent atrial fibrillation in patients with hypertrophic cardiomyopathy. | Prevalent atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) represents an important issue with regard to stroke events caused by embolization and is associated with high mortality. Increased epicardial adipose tissue (EAT), which shows high metabolic activity, can locally influence the activity of the autonomic ganglia, enhancing autonomic dysregulation and increasing the likelihood of AF. We tested the hypothesis that EAT is associated with prevalent AF in HCM patients. Sixty-two patients with idiopathic HCM diagnosed on the basis of ultrasound cardiography findings and histopathological evaluation of myocardium obtained by right ventricular biopsy underwent cardiac magnetic resonance imaging to estimate the extent of EAT. EAT area was significantly higher in the group with AF episodes than in the group without. An increased incidence of AF was found to be significantly related to an increase in EAT, and this association persisted after adjustment for body mass index, sex, and age. Time domain measures of heart rate variability measured by Holter electrocardiography, standard deviation of normal to normal, and standard deviation of the average of normal to normal were negatively related to EAT area. EAT was positively correlated with intraventricular septal thickness and cystatin C level and negatively correlated with the 24-hour creatinine clearance rate. Increased EAT area in HCM patients is significantly related to the presence of AF, which is associated with changes in baseline autonomic nervous tone, left ventricular mass, and chronic kidney disease. |
12,591 | Role of electrical storm as a mortality and morbidity risk factor and its clinical predictors: a meta-analysis. | Electrical storm (ES) is a devastating and life-threatening event in clinical practice, but its real weight as a risk factor and its clinical predictors remain unclear. Our objective was to evaluate ES as a mortality and morbidity risk factor and to define the clinical variables associated with ES.</AbstractText>The meta-analysis was performed according to the PRISMA guidelines. At the end of the selection process, 13 studies were collected and included in the quantitative analysis. Mortality and morbidity due to ES were assessed. The most acknowledged ES predictors were taken into account in separate sub-analyses. The whole cohort included 5912 patients (857 with ES). Risk of death was increased in the ES group [risk ratio (RR) 3.15; 95% confidence interval (CI) 2.22-4.48]. Electrical storm was also associated with increased composite risk of all-cause death, cardiac transplantation, and hospitalization for acute heart failure (RR 3.39; 95% CI 2.31-4.97). These results were confirmed by comparing the ES group with patients with or without previous unclustered episodes of ventricular arrhythmias. Moreover, implantable cardioverter-defibrillator (ICD) for secondary prevention, lower ejection fraction, monomorphic ventricular tachycardia as triggering arrhythmia, and class I anti-arrhythmic drugs therapy were all associated with ES.</AbstractText>Electrical storm is a strong mortality risk factor and it is associated with an increased combined risk of death, heart transplantation, and hospitalization for heart failure. Implantable cardioverter-defibrillator for secondary prevention, monomorphic ventricular tachycardia as triggering arrhythmia, lower ejection fraction, and class I anti-arrhythmic drugs therapy are all associated with ES and could be used to define specific populations with higher risk to develop ES.</AbstractText> |
12,592 | A novel KCNQ1 missense mutation identified in a patient with juvenile-onset atrial fibrillation causes constitutively open IKs channels. | Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. In some patients, the disease is inheritable; however, hereditary aspects of AF remain not fully elucidated.</AbstractText>The purpose of this study was to identify genetic backgrounds that contribute to juvenile-onset AF and to define the mechanism.</AbstractText>In 30 consecutive juvenile-onset AF patients (onset age <50 years), we screened AF-related genes (KCNQ1, KCNH2, KCNE1-3, KCNE5, KCNJ2, SCN5A). We analyzed the function of mutant channels using whole-cell patch-clamp techniques and computer simulations.