Monocentric, randomized, double-blind comparative crossover clinical study.~Patients with a standard pacing indication with >20% ventricular pacing, with a baseline LVEF >40%, implanted with a functioning His bundle lead and a backup right ventricular lead, will be randomized to 6-months periods of right ventricular pacing and of His bundle pacing. The primary outcome is LVEF assessed by gated Equilibrium Radionuclide Angiography. Secondary outcomes are diastolic function, New York Heart Association (NYHA) functional class, quality of life, 6-minute walk test, heart failure hospitalisations and device electrical parameters.
This study will randomize cross-over periods of 6 months of right ventricular pacing and His bundle pacing in patients with baseline left ventricular ejection fraction (LVEF)>40%. The primary outcome measure is LVEF.