OBJECTIVE To investigate the effect of biventricular and high septal pacing on the normal contraction sequence of the helical ventricular myocardial band, and its impact on left ventricular function. METHODS Ten pigs (25-68 kg) underwent analysis of percent segmental shortening (SS%) by sonomicrometry, with crystals placed along the fiber orientation of the ascending, descending segments, and...

Echocardiography plays an integral role in the detection of mechanical dyssynchrony in patients with congestive heart failure and in predicting beneficial response to cardiac resynchronization treatment. In patients who derive sup-optimal benefit from biventricular pacing, optimization of atrioventricular delay post cardiac resynchronization treatment has been shown to improve cardiac output. S...

This editorial refers to ‘Safety and efficacy of programming a high number of antitachycardia pacing attempts for fast ventricular tachycardia: a prospective study’ by R.P. Martins et al., on page 1457 and ‘First inappropriate implantable cardioverter defibrillator therapy is often due to inaccurate device programming: analysis of the French OPERA registry’ by A. Leenhardt et al., on page 1465

BACKGROUND Cardiac resynchronization therapy (CRT) with biventricular epicardial (BV-CS) or endocardial left ventricular (LV) stimulation (BV-EN) improves LV hemodynamics. The effect of CRT on right ventricular function is less clear, particularly for BV-EN. Our objective was to compare the simultaneous acute hemodynamic response (AHR) of the right and left ventricles (RV and LV) with BV-CS and...

Right ventricular (RV) pacing has been reported to result in ventricular dyssynchrony, heart failure, and increased mortality. Pacing associated deterioration of left ventricular (LV) systolic function has been termed pacing-induced cardiomyopathy (PICM). While upgrading to biventricular pacing (BiVP) is an effective therapy for PICM, permanent His-bundle pacing (HBP) can be a physiological alt...

Introduction Cardiac resynchronization therapy (CRT) with left ventricular (LV)-only pacing has emerged as an alternative to biventricular (Bi-V) pacing used to synchronize ventricular contraction by timing LV pacing with intrinsic right ventricular (RV) conduction. Additionally, RV pacing is minimized, improving device longevity. Despite its benefits, LV pacing may not the best modality for al...

Many heart failure specialists still believe that the pathophysiology of cardiac resynchronization therapy (CRT) is incompletely understood; however, it must be emphasized that the main effects of biventricular pacing have already been described more than a decade ago. In 1994, Cazeau et al. reported how biventricular pacing improves clinical signs and symptoms of heart failure, acutely increas...