</AbstractText>Among the juvenile-onset AF patients, we identified three mutations (10%): SCN5A-M1875T, KCNJ2-M301K, and KCNQ1-G229D. Because KCNQ1 variant (G229D) identified in a 16-year-old boy was novel, we focused on the proband. The G229D-IKs was found to induce a large instantaneous activating component without deactivation after repolarization to -50 mV. In addition, wild-type (WT)/G229D-IKs (WT and mutant coexpression) displayed both instantaneous and time-dependent activating currents. Compared to WT-IKs, the tail current densities in WT/G229D-IKs were larger at test potentials between -130 and -40 mV but smaller at test potentials between 20 and 50 mV. Moreover, WT/G229D-IKs resulted in a negative voltage shift for current activation (-35.2 mV) and slower deactivation. WT/G229D-IKs conducted a large outward current induced by an atrial action potential waveform, and computer simulation incorporating the WT/G229D-IKs results revealed that the mutation shortened atrial but not ventricular action potential.</AbstractText>A novel KCNQ1-G229D mutation identified in a juvenile-onset AF patient altered the IKs activity and kinetics, thereby increasing the arrhythmogenicity to AF.</AbstractText>© 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.</CopyrightInformation> |
12,593 | The role of the autonomic nervous system in cardiac arrhythmias. | Autonomic nervous system activity exerts potent and diverse effects on cardiac rhythm through elaborate neurocircuitry that is integrated at multiple levels. Adrenergic activity such as is associated with mental or physical stress or as a reflex response to myocardial ischemia is capable of generating significant rhythm abnormalities including ventricular fibrillation, the arrhythmia responsible for sudden cardiac death. With respect to the ventricles, vagus nerve activity is generally antiarrhythmic as it inhibits the profibrillatory effects of sympathetic nerve activation, whereas atrial arrhythmias generally derive from heightened levels of both vagus and sympathetic nerve activity. Containment of neural influences by pharmacological and electrical targeted neuromodulation is being pursued as an antiarrhythmic modality. |
12,594 | Transmembrane current imaging in the heart during pacing and fibrillation. | Recently, we described a method to quantify the time course of total transmembrane current (Im) and the relative role of its two components, a capacitive current (Ic) and a resistive current (Iion), corresponding to the cardiac action potential during stable propagation. That approach involved recording high-fidelity (200 kHz) transmembrane potential (Vm) signals with glass microelectrodes at one site using a spatiotemporal coordinate transformation via measured conduction velocity. Here we extend our method to compute these transmembrane currents during stable and unstable propagation from fluorescence signals of Vm at thousands of sites (3 kHz), thereby introducing transmembrane current imaging. In contrast to commonly used linear Laplacians of extracellular potential (Ve) to compute Im, we utilized nonlinear image processing to compute the required second spatial derivatives of Vm. We quantified the dynamic spatial patterns of current density of Im and Iion for both depolarization and repolarization during pacing (including nonplanar patterns) by calibrating data with the microelectrode signals. Compared to planar propagation, we found that the magnitude of Iion was significantly reduced at sites of wave collision during depolarization but not repolarization. Finally, we present uncalibrated dynamic patterns of Im during ventricular fibrillation and show that Im at singularity sites was monophasic and positive with a significant nonzero charge (Im integrated over 10 ms) in contrast with nonsingularity sites. Our approach should greatly enhance the understanding of the relative roles of functional (e.g., rate-dependent membrane dynamics and propagation patterns) and static spatial heterogeneities (e.g., spatial differences in tissue resistance) via recordings during normal and compromised propagation, including arrhythmias. |
