Acute Hemodynamic Consequences of Biventricular Pacing in Patients with Durable Left Ventricular Device Support

Background: Both Cardiac Resynchronization Therapy (CRT) and Left Ventricular Assist Device (LVAD) individually improve the prognosis of selected patients with advanced heart failure. However, the hemodynamic consequences of biventricular pacing with CRT in patients supported with an LVAD are unknown.

Methods: Short term hemodynamic effects of biventricular pacing were evaluated in a prospective cohort of LVAD patients undergoing an invasive hemodynamic study. Patients were eligible if on stable CRT pacing but not pacemaker dependent. Hemodynamic evaluation was repeated at baseline (CRT on), 10 minutes after CRT deactivation (CRT off) and 10 minutes after CRT reactivation.

Results: Ten patients were evaluated, age (mean±SD) 65±8, 50% with ischemic etiology. Patients were 146-797 days on LVAD support including Medtronic HVAD (4 patients); St Jude HeartMate2 (3 patients) or HeartMate3 (3 patients). On CRT heart rate was 65±6bpm, RA pressure 9.6±3.6mmHg, mean pulmonary pressure 21.7±5.7mmHg, mean wedge pressure 12.3±4.3mmHg and cardiac output 4.0±1.1. As a group no significant changes were noted. However individual responses were observed. CRT deactivation reversibly reduced pulmonary pressure in 3 and increased it in 1 patient; reversibly improved cardiac output in 3 patients and decreased it in two (figure).

Conclusion: This pilot study among LVAD patients suggests that CRT deactivation has variable short-term hemodynamic consequences . Therefore, it may be useful to individualize the decision to continue CRT treatment in patients supported with durable LVAD.