Interv Akut Kardiol. 2008;7(1):10-16

Left-ventricular pacing - an alternative of cardiac resynchronization therapy?

Lucie Riedlbauchová¹, Tomáš Marek¹, Lucie Popová¹, Věra Lánská², Hanka Mlčochová¹, Petr Peichl¹, Josef Kautzner¹

¹ Klinika kardiologie, Institut klinické a experimentální medicíny, Praha

² Oddělení statistiky, Institut klinické a experimentální medicíny, Praha

Introduction: First studies suggested that single-site left-ventricular pacing (LVP) results in acute hemodynamic benefit that is comparable to biventricular pacing (BVP). However, the long-term effects of LVP and its influence on ventricular dyssynchrony are still not well known.

Methods: In order to avoid the influence of post-infarction scar on ventricular activation, this issue was studied in patients with idiopathic dilated cardiomyopathy only. Total of 27 patients with DCM and conventional indication for CRT were included in the study. They were randomized to either BV or LVP, and their clinical and echocardiographic outcomes were studied every 3 months during the first year of CRT.

Results: The baseline characteristics were comparable between groups except larger interventricular delay in BVP group. Although both BVP and LVP were associated with improvement in NYHA class, LVP was superior to BVP since the third months of therapy. There was a trend towards sustained improvement in exercise capacity during the time in BVP. Both BVP and LVP led to a significant reduction of LV end-diastolic diameter, but the improvement was greater in BVP group. However, ejection fraction increased similarly in both groups. Both, BVP and LVP cause significant prolongation of the right-ventricular preejection period without corresponding change of the same interval in the left ventricle, thus reducing interventricular dyssynchrony. On the other hand, neither of the pacing modes changed significantly the degree of intraventricular dyssynchrony as assessed by tissue velocities or the ventricular filling time.

Conclusions: Both BVP and LVP lead to comparable clinical improvement. However, trend towards a progressive improvement of exercise capacity and reduction of left-ventricular size is visible during BVP. Both pacing modes reduce interventricular dyssynchrony in patients with idiopathic dilated cardiomyopathy.

Keywords: resynchronization therapy, heart failure, biventricular pacing, left-ventricular pacing, dyssynchrony

Published: March 27, 2008  Show citation