A pilot study of systolic dyssynchrony index by real time three-dimensional echocardiography and Doppler tissue imaging parameters predicting the hemodynamic response to biventricular pacing in the early postoperative period after cardiac surgery.
OBJECTIVE
To evaluate systolic dyssynchrony index (SDI) measured by real time three-dimensional echocardiography (RT3DE) and Doppler tissue imaging (DTI) dyssynchrony parameters in predicting the hemodynamic response to biventricular (BIV) pacing in the early postoperative period after cardiac surgery. To compare right ventricular (RV) and BIV pacing using invasively measured hemodynamic values.


METHODS
A prospective randomized clinical study enrolling 11 patients with ischemic heart disease, concomitant valvular heart disease, and left ventricular ejection fraction (LVEF) ≤ 35% comparing preoperative SDI by RT3DE and DTI LV dyssynchrony parameters to hemodynamic values obtained during RV or BIV sequential (DDD) epicardial pacing in the first 72 hours after cardiac surgery.


RESULTS
BIV pacing produced a statistically significant higher cardiac output (CO) (6.27 ± 1.55 L/min) and cardiac index (CI) (3.44 ± 0.93 L/min per m(2) ) than RV pacing (CO 5.44 ± 0.97 L/min, CI 3.03 ± 0.83 L/min per m(2) , P < 0.05). We found a statistically moderate correlation between preoperative SDI by RT3DE and CO (r = 0.596, P < 0.05) and a nonsignificant correlation to CI (r = 0.535, P < 0.10) during BIV pacing. No correlation was observed between DTI dyssynchrony parameters and measured hemodynamic values. BIV pacing reduced the ICU stay and inotropic support requirements of patients after heart surgery.


CONCLUSIONS
SDI measured preoperatively using RT3DE can predict CO during BIV pacing in the early postoperative period after cardiac surgery. BIV pacing is more hemodynamically effective than RV pacing in patients with LV dysfunction after coronary artery bypass grafting with or without a valve procedure.