Effects of low dose propranolol after coronary bypass surgery

This study was performed to record the occurrence of clinically important supraventricular tachyarrhythmias (SVA) during the first eight days following coronary bypass surgery after preoperative withdrawal of various betablockers and to investigate whether low dose propranolol medication postoperatively could reduce the occurrence of such arrhythmias. Forty patients with stable angina pectoris were postoperatively randomly assigned to either a group (B) receiving low doses of propranolol or to a group (A) not receiving this medication. The number of patients having episodes of clinically important SVA was recorded. Two out of sixteen patients in the propranolol group had such episodes compared with nine out of twenty without postoperative betablockade (p = 0.07). Thus among patients treated with various betablockers which were withdrawn prior to coronary surgery, the occurrence of postoperative clinically important SVA could not be significantly reduced by postoperative low dose propranolol administration.