Objective: To examine whether preoperative treatment with diltiazem could ameliorate left ventricular (LV) diastolic dysfunction in patients after coronary artery bypass graft (CABG) surgery.
Design: Prospective, nonrandomized clinical study.
Setting: University hospital.
Participants: Thirty-four patients with preserved LV function undergoing elective CABG surgery.
Interventions: According to medical history, patients were divided into 2 groups: patients not receiving diltiazem (n = 17) and patients treated with once-daily oral diltiazem for at least 2 weeks (n = 17). All patients received preoperative beta-blockers.
Measurements and main results: After induction of anesthesia, after sternal closure, and 4 hours after cardiopulmonary bypass (CPB), mitral and pulmonary venous flow velocities were measured with pulsed Doppler. LV short-axis end-diastolic area by Doppler transesophageal echocardiography (TEE) and hemodynamic variables were obtained simultaneously at comparable pulmonary capillary wedge pressures. Postoperatively, increased peak E and A velocities were observed in patients with diltiazem and controls and returned to baseline 4 hours post-CPB in controls. Changes in these velocities did not result in a decreased E/A ratio. Peak A velocity, E/A ratio, and E wave deceleration time were significantly dependent on heart rate, not peak E velocity. End-diastolic area at comparable pulmonary capillary wedge pressure remained unchanged. In relation to diltiazem, only peak A velocity and time velocity integral of the A wave (TVI-A) at 4 hours post-CPB differed from controls.
Conclusion: Diastolic function is preserved after CABG surgery and is not altered by diltiazem in patients with preserved LV systolic function. The persistence of increased peak A velocity and TVI-A into the postoperative period suggests improved atrial systolic function with diltiazem.
Copyright 2001 by W.B. Saunders Company