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Updated: Aug 21, 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
[Cardiac resynchronization therapy for heart failure]
Augusto Achilli1, Nicolino Patruno, Daniele Pontillo
1UTIC e U.O.D. di Elettrofisiologia, Ospedale Belcolle, Viterbo.
Insights
Cardiac resynchronization therapy improves heart failure symptoms and function in many patients. However, identifying non-responders remains a challenge, with new imaging techniques showing promise.
Area of Science:
- Cardiology
- Biomedical Engineering
Background:
- Advanced refractory heart failure has a poor prognosis, linked to left ventricular dysfunction.
- Conduction delays affect nearly 50% of heart failure patients, impacting cardiac performance.
- Correcting electrical abnormalities offers a potential therapeutic avenue.
Purpose of the Study:
- To evaluate the efficacy of biventricular stimulation (cardiac resynchronization therapy) in heart failure patients.
- To identify factors influencing response to cardiac resynchronization therapy.
- To explore methods for reducing non-responder rates in cardiac resynchronization therapy.
Main Methods:
- Biventricular stimulation (cardiac resynchronization therapy) to correct mechanical asynchrony.
- Analysis of clinical trial data for patients with NYHA class III-IV heart failure, specific QRS duration, LV end-diastolic diameter, and ejection fraction.
- Utilizing Tissue Doppler imaging to assess left ventricular dyssynchrony in ongoing studies.
Main Results:
- Biventricular pacing significantly improved left ventricular performance, quality of life, and NYHA class.
- No significant impact on total mortality was observed in completed trials.
- Approximately 20-30% of patients were identified as non-responders in prior studies.
Conclusions:
- Cardiac resynchronization therapy is a valuable treatment for selected heart failure patients, improving key functional parameters.
- The identification and management of non-responders is a critical area for further research.
- Tissue Doppler imaging may help personalize therapy and reduce the percentage of non-responders.
Abstract:
The short-term prognosis of advanced refractory heart failure is extremely poor and closely correlated with progressive left ventricular dysfunction. The identification of the negative effects of conduction delay on cardiac performance, observed in almost 50% of heart failure patients, disclosed a new research field addressing the correction of electrical abnormalities in order to achieve an improvement in myocardial function. Biventricular stimulation, or cardiac resynchronization therapy, corrects the atrioventricular, inter- and intraventricular mechanical asynchrony and, to date, is indicated (class IIA, level of evidence A) for patients with NYHA class III-IV refractory heart failure regardless of its etiology, QRS interval > or = 130 ms, left ventricular end-diastolic diameter > or = 55 mm, and ejection fraction < or = 35%. To date, the completed trials demonstrated in patients undergoing biventricular pacing a significant improvement in left ventricular performance, quality of life and NYHA class with no significant effects on total mortality. The identification of non-responders (approximately 20-30% of the patient population in completed trials) represents an unresolved issue of cardiac resynchronization therapy. Tissue Doppler imaging evaluation of left ventricular dyssynchrony, which is being addressed by non-randomized prospective studies, should drastically decrease the percentage of these patients.
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