Multipoint left ventricular pacing improves acute hemodynamic response assessed with pressure-volume loops in cardiac resynchronization therapy patients

BACKGOUND Conventional cardiac resynchronization therapy (CRT) improves acute cardiac hemodynamics. OBJECTIVE To investigate if CRT with multipoint left ventricular (LV) pacing in a single coronary sinus branch (MultiPoint Pacing [MPP], St Jude Medical, Sylmar, CA) can offer further hemodynamic benefits to patients. METHODS Forty-four consecutive patients (80% men, New York Heart Association III, end-systolic volume 180 7 77 mL, ejection fraction 27% 6%, and QRS duration 152 t 17 ms) receiving a CRT device implant (Unify Quadra MP or Quadra Assura MP and Quartet LV lead, St Jude Medical) underwent intraoperative assessment of LV hemodynamics by using a pressure-volume loop system (Inca, CD Leycom). A pacing protocol was performed, including 9 biventricular pacing interventions with conventional CRT (CONV) using distal and proximal LV electrodes and various MPP configurations. Each pacing intervention was performed twice in randomized order with right ventricular pacing (BASELINE) repeated after every intervention. RESULTS Evatuable recordings were obtained in 42 patients. Relative to BASELINE, the best MPP intervention significantly increased the rate of pressure change (dP/dtmax; 15.9% 10.0% vs 13.5% t 8.8%; P <.001), stroke work (27.2% 42.5% vs 19.4% t 32.2%; P =.018), stroke volume (10.4% 7 22.5% vs 4.1% 13.1%; P =.003), and ejection fraction (10.5% 20.9% vs 5.3% 13.2%; P =.003) as compared with the best CONV intervention. Moreover, the best MPP intervention improved acute diastolic function, significantly decreasing dP/dtmir, (-13.5% 7 10.2% vs 10.6% t 6.8%; P =.011), relaxation time constant (-7.5% 7 9.0% vs 4.8 /0 t 7.2%; P =.012), and end-diastolic pressure (-18.2% 22.4% vs 8.7% t 21.4%; P <.001) as compared with the best CONV intervention. CONCLUSIONS CRT with MPP can significantly improve acute LV hemodynamic parameters assessed with pressure-volume loop measurements as compared with CONV. (C) 2014 Heart Rhythm Society. All rights reserved.