Comparison of temporary bifocal right ventricular pacing and biventricular pacing for heart failure: evaluation by tissue Doppler imaging.

BACKGROUND: The complications and limitations of biventricular pacing largely relate to left ventricular (LV) pacing. An alternative approach was tested of simultaneously pacing the right ventricular (RV) apex and outflow tract (RVOT) or using bifocal right ventricular pacing (BRVP) to provide cardiac resynchronisation.

METHODS: 21 consecutive patients with heart failure and severely impaired left ventricular function were studied. Ejection fraction and tissue Doppler data were collected at baseline, during BRVP, and during 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 (mean (SD)) 71 (35) to 44 (18) ms, p = 0.003; 86 (42) to 57 (33) ms, p = 0.029; and 157 (67) to 101 (42) ms, p = 0.005, respectively. It increased the 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 (12) ms, p = 0.014; 36 (27) ms, p = 0.008; and 67 (34) ms, p = 0.01 compared with BRVP, respectively); improvements in ejection fraction were similar (26 (9)%, NS).

CONCLUSIONS: In patients with heart failure, superior mechanical resynchronisation is achieved with biventricular pacing compared with BRVP. BRVP may be useful when left ventricular lead placement is not possible.