Cardiac Resynchronization Therapy (CRT) in the early postoperative period after cardiac surgery

Abstract

Purpose: Resynchronization therapy is not commonly used in the early postoperative period for patients with left venctricular dysfunction and a history of heart failure. The objective of our project was to compare the hemodynamic effect of DDD RV pacing with DDD BIV pacing in patients with left ventricle (LV) dysfunction, who had LV mechanical myocardial dyssynchrony in the early postoperative period (within 72 hours) after cardiac surgery. Methods: We performed a prospective randomized trial to compare DDD RV pacing with DDD BIV pacing in patients with LV dysfunction, an EF below 35%, a QRS interval longer than 150 msec or between 120-150 msec, who had mechanical myocardial dyssynchrony as detected by real-time 3D echocardiography (RT3DE) in the early postoperative period (within 72 hours) after cardiac surgery. Epicardial pacing was provided by a modified Medtronic INSYNC III Pacemaker. Results: The study included 18 patients with ischemic heart disease or valvular heart disease (14 men and 4 women, average age 71 years) with LV dysfunction after cardiac surgery. Patients with biventricular (BIV) pacing had a statistically significant greater cardiac output and cardiac index (CO 6,7 l/min, CI 3,5 l/min/m2) than patients with right ventricular (RV) pacing (CO 5,4 l/min, CI 2,8 l/min/m2) (BIV v.s. RV p≤ 0,001). Conclusions: Hemodynamic monitoring in our study enabled a comparison of the two pacing modes, BIV DDD pacing versus standard RV DDD pacing, in patients after cardiac surgery as to their ability to influence cardiac output and cardiac index, which are very significant prognostic indicators in the early postoperative period. Our current results show that targeted BIV DDD pacing in patients with LV dysfunction and heart failure in the early period after cardiac surgery improved the hemodynamic parameters (CO, CI) and was significantly better than RV pacing, which worsens LV dyssynchrony.