Ventricular resynchronization therapy by direct His-bundle pacing using an internal cardioverter defibrillator

Abstract

Cardiac resynchronization therapy (CRT) has been demonstrated to improve the functional class of patients with refractory heart failure if QRS width is >120 ms. Addition of an internal cardioverter defibrillator diminishes the prevalence of mortality of such patients. The technique for CRT requires selective stimulation of the left ventricle (LV), commonly undertaken through the coronary sinus. This procedure is not always feasible. Direct His-bundle pacing (DHBP) might be an alternative for CRT. Patients were selected from a population with refractory heart failure derived for CRT and internal cardioverter defibrillator insertion. Of those, patients in whom LV stimulation via the coronary sinus was not achievable and DHBP obtained left bundle branch block disappearance were included. Direct His-bundle pacing corrected basal conduction disturbances in 13 of the 16 patients (81%) selected. In four patients in whom DHBP was attempted, the electrode was not successfully fixed. In the nine remaining patients, a definitive resynchronization by DHBP was achieved, with consequent improvement in functional class and parameters of LV function as assessed by echocardiography. Direct His-bundle pacing might be an alternative treatment for CRT in selected cases.