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Updated: Jun 10, 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
Isolated left ventricular pacing results in worse long-term clinical outcome when compared with biventricular pacing:
Kamil Sedláček1, Lucie Burianová, Hanka Mlčochová
1Clinic of Cardiology, Institute for Clinical and Experimental Medicine (IKEM), Vídeňská 1958/9, Prague, Czech Republic.
Insights
Biventricular pacing offers superior clinical and echocardiographic benefits compared to isolated left ventricular pacing in patients with idiopathic dilated cardiomyopathy. Long-term follow-up suggests biventricular pacing may reduce mortality rates.
Area of Science:
- Cardiology
- Medical Devices
- Heart Failure Management
Background:
- Idiopathic dilated cardiomyopathy (IDCM) is a significant cause of heart failure.
- Cardiac resynchronization therapy (CRT) aims to improve cardiac function in heart failure patients.
- Pacing strategies, including biventricular (BiV) and left ventricular (LV) pacing, are used in CRT.
Purpose of the Study:
- To compare the long-term clinical effects of biventricular pacing versus isolated left ventricular pacing.
- To evaluate the impact of different pacing strategies on reverse remodeling and clinical outcomes in IDCM patients.
Main Methods:
- Randomized controlled trial comparing BiV pacing with LV pacing in 40 IDCM patients indicated for CRT.
- Clinical and echocardiographic parameters assessed regularly for 1 year.
- Retrospective outcome analysis performed 4 years post-initiation, excluding patients with atrial fibrillation.
Main Results:
- BiV pacing demonstrated significantly greater improvements in left ventricular ejection fraction (12.5% vs. 5.1%) and reductions in left ventricular end-diastolic diameter (8.69 mm vs. 5.1 mm) compared to LV pacing.
- A trend towards greater overall clinical benefit was observed with BiV pacing (P=0.06).
- After 3 years, no cardiovascular deaths occurred in the BiV group, versus three in the LV group.
Conclusions:
- Biventricular pacing provides superior clinical and reverse remodeling benefits in IDCM patients undergoing CRT.
- Isolated left ventricular pacing may be associated with increased long-term mortality compared to biventricular pacing.
Aims:
The objective of this study was to compare long-term clinical effects of biventricular pacing with isolated left ventricular pacing.
Methods And Results:
Forty consecutive patients with idiopathic dilated cardiomyopathy and indication for cardiac resynchronization therapy were randomized to biventricular or isolated left ventricular pacing. Clinical and echocardiographic parameters were studied regularly prior to implantation and during 1 year of follow-up. Patients with atrial fibrillation were excluded from the study. A retrospective cross-sectional outcome analysis was performed 4 years after the beginning of the study. Biventricular pacing was associated with more pronounced clinical and echocardiographic benefit compared with left ventricular pacing. Biventricular pacing was associated with significantly more distinct reverse remodelling. Left ventricular ejection fraction improved by 12.5 per cent-points (95% CI 7.3-17.7) compared with 5.1 per cent-points (95% CI 1.1-9.2) (P = 0.01) and left ventricular end-diastolic diameter decreased by 8.69 mm (95% CI 5.2-12.2) compared with 5.1 mm (95% CI 1.5-8.7) (P = 0.05) in the biventricular and left-ventricular pacing group, respectively. Semi-quantitative summarization of response points revealed a greater benefit in the biventricular vs. left ventricular pacing group [mean sum of response points 3.25 (95% CI 2.62-3.88) vs. 2.35 (95% CI 1.74-2.96), respectively, P = 0.06]. After 3 years of follow-up, there was no cardiovascular death in the biventricular pacing group compared with three cardiovascular deaths in the left ventricular pacing group.
Conclusion:
In patients with idiopathic dilated cardiomyopathy, biventricular pacing is associated with significantly more pronounced benefit in clinical outcomes and reverse remodelling. A retrospective analysis after 3 years of follow-up suggests that isolated left ventricular pacing may be associated with a higher mortality rate compared with biventricular pacing.
