Abstract

Introduction The complications and limitations of biventricular pacing largely relate to left ventricular (LV) pacing. We tested an alternative approach of simultaneously pacing the right ventricular (RV) apex and outflow tract (RVOT) or bifocal right venntricular pacing (BRVP) to provide cardiac resynchronization.

Methods 21 consecutive patients with heart failure and severely impaired LV function were studied. Ejection fraction and tissue Doppler data were collected at baseline, during BRVP and biventricular pacing using a temporary pacing protocol.

Results BRVP was achieved in all patients without complication. BRVP significantly reduced mean baseline intra LV, inter LV-RV and global mechanical dyssynchrony from 71 ± 35 to 44 ± 18ms, p=0.003; 86 ± 42 to 57 ± 33ms, p=0.029; and 157 ± 67 to 101 ± 42ms, p=0.005 respectively; and increased ejection fraction from 21 ± 8 to 29 ± 7%, p=0.002. Compared with BRVP, reductions in intra LV, inter LV-RV and global mechanical dyssynchrony were superior with biventricular pacing (31 ± 12ms, p=0.014, 36 ± 27ms, p=0.008 and 67 ± 34ms, p=0.01 compared with BRVP respectively); but improvements in ejection fraction were similar (26 ± 9%, p=NS).

Conclusions In patients with heart failure, superior mechanical resynchronization is achieved with biventricular pacing compared with BRVP. BRVP may be useful when LV lead placement is not possible.