12,595 | Screening of MYH7, MYBPC3, and TNNT2 genes in Brazilian patients with hypertrophic cardiomyopathy. | Hypertrophic cardiomyopathy (HC) is the most prevalent genetic cardiac disease caused by a mutation in sarcomeres, Z-disks, or calcium-handling genes and is characterized by unexplained left ventricular hypertrophy. The aim of this study was to determine the genetic profile of Brazilian patients with HC and correlate the genotype with the phenotype.</AbstractText>We included 268 index patients from São Paulo city and 3 other cities in Brazil and extracted their DNA from whole blood. We amplified the coding sequencing of MYH7, MYBPC3, and TNNT2 genes and sequenced them with an automatic sequencer.</AbstractText>We identified causal mutations in 131 patients (48.8%). Seventy-eight (59.5%) were in the MYH7 gene, 50 (38.2%) in the MYBPC3 gene, and 3 (2.3%) in the TNNT2 gene. We identified 69 mutations, 24 not previously described. Patients with an identified mutation were younger at diagnosis and at current age, had a higher mean heart rate and higher nonsustained ventricular tachycardia frequency compared with those without a mutation. Patients with MYH7 gene mutations had a larger left atrium and higher frequency of atrial fibrillation than did patients with MYBPC3 gene mutations.</AbstractText>The presence of a mutation in one of the genes suggests a worse prognosis. Mutations in the MYH7 gene, rather than in the MYBPC3 gene, were also related to a worse prognosis. This is the first work characterizing HC molecular epidemiology in the Brazilian population for the 3 most important genes.</AbstractText>© 2013.</CopyrightInformation> |
12,596 | Atrial natriuretic Peptide single nucleotide polymorphisms in patients with nonfamilial structural atrial fibrillation. | Atrial natriuretic peptide (ANP) has antihypertrophic and antifibrotic properties that are relevant to AF substrates. The -G664C and rs5065 ANP single nucleotide polymorphisms (SNP) have been described in association with clinical phenotypes, including hypertension and left ventricular hypertrophy. A recent study assessed the association of early AF and rs5065 SNPs in low-risk subjects. In a Caucasian population with moderate-to-high cardiovascular risk profile and structural AF, we conducted a case-control study to assess whether the ANP -G664C and rs5065 SNP associate with nonfamilial structural AF.</AbstractText>168 patients with nonfamilial structural AF and 168 age- and sex-matched controls were recruited. The rs5065 and -G664C ANP SNPs were genotyped.</AbstractText>The study population had a moderate-to-high cardiovascular risk profile with 86% having hypertension, 23% diabetes, 26% previous myocardial infarction, and 23% left ventricular systolic dysfunction. Patients with AF had greater left atrial diameter (44 ± 7 vs. 39 ± 5 mm; P < 0.001) and higher plasma NTproANP levels (6240 ± 5317 vs. 3649 ± 2946 pmol/mL; P < 0.01). Odds ratios (ORs) for rs5065 and -G664C gene variants were 1.1 (95% confidence interval [CI], 0.7-1.8; P = 0.71) and 1.2 (95% CI, 0.3-3.2; P = 0.79), respectively, indicating no association with AF. There were no differences in baseline clinical characteristics among carriers and noncarriers of the -664C and rs5065 minor allele variants.</AbstractText>We report lack of association between the rs5065 and -G664C ANP gene SNPs and AF in a Caucasian population of patients with structural AF. Further studies will clarify whether these or other ANP gene variants affect the risk of different subphenotypes of AF driven by distinct pathophysiological mechanisms.</AbstractText> |
12,597 | Morbidity and mortality in a large series of surgical patients with pulmonary metastases of colorectal carcinoma: a prospective multicentre Spanish study (GECMP-CCR-SEPAR). | Little information is available on postoperative morbidity and mortality after pulmonary metastasectomy. We describe the postoperative morbidity and mortality in a large multicentre series of patients after a first surgical procedure for pulmonary metastases of colorectal carcinoma (CRC) and identify the pre- and intraoperative variables influencing the clinical outcome.</AbstractText>A prospective, observational and multicentre study was conducted. Data were collected from March 2008 to February 2010. Patients were grouped into Groups A and B according to the presence or absence of postoperative complications. Variables in both groups were compared by univariate and multivariate analyses. P-values of <0.05 were considered statistically significant.