The impact of atrio-biventricular pacing on hemodynamics and left ventricular dyssynchrony compared with atrio-right ventricular pacing alone in the postoperative period after cardiac surgery.

OBJECTIVES

The aims of this study were to test the hypotheses that in the postoperative period after coronary artery bypass graft surgery (1) atrio-right ventricular (RA-RV) pacing induces a decrease in cardiac output compared with RA pacing alone and (2) atrio-biventricular (RA-BiV) pacing improves CO compared with RA-RV pacing.

DESIGN

A prospective observational study.

SETTING

A single-center university hospital.

PARTICIPANTS

Patients referred for coronary artery bypass graft surgery.

INTERVENTIONS

Patients were studied during atrial, RA-RV, and RA-BiV pacing. Cardiac output (echocardiography) and left ventricular dyssynchrony were assessed at each step.

MEASUREMENTS AND MAIN RESULTS

RA-RV pacing induced a significant decrease in cardiac output (4.3 +/- 1.0 to 3.7 +/- 0.8 L/min, p < 0.01) and a significant increase in left ventricular dyssynchrony (13 +/- 12 to 80 +/- 25 milliseconds, p < 0.01). Biventricular pacing induced a significant increase in cardiac output (3.7 +/- 0.8 to 4.5 +/- 1.0 L/min, p < 0.01) and a significant decrease in left ventricular dyssynchrony compared with right ventricular pacing (80 +/- 25 to 21 +/- 16 milliseconds, p < 0.05).

CONCLUSIONS

RA-BiV pacing improves cardiac output compared with RA-RV pacing in the postoperative period after coronary artery bypass graft surgery. This improvement is related to an improvement in left ventricular synchronicity.