Related Experiment Video
Updated: Jul 28, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
[Current aspects of defibrillator therapy in congestive heart failure]
H J Trappe1, M Meine, P Pfitzner
1Medizinische Klinik II (Schwerpunkte Kardiologie und Angiologie), Universitätsklinik Marienhospital, Ruhr-Universität Bochum, Hölkeskampring 40, 44625 Herne.
Insights
Implantable cardioverter-defibrillator (ICD) therapy benefits patients with ventricular arrhythmias and impaired left ventricular (LV) function, though survival depends on LV dysfunction severity. Aggressive heart failure treatment alongside ICDs is crucial for better outcomes.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- The efficacy of implantable cardioverter-defibrillators (ICDs) in patients with life-threatening ventricular arrhythmias and impaired left ventricular (LV) function remains an area of ongoing research.
- Left ventricular dysfunction is a critical factor influencing outcomes in patients with ventricular arrhythmias.
Purpose of the Study:
- To evaluate the long-term effects and survival rates of implantable cardioverter-defibrillator (ICD) therapy in patients with varying degrees of left ventricular (LV) dysfunction.
- To assess the impact of New York Heart Association (NYHA) functional class on mortality and ICD shock frequency.
Main Methods:
- A follow-up study of 410 patients (mean age 57 years) who received ICD implants was conducted.
- Left ventricular function was assessed using the New York Heart Association (NYHA) functional classification.
- Data on perioperative mortality, causes of death, survival rates, and ICD shock incidence were collected and analyzed over a mean follow-up of 28 months.
Main Results:
- Perioperative mortality was higher with epicardial ICD implantation (5%) compared to transvenous ( < 1%).
- Overall 3-year survival rates ranged from 92% to 96% for arrhythmic mortality across NYHA classes I-III, with 84% survival at 5-7 years for NYHA class II-III.
- 82% of patients received ICD shocks, with higher shock frequency observed in patients with more severe LV dysfunction (NYHA class III).
Conclusions:
- Implantable cardioverter-defibrillator (ICD) therapy provides survival benefits for patients with left ventricular (LV) dysfunction and ventricular arrhythmias.
- Patient survival is significantly influenced by the degree of left ventricular dysfunction.
- Aggressive management of heart failure, in addition to ICD therapy, is essential for optimizing outcomes in this patient population.
Abstract:
The beneficial effects of implantable cardioverter defibrillator (ICD) therapy in patients (pts) with life-threatening ventricular tachyarrhythmias and impaired left ventricular (LV) function is still unclear. We studied the follow-up of 410 pts (368 males, 42 females, mean age 57 +/- 11 years) after ICD implant. The LV function was assessed by the New York Heart Association functional class of heart failure (NYHA). Fifty pts (12%) were in NYHA I-II, 151 pts (37%) in NYHA II, 117 pts (29%) in NYHA II-III and 92 pts (22%) in NYHA III. Epicardial ICD implantation was performed in 209 pts (51%) and 201 pts (49%) received nonthoracotomy ICDs. Perioperatively (within 30 days after implant), 12 pts (3%) died, significantly more frequent after epicardial (11 of 209 pts, 5%) than after transvenous ICD implant (1 of 201 pts, < 1%) (p < 0.05). During a mean follow-up of 28 +/- 24 months (range < 1 to 114 months), 90 pts (23%) died: 9 pts (2%) died from sudden arrhythmic death and 5 pts (1%) suddenly, but probably not from arrhythmic causes; 55 pts (14%) died from cardiac causes (congestive heart failure, myocardial reinfarction) and 21 pts (5%) from noncardiac causes. The 3-year, 5-year and 7-year survival was 92% to 96% for arrhythmic mortality in NYHA class I, II and III compared to the 3-year survival of 94%, and a 5-year and 7-year survival of 84% in patients with NYHA class II-III. 338 pts (82%) received ICD shocks (mean incidence 21 +/- 43 shocks per pt); pts in NYHA class II (83%), class II-III (84%), class III (90%) received ICD discharges significantly more frequently than in class I-II (64%) (p < 0.05). Our data show that pts with LV dysfunction benefit from ICD therapy and that these pts survive for a considerable time after the first shock. However, survival is clearly influenced by the degree of left ventricular dysfunction and, in addition to ICD therapy, aggressive treatment of heart failure is necessary.
Related Concept Videos
Heart Failure Drugs: Inotropic Agents
Dysrhythmias VI: Management of Dysrhythmias
Heart Failure V: Medical Management
Heart Failure VI: Adjunct Therapies
Cardiomyopathy II: Dilated Cardiomyopathy
Cardiomyopathy V: Interprofessional Care