</AbstractText>A total of 532 patients (64.5% males) from 32 hospitals were included. The mean (SD) ages of both study groups were similar [68 (10) vs 67 (10) years, P = NS). A total of 1050 lung resections were performed (90% segmentectomies or wedge, n = 946 and 10% lobectomies or greater, n = 104). Group A included 83 (15.6%) patients who developed a total of 100 complications. These included persistent air leaks in 18, atelectasis in 13, pneumonia in 13, paralytic ileum in 12, arrhythmia in 9, acute respiratory distress syndrome in 4 and miscellanea in 31. Reoperation was performed in 5 (0.9%) patients due to persistent air leaks in 4 and lung ischaemia in 1. The mortality rate was 0.4% (n = 2). Causes of death were sepsis in 1 patient and ventricular fibrillation in 1. In the multivariate analysis, lobectomy or greater lung resection [odds ration (OR) 1.9, 95% confidence interval (95% CI) 1.04-3.3, P = 0.03], respiratory co-morbidity (OR 2.3, 95% CI 1.1-4.6, P = 0.01) and cardiovascular co-morbidity (OR 2, 95% CI 1-3.8, P = 0.02) were independent risk factors for postoperative morbidity. Video-assisted surgery vs thoracotomy showed a protective effect (OR 0.3, 95% CI 0.1-0.8, P = 0.01).</AbstractText>The first episode of lung surgery for pulmonary metastases of CRC was associated with very low mortality and reoperation rates (<1%). The postoperative morbidity rate was 16%. Independent risk factors of postoperative morbidity were major lung resection and respiratory and/or cardiovascular co-morbidity. Video-assisted surgery showed a protective effect.</AbstractText> |
12,598 | Low efficacy of cardioversion of persistent atrial fibrillation with the implantable cardioverter-defibrillator. | Atrial fibrillation (AF) and heart failure are conditions that often coexist. Consequently, many patients with an implantable cardioverter-defibrillator (ICD) present with AF. We evaluated the effectiveness of internal cardioversion of AF in patients with an ICD.</AbstractText>Retrospectively, we included 27 consecutive ICD patients with persistent AF who underwent internal cardioversion using the ICD. When ICD cardioversion failed, external cardioversion was performed.</AbstractText>Patients were predominantly male (89 %) with a mean (SD) age of 65 ± 9 years and left ventricular ejection fraction of 36 ± 17 %. Only nine (33 %) patients had successful internal cardioversion after one, two or three shocks. The remaining 18 patients underwent external cardioversion after they failed internal cardioversion, which resulted in sinus rhythm in all. A smaller left atrial volume (99 ± 36 ml vs. 146 ± 44 ml; p = 0.019), a longer right atrial cycle length (227 (186-255) vs. 169 (152-183) ms, p = 0.030), a shorter total AF history (2 (0-17) months vs. 40 (5-75) months, p = 0.025) and dual-coil ICD shock (75 % vs. 26 %, p = 0.093) were associated with successful ICD cardioversion.</AbstractText>Internal cardioversion of AF in ICD patients has a low success rate but may be attempted in those with small atria, a long right atrial fibrillatory cycle length and a short total AF history, especially when a dual-coil ICD is present. Otherwise, it seems reasonable to prefer external over internal cardioversion when it comes to termination of persistent AF.</AbstractText> |
12,599 | Resuscitation with lipid, epinephrine, or both in levobupivacaine-induced cardiac toxicity in newborn piglets. | The optimal dosing regimens of lipid emulsion, epinephrine, or both are not yet determined in neonates in cases of local anaesthetic systemic toxicity (LAST).</AbstractText>Newborn piglets received levobupivacaine until cardiovascular collapse occurred. Standard cardiopulmonary resuscitation was started and electrocardiogram (ECG) was monitored for ventricular tachycardia, fibrillation, or QRS prolongation. Piglets were then randomly allocated to four groups: control (saline), Intralipid(®) alone, epinephrine alone, or a combination of Intralipd plus epinephrine. Resuscitation continued for 30 min or until there was a return of spontaneous circulation (ROSC) accompanied by a mean arterial pressure at or superior to the baseline pressure and normal sinus rhythm for a period of 30 min.</AbstractText>ROSC was achieved in only one of the control piglets compared with most of the treated piglets. Mortality was not significantly different between the three treatment groups, but was significantly lower in all the treatment groups compared with control. The number of ECG abnormalities was zero in the Intralipid only group, but 14 and 17, respectively, in the epinephrine and epinephrine plus lipid groups (P<0.05).</AbstractText>Lipid emulsion with or without epinephrine, or epinephrine alone were equally effective in achieving a return to spontaneous circulation in this model of LAST. Epinephrine alone or in combination with lipid was associated with an increased number of ECG abnormalities compared with lipid emulsion alone.</AbstractText> |
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