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Updated: Aug 29, 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
[Results of intraventricular resynchronization in patients with severe cardiac failure]
René Asenjo1, Mario Zapata, Ivonne Aramburú
1Unidad de Arritmias, Centro Cardiovascular, Hospital Clínico, Facultad de Medicina, Universidad de Chile. cenaar@ns.hospital.uchile.cl
Background:
Intraventricular resynchronization with pacemakers is a promising therapy for patients with refractory cardiac failure and intraventricular conductions delay. However its long term effects are not well known.
Aim:
To report the results of this therapy in patients with cardiac failure.
Patients And Methods:
Fourteen patients (11 male), whose mean age was 68 years, with a severe and refractory cardiac failure, have been treated in our unit using intraventricular resynchronization with pacemakers. Eight had a coronary heart disease and six a dilated myocardiopathy. The pacemaker was implanted transvenously, with conventional stimulation in atrium and right ventricle. The left ventricle was stimulated through an epicardial vein, accessed through the coronary sinus.
Results:
In one patient the high thresholds did not allow a left ventricular stimulation. In the other 13 patients, a clinical improvement was observed in 11 (85%), that has been sustained for a mean of 8.2 months. The ejection fraction improved form 23.5 to 32.4% (p < 0.001), the 6 min walking test improved from 347 to 437 m (p = 0.003) and the functional capacity changes from 3.3 to 2.7 (p < 0.001). Three patients died during follow up. One was the patient in whom the stimulation failed and two had a sudden death. No complications of the procedure were observed.
Conclusions:
In this series, intraventricular resynchronization with pacemakers was effective in 11 of 13 patients, improving functional capacity and ejection fraction. Sudden death could be avoided adding a defibrillator to the pacemaker system.
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