Comparison of the acute hemodynamic effect of right ventricular apex, outflow tract, and dual-site right ventricular pacing.

BACKGROUND

We studied the acute effect of pacing at the right ventricular outflow tract (RVOT), right ventricular apex (RVA) and simultaneous RVA and RVOT-dual-site right ventricular pacing (DuRV) in random order on systolic function using impedance cardiography.

METHODS

Seventy-three patients (46 males), aged 52-89 years (mean 71.4 years) subjected to routine dual chamber pacemaker implantation with symptomatic chronic II or atrioventricular block, were included to the study.

RESULTS

DuRV pacing resulted in significantly higher cardiac index (CI) in comparison to RVOT and RVA and CI at RVOT was higher than at RVA pacing (2.46 vs 2.35 vs 2.28; P < 0.001). In patients with ejection fraction >50% significantly higher CI was observed during DuRV pacing when compared to RVOT and RVA pacing and there was no difference of CI between RVOT and RVA pacing (2.53 vs 2.41 vs 2.37; P < 0.001). In patients with ejection fraction <50%, DuRV and RVOT pacing resulted in significantly higher CI in comparison to RVA pacing while no difference in CI was observed between RVOT and DuRV pacing (2.28 vs 2.21 vs 2.09; P < 0.001).

CONCLUSION

Dual-site right ventricular pacing in comparison to RVA pacing improved cardiac systolic function. RVOT appeared to be more advantageous than RVA pacing in patients with impaired, but not in those with preserved left ventricular function. No clear hemodynamic benefit of DuRV in comparison to RVOT pacing in patients with impaired systolic function was observed.