Summary

Patients with high-grade atrioventricular (AV) block and preserved baseline left ventricular (LV) function who need a high percentage of right ventricular (RV) pacing show small but significant reductions in LV ejection fraction (LVEF) over a 2-year period from pacing with either RV apex (RVA) or RV high septum (RVHS), with no difference between RVA and RVHS. This article presents results of the Protection of Left Ventricular Function During Right Ventricular Pacing [PROTECT-PACE; NCT00461734], a randomized, prospective, international, multicenter, single-blinded trial to compare the effect of pacing the RVA versus the RVHS on LV systolic function in patients with high-grade AV block.