Repetitive pacemaker spike during the vulnerable period in a cardiac resynchronization therapy defibrillator (original) (raw)
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Heart Rhythm, 2006
BACKGROUND Right ventricular (RV) pacing in implantable cardioverter-defibrillator (ICD) patients may have detrimental effects on morbidity and mortality, in particular by inducing heart failure (HF). OBJECTIVE We investigated whether RV pacing increases the risk of HF in an asymptomatic ICD population. METHODS We evaluated all patients without symptomatic HF who received an ICD. The primary endpoint was the occurrence of HF, which was defined as new HF, hospitalization for HF, or death due to HF. The secondary endpoint was appropriate shocks. RESULTS The study population consisted of 456 patients with mean left ventricular ejection fraction (LVEF) 40% Ϯ 13%. Mean follow-up was 31 Ϯ 22 months. Because of the bimodal distribution of pacing, patients were divided into two groups: paced Յ50% (median 0%; n ϭ 313) and paced Ͼ50% (median 96%; n ϭ 143). HF occurred more often in the paced Ͼ50% group (20% versus 9%; P Ͻ.001). Multivariate analysis identified RV pacing Ͼ50% (adjusted hazard ratio [HR] 1.85; 95% confidence interval [CI] 1.08-3.15; P ϭ .03), baseline LVEF Ͻ26% (adjusted HR 3.15; 95% CI 1.77-5.59; P Ͻ.001), angina pectoris, history of atrial fibrillation, and baseline diuretic use as independent predictors of HF. RV pacing caused more HF events in patients with LVEF Ͻ26% (n ϭ 64; 55% of paced Ͼ50% patients versus 20% of paced Յ50% patients; P ϭ .006). RV pacing Ͼ50% also independently predicted appropriate shocks (adjusted HR 1.50; 95% CI 1.02-2.20; P ϭ .04). CONCLUSION RV pacing was associated with an increased risk of HF in asymptomatic ICD patients, particularly in those with preexistent left ventricular dysfunction.
Journal of the Hong Kong College of Cardiology
CHAN ET AL.: Implantable Cardioverter Defibrillator Incorporated with Biventricular Pacing Among Heart Failure Patients. Implantable cardioverter defibrillator (ICD) with biventricular pacing (BiV) is available for drugrefractory heart failure patient who has class I indication for ICD and inter-ventricular conduction delay. We studied 32 patients with mean age of 61 years (M:F=9:1) with mean ejection fraction about 30% who has underwent implantation of implantable cardioverter defibrillator incorporated with left ventricular pacing. It showed its efficacy in terms of improvement in functional status and ejection fraction as confirmed by echocardiogram, episodes of cardiac related rehospitalization (p<0.05) and appropriate therapy for ventricular tachycardia among our patients in the mean follow up period of 22 months. Permanent left ventricular pacing is achieved by pacing of the distal branches of coronary sinus with a specially designed left ventricular (LV) lead. The optimal placement of LV lead is identified by a satisfactory pacing threshold, ventricular sensing and late sensing of LV electrical activity in order to optimize the resynchronization process. At the end of follow-up, all LV leads were fully functional with stable thresholds and appropriate sensing. Eight episodes of ventricular fibrillation and 18 episodes of ventricular tachycardia were successfully detected. The detection of ventricular arrhythmia detection was 100%. Four patients received 28 inappropriate shocks secondary to supraventricular tachycardia. Conclusion: Implantable cardioverter defibrillator incorporated with biventricular pacing is an efficient and safe mean of providing patient with cardiac resynchronization therapy in patient with drug refractory heart failure with interventricular conduction delay.
Biventricular pacing diminishes the need for implantable cardioverter defibrillator therapy
Journal of the American College of Cardiology, 2000
We sought to test the postulate that biventricular pacing diminishes the need for appropriate tachycardia therapy. We reviewed the frequency of therapy in patients, serving as their own controls, who were enrolled in the Ventak CHF (congestive heart failure) biventricular pacing study. BACKGROUND It is well established that both acute and chronic CHF contribute to the need for tachyarrhythmia therapy in recipients of an automatic implantable cardioverter defibrillator (ICD). Synchronized biventricular (BV) pacing is a new and promising therapy for symptomatic improvement of CHF in selected patients (low ejection fraction, intraventricular conduction delay). We postulate that this pacing therapy will diminish the need for tachyarrhythmia therapy.
Journal of Interventional Cardiac Electrophysiology, 2012
A 59-year-old patient with dilated cardiomyopathy, severe systolic left ventricular dysfunction and drug-refractory advanced heart failure (New York Heart Association-NYHA class III-IV symptoms) and prior history of mitral valve replacement was scheduled for implantation of a biventricular pacing system (cardiac resynchronization therapy-defibrillator or CRT-D device). The coronary sinus was cannulated after some effort and a venous coronary angiogram was performed (Panel A). Although a posterolateral cardiac venous branch (Panel A, arrow) was identified to accommodate the left ventricular pacing lead, placement of the lead in this tributary (Panel B) was accompanied by phrenic nerve stimulation, which could not be remedied by moving to more proximal positions where the lead could not be stabilized. Having no other
European heart journal, 2014
Previous studies on biventricular (BIV) pacing and cardiac resynchronization therapy-defibrillator (CRT-D) efficacy have used arbitrarily chosen BIV pacing percentages, and no study has employed implantable cardioverter defibrillator (ICD) patients as a control group. Using Kaplan-Meier plots, we estimated the threshold of BIV pacing percentage needed for CRT-D to be superior to ICD on the end-point of heart failure (HF) or death in 1219 left bundle branch block (LBBB) patients in the MADIT-CRT trial. Patients were censored at the time of crossover. In multivariable Cox analyses, no difference was seen in the risk of HF/death between ICD and CRT-D patients with BIV pacing ≤90% [HR = 0.78 (0.47-1.30), P = 0.344], and with increasing BIV pacing the risk of HF/death was decreased [CRT-D BIV 91-96% vs. ICD: HR = 0.63 (0.42-0.94), P = 0.024 and CRT-D BIV ≥97% vs. ICD: HR = 0.32 (0.23-0.44), P < 0.001]. The risk of death alone was reduced by 52% in CRT-D patients with BIV ≥97% (HR = 0....
Journal of The American Academy of Nurse Practitioners, 2004
An estimated 5 million people in the United States have heart failure (HF; American Heart Association [AHA], 2003). Although advances in medication therapy have decreased morbidity and improved survival in HF patients, many patients have refractory symptoms or are unable to tolerate these medications. In addition, the risk of sudden cardiac death (SCD) from arrhythmias remains high in this population. Surgical interventions, such as heart transplantation or the use of ventricular assist devices, are available to only a very limited number of patients (AHA). New pacing strategies, such as cardiac resynchronization therapy (CRT) and expanded use of automatic implantable cardiac defibrillators (AICDs), can improve quality of life and survival rates in HF patients refractory to medical therapy. This article will discuss the history and use of cardiac pacemakers and AICDs in appropriate HF patients and the influence of these devices on morbidity and mortality. This article will also cover management implications for primary care providers. CARDIAC RESYNCHRONIZATION THERAPY Background Cardiologists have experimented with a variety of pacing strategies to best enhance cardiac function. Initial research conducted in the early 1990s focused on optimizing atrioventricular (AV) conduction in an attempt to reduce AV valve regurgitation and to prolong ventricular filling times. Several small observational studies demonstrated shorter mitral and tricuspid valve regurgitation times, prolonged left ventricular (LV) filling times, increased cardiac output, and improved exercise tolerance in patients whose AV delays were shortened using dual chamber (DDD) pacing (
Heart, 2014
Objective Studies have shown beneficial effects of cardiac resynchronisation therapy (CRT) on mortality among patients with heart failure. However the incremental benefits in survival from CRT with a defibrillator (CRT-D) are unclear. The choice of appropriate device remains unanswered. Method This is a single-centre observational study in a tertiary cardiac centre. Patients (n=500) implanted with a CRT device with pacing alone (CRT-P) (n=354) and CRT-D (n=146) were followed for at least 2 years (mean 29 months, SD 14 months). The primary end point was all-cause mortality. Results A total of 116 deaths (23.2%) were recorded: 88 (24.8%) and 28 (19.2%), in the CRT-P and CRT-D groups, respectively. At 1 year there was a trend favouring CRT-D (HR 0.54, 95% CI 0.27 to 1.07, p=0.08) but this was attenuated by the 2nd year and became insignificant at the end of follow-up (HR 0.76, 95% CI 0.50 to 1.170, p=0.21). There was no survival benefit from having an internal cardioverter-defibrillator if patients were deemed non-responders to CRT. 27% of the CRT-P patients with ischaemic cardiomyopathy met indications for potential internal cardioverter-defibrillator implantation for primary prevention. These were older patients with poorer baseline function in comparison with CRT-D patients with devices for primary prevention. Once these differences were adjusted for, there was no difference in outcome between the groups. Conclusions CRT-D did not offer additional survival advantage over CRT-P at longer-term follow-up, as the clinical benefit of a defibrillator attenuated with time. Further work is needed to define which subset of patients benefit from CRT-D.