[Is resynchronization therapy necessary when optimizing right ventricular stimulation?]

Cardiac resynchronization therapy (CRT) using biventricular stimulation is hampered by coronary venous imponderabilities, complex implantation procedures, technical malfunctions and complications as well as disappointing responder rates. Despite its pathophysiological soundness and some initial success, the use of AV sequential pacing for the treatment of heart failure has been abandoned because right ventricular (RV) apical stimulation may be detrimental for cardiac mechanics, may worsen heart failure and may increase mortality. Attempts at avoiding desynchronizing effects and improving hemodynamics by pacing from alternative RV sites have been numerous but not convincing. Whether patients with left ventricular dysfunction or overt heart failure may benefit from pacing the RV outflow tract or septum, from dual site RV or His bundle stimulation instead of left ventricular based resynchronization is the topic of this review.