Dual-chamber pacing with His bundle pacing has theoretical advantages over conventional right ventricular (RV) apical pacing. We compared indexes of left ventricular (LV) function during acute ...dual-chamber pacing from the His bundle and other RV and LV pacing sites. Twelve patients (6 men; 63 ± 11 years) with a standard indication for electrophysiologic study were included. Average QRS duration was 100 ± 19 ms. Ejection fraction was 48 ± 15%. A pressure–volume catheter was positioned in the left ventricle through the femoral arterial access. Pressure–volume loops were collected during atrial (AAI) and dual-chamber overdrive pacing at 82 ± 15 beats/min after 2 minutes of hemodynamic stabilization. Ventricular pacing catheter position was randomized between the RV apex, RV septal, and free wall portions of the outflow tract, LV free wall, and His bundle. His bundle capture was verified from surface electrocardiographic morphometry using standard criteria. Atrioventricular delay was set to the P wave–His duration −10 ms to minimize the effects of fusion (96 ± 22 ms). LV only pacing, but not His pacing, resulted in improved stroke work and stroke volume compared with alternate site RV pacing. No changes in +dP/dt, LV end-systolic pressure. LV end-diastolic pressure, or cycle efficiency, were observed between RV pacing sites. In conclusion, acute His bundle pacing did not improve LV function compared with alternate site RV pacing and may be inferior to LV pacing.
Objectives The purpose of this study was to investigate the factors related to sex-specific outcomes for death and heart failure events in the MADIT-CRT (Multicenter Automatic Defibrillator ...Implantation Trial With Cardiac Resynchronization Therapy) trial. Background In the MADIT-CRT trial, women seemed to achieve a better result from resynchronization therapy than men. Methods All 1,820 patients (453 female and 1,367 male) enrolled in the MADIT-CRT trial were included in this sex-specific outcome analysis that compared the effect of cardiac resynchronization therapy with defibrillator (CRT-D) relative to implanted cardioverter-defibrillator (ICD) on death or heart failure (whichever came first), heart failure only, and death at any time. Results Female patients were more likely to have nonischemic cardiomyopathy and left bundle branch block and less likely to have renal dysfunction than male patients. Overall, female patients had a better result from CRT-D therapy than male patients, with a significant 69% reduction in death or heart failure (hazard ratio: 0.31, p < 0.001) and 70% reduction in heart failure alone (hazard ratio: 0.30, p < 0.001). Women had a significant 72% reduction in all-cause mortality in the total population (hazard ratio: 0.28, p = 0.02) and significant 82% and 78% reductions in mortality in those with QRS ≥150 ms and with left bundle branch block conduction disturbance, respectively, with sex-by-treatment interactions for mortality reduction significant at p < 0.05 in each of these 3 patient groups. These beneficial CRT-D effects among women were associated with consistently greater echocardiographic evidence of reverse cardiac remodeling in women than in men. Conclusions Women in the MADIT-CRT trial obtained significantly greater reductions in death or heart failure (whichever came first), heart failure alone, and all-cause mortality with CRT-D therapy than men, with consistently greater echocardiographic evidence of reverse cardiac remodeling in women than in men. (Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy MADIT-CRT; NCT00180271 ).
Background The aim of the present study was to evaluate the incidence, predictors, and related outcomes of patients with heart failure (HF) treated with cardiac resynchronization therapy with an ...implantable cardioverter defibrillator (CRT-D) who experienced electrical storm (ES). Electrical storm was defined as the occurrence of ≥3 episodes in 24 hours of sustained ventricular tachyarrhythmias. Methods A total of 631 patients with HF (90% male, mean 66 ± 9 years) consecutively received a CRT-D device. At baseline, the mean left ventricular ejection fraction was 26% ± 7%, the QRS duration was 164 ± 33 milliseconds, and the mean New York Heart Association class was 3.3 ± 0.3. Results During a mean follow-up of 19 ± 11 months, 2,419 ventricular tachyarrhythmia episodes were appropriately detected in 141 (22%) patients. Electrical storm occurred in 45 (7%) of 631 patients. Kaplan-Meier analysis and multivariable Cox regression showed that ES is more frequent in secondary prevention (hazard ratio 2.3, 95% CI 1.2-4.3, P = .015) and in nonischemic patients (hazard ratio 2.0, 95% CI 1.1-3.8, P = .028). In patients who presented ES, CRT was associated with only marginal nonsignificant improvements of New York Heart Association class and left ventricular ejection fraction. Hospitalizations and death due to HF were more frequent in patients with ES compared with those without ES, amounting to 16.8 (4.3) versus 8.6 (0.9) per 100 patient-years ( P = .018) and 7.7 versus 2.7 per 100 patient-years ( P = .014), respectively. Conclusions Electrical storm affect only 7% of CRT-D recipients and occurred more frequently in nonischemic patients with HF with biventricular implantable cardioverter defibrillators implanted for secondary prevention. Electrical storm was associated with worse HF morbidity and mortality.
Abstract Aim The aim of this study is to evaluate incidence of adverse cardiac events in patients with chest pain with or without known existing coronary disease presenting normal electrocardiogram ...(ECG) and initial troponin. Methods Prospective, nonrandomized study enrolled low-risk patients with normal ECG and troponin on admission who underwent observation and/or stress testing by unstandardized clinical judgment. Patients who experienced recurrent angina or positive ECGs or positive troponins during observation or patients with positive stress testing were admitted; otherwise, they were discharged. End Point The end points are cardiac events at short- and long-term follow-up including cardiovascular death, myocardial infarction, unstable angina, and revascularization. Results Of 5656 patients considered, 1732 with ischemic ECG were initially admitted and, therefore, excluded from the analysis; 2860 with pleuritic chest pain and normal ECG were discharged; 1064 with visceral chest pain and normal ECG were enrolled. Patients with known coronary disease (45%) were older and likely presented known vascular disease. Patients with known vascular disease, older age, female sex, diabetes mellitus, and lower chest pain score were likely managed with observation. In patients with known coronary disease as compared with patients without, overall cardiac events account for 35% vs 14%, respectively ( P < .001), as follows: in-hospital, 23% vs 10%, ( P < .001); 1 month, 4% vs 2% ( P = .133); and 9.9 ± 4.9 months, 8% vs 2%, respectively ( P < .001). Conclusions One-third of patients with chest pain with known coronary disease, negative ECG, and biomarkers were subsequently found to have adverse cardiac events. The value of this research for an emergency medicine audience could be extended to all clinicians and general practitioners beyond cardiologists.
Although cardiac resynchronization therapy (CRT) is effective in most patients with heart failure (HF) and ventricular dyssynchrony, a significant minority of patients (approximately 30%) are ...non-responders. Optimal atrioventricular and interventricular delays often change over time and reprogramming these intervals might increase CRT effectiveness. The SonR algorithm automatically optimizes atrioventricular and interventricular intervals each week using an accelerometer to measure change in the SonR signal, which was shown previously to correlate with hemodynamic improvement (left ventricular LV dP/dtmax ). The RESPOND CRT trial will evaluate the effectiveness and safety of the SonR optimization system in patients with HF New York Heart Association class III or ambulatory IV eligible for a CRT-D device. Enrolled patients will be randomized in a 2:1 ratio to either SonR CRT optimization or to a control arm employing echocardiographic optimization. All patients will be followed for at least 24 months in a double-blinded fashion. The primary effectiveness end point will be evaluated for non-inferiority, with a nested test of superiority, based on the proportion of responders (defined as alive, free from HF-related events, with improvements in New York Heart Association class or improvement in Kansas City Cardiomyopathy Questionnaire quality of life score) at 12 months. The required sample size is 876 patients. The two primary safety end points are acute and chronic SonR lead-related complication rates, respectively. Secondary end points include proportion of patients free from death or HF hospitalization, proportion of patients worsened, and lead electrical performance, assessed at 12 months. The RESPOND CRT trial will also examine associated reverse remodeling at 1 year.
Abstract Background Patients with acute atrial fibrillation with a history of mild structural heart disease could be considered for rhythm conversion. Methods Patients received intravenous ...flecainide, propafenone, or amiodarone on presentation and a second dose after 6 hours if atrial fibrillation persisted. No randomization was used, and drugs were given at the discretion of the treating physician. Primary end point was rhythm conversion within the first 6 hours from presentation. Secondary end points included rhythm conversion, time to rhythm conversion, and adverse drug effects within 24 hours. Results Among the 378 patients enrolled, 37 (10%) recovered sinus rhythm before therapy was given. Of the remaining 341 patients, 43 (13%) received flecainide, 187 (55%) received propafenone, and 111 (32%) received amiodarone. Baseline clinical characteristics were homogeneous among groups. Rhythm conversion was obtained in 87% of treated patients overall. Within 6 hours, the primary end point was achieved in a higher proportion in the flecainide and propafenone groups (72% and 55%, respectively) as compared with the amiodarone group (30%; P < .001). The mean time to the end point overall was shorter in the flecainide and propafenone groups (178 ± 227 and 292 ± 285 minutes, respectively) as compared with the amiodarone group (472 ± 269 minutes; P < .001). Length of in-hospital stay in the amiodarone group was significantly higher (26.1 ± 22.4 hours) compared with the flecainide and propafenone groups (8.9 ± 10.3 and 11.0 ± 13.8 hours; respectively; P = .001). No significant differences were found in adverse drug effects. Conclusions Flecainide and propafenone achieve rhythm control in a higher proportion of patients as compared with amiodarone within a 6-hour management.
Abstract Background Inflammatory markers are involved in heart failure (HF) pathophysiology. However, the link between these markers and reverse remodeling as well as major adverse cardiac events (HF ...death, sudden death, and unplanned cardiac rehospitalizations) in patients who undergo cardiac resynchronization therapy (CRT) has not been evaluated. Methods and Results We recorded major adverse cardiac events of 140 patients (on optimized medical therapy, left ventricular ejection fraction 29.9 ± 9.6%, New York Heart Association Class III-IV, with intraventricular dyssynchrony) who underwent CRT (enrolled since April 2004). Moreover, we evaluated before and after 6 months of CRT: interleukin-6, high-sensitivity C-reactive protein, New York Heart Association class, quality of life (score on Minnesota Living with Heart Failure questionnaire), 6-minute walking test, left ventricular end-diastolic and end-systolic volumes (nonindexed and indexed by body surface area), and left ventricular ejection fraction. Adverse cardiac events were observed in 40 patients (28.6%): 22 deaths and 18 cardiac unplanned rehospitalizations. Only patients without adverse events during follow-up showed a significant reduction of inflammatory markers and left ventricular volumes (reverse remodeling), despite a significant improvement of clinical status observed in both groups of patients. Conclusions The reduction of inflammatory status seems to be linked to reverse remodeling as well as to a better clinical prognosis in patients with HF who underwent CRT.
Background Atrial fibrillation (AF) is associated with increased morbidity and mortality in patients suffering from heart failure (HF). Patients in New York Heart Association HF classes III or IV, ...with systolic dysfunction and a wide QRS, are candidates for cardiac resynchronization therapy (CRT), and might benefit from atrial overdrive pacing (AOP). Methods The Management of Atrial fibrillation Suppression in AF-HF COmorbidity Therapy (MASCOT) trial enrolled 409 CRT device recipients (79% men), who were randomly assigned to AOP ON (n = 197), versus AOP OFF (n = 197) and followed up for 1 year. Their mean age was 68 ± 10 years, left ventricular ejection fraction 25 ± 6%, QRS duration 163 ± 29 milliseconds. New York Heart Association class III was present in 86% of patients and 19% had a history of paroxysmal AF. The primary study end point was incidence of permanent AF at 1 year. Results Atrial overdrive pacing increased the percentage of atrial pacing from 30% to 80% ( P < .0001), was well tolerated, and did not interfere with ( a ) delivery of CRT (95% mean ventricular pacing in both groups), ( b ) response to CRT (70% responders in the control vs 67% in the treatment group), or ( c ) cardiac function (left ventricular ejection fraction increased from 24.5% ± 6.2% to 32.7% ± 10.9% in the control and from 25.8% ± 6.8% to 33.1% ± 12.6% in the treatment group). The incidence of permanent AF was 3.3% in both groups. By logistic regression analysis, a history of AF ( P < .001) and absence of antiarrhythmic drugs ( P = .002) were associated with permanent AF. Conclusions In this first trial of a specific AF prevention algorithm in CRT recipients, AOP was safe and did not worsen HF. The prevention algorithm did not lower the 1-year incidence of AF.
Three patients, who were admitted for acute decompensation of end-stage congestive heart failure (CHF), underwent nocturnal polysomnography (PSG) before, and from 7 to 80 days after, left ventricular ...assist device (LVAD) implantation. Moderate to severe sleep-disordered breathing (SDB) was diagnosed in all 3 patients within 48 hours of admission, consisting predominantly of Cheyne-Stokes breathing (CSB) with central sleep apnea. After LVAD implantation, despite improved hemodynamics and end-organ function, the patients continued to have moderate or severe CSB, although there was decreased time in CSB in 2 of them. These data suggest that optimization of hemodynamics and end-organ function with LVAD implantation in patients with acutely decompensated heart failure does not acutely reverse the central mechanisms underlying the diathesis for this CSB in this setting, nor does it protect patients from the potential morbidity associated with such SDB when CSB and decompensated heart failure co-exist.
Objectives We investigated whether the reverse remodeling after cardiac resynchronization therapy (CRT) might reduce the occurrence of ventricular arrhythmias (VAs). Background It is currently ...debated whether CRT has an effect on the burden of VAs. Methods The study included 398 patients treated with a CRT defibrillator and with a follow-up of at least 12 months. Spontaneous VAs detected by the device were reviewed and validated. Results A significant reduction in VA episodes and shock therapies was evident during the follow-up with greater decrease after 1 month. After 6 months of CRT, 227 patients (57%) showed a reduction in end-systolic volume of ≥10% and were defined as “responders.” The baseline characteristics were similar between the responders and the nonresponders. Nonetheless, the proportion of patients with recurrence of VA after 1 month of CRT was significantly lower in responders (32% vs. 43%, p = 0.024). Among baseline variables no parameters emerged as predictors of tachyarrhythmia recurrence. However, receiver-operating curve analysis recognized a reduction of left ventricular end-systolic volume at 6 months of 13% as the best cutoff to identify the reduction of VAs (with a sensitivity of 58% and a specificity of 54%). Conclusions In patients treated with CRT defibrillators, a reduction in ventricular arrhythmic events occurs during the initial 12 months after implant and is correlated with the degree of ventricular remodeling induced by the therapy. Patients demonstrating reverse remodeling at midterm follow-up show a reduction in arrhythmias soon after the implant, pronounced improvements at long-term, and a better survival.
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