My 60-yr old husband had coronary bypass surgery (double bypass) 3 weeks ago. He had been on atenolol for 17 years before the surgery (as a result of an MI at age 42). Immediately post op, he had been put on a different beta blocker, but at his follow up with the cardiologist this week, he was instructed to go back on his previous regimen, which included 25 mg atenolol. While he hadn t noticed any side effects before surgery, now he feels fatigued and heavy for 1 to 2 hours after he takes the atenolol and feels his heart pounding in his ears, his throat, his chest. He s starting to dread taking the atenolol, which is weird, because he was fine with it for so many years. Is this just because he s still weak from surgery, and can we anticipate that he will adjust within a short period