ADMINISTRATION OF NEBIVOLOL AFTER CORONARY-ARTERY BYPASS IN PATIENTS WITH ALTERED LEFT-VENTRICULAR FUNCTION

This prospective, double-blind study used invasive monitoring and echo -Doppler techniques to compare the hemodynamic effects of nebivolol, a new beta1-selective beta-blocking agent with those of atenolol in pat ients recovering from coronary artery bypass grafting surgery. Five mi lligrams nebivolol and 50 mg atenolol equally decreased heart rate (HR ) and blood pressure (BP) but, nebivolol, in contrast to atenolol, cau sed no decrease in stroke index (SI), cardiac index (CI), and right ve ntricular ejection fraction (RVEF). These differences appeared to be r elated in part to different peripheral effects of the two agents becau se nebivolol administration was associated with a reduction in systemi c vascular resistance (SVR). After less-than-or-equal-to 10 days of tr eatment, acceleration of aortic flow velocity increased and isovolumic relaxation time decreased with nebivolol but not with atenolol treatm ent. Both drugs were equally well tolerated. Therefore, nebivolol shar es most of its effects with classical beta1-blockers but is devoid of the potentially harmful effects on cardiac output (CO) and peripheral resistance.