Acute hemodynamic benefits of biventricular and single-site systemic ventricular pacing in patients with a systemic right ventricle

BACKGROUND Patients treated by atria L redirection surgery (Senning or Mustard procedure) for transposition of the great arteries (TGA) have an important risk for heart failure caused by dysfunction of the systemic right ventricle. Conventional nonsystemic ventricular pacing (non-systVP) may even further increase this risk. OBJECTIVE We investigated the effects of endocardial non-systVP, biventricular pacing (BiVP), and singe-site systemic ventricular pacing (systVP) on systolic cardiac pump function in patients with TGA and status post atrial redirection surgery (SenningMustardTGA). METHODS During clinically indicated catheterization in 9 patients with SenningMustardTGA, endocardial ventricular stimulation (overdrive DDD mode; 80-90 beats/min) was applied with temporary pacing Leads at the nonsystemic and the systemic ventricle. Acute changes in the maximal rate of pressure rise (dP/dt(max)) and systolic pressure of the systemic ventricle, as induced by non-systVP, systVP, and BiVP compared to reference, were assessed with a pressure wire within the systemic ventricle. Reference was AAI pacing with a similar heart rate (n = 7) or non-systVP at a Lower heart rate than that during stimulation at experimental sites (85 beats/min vs 90 beats/min; n = 2). RESULTS Systemic dP/dt(max) and systolic ventricular pressure were significantly higher during systVP (+15.6% and +5.1%, respectively) and BiVP (+14.3% and +4.9%, respectively, compared with nonsystVP). In 6 of 7 patients, systemic dP/dt(max) was higher during BiVP and systVP than during AAI pacing. CONCLUSIONS In a population of patients with SenningMustardTGA, acute hemodynamic effects of endocardial systVP and BiVP were significantly and equally better than those of non-systVP. In some patients, systVP and BiVP might even be better than ventricular activation by the intrinsic conduction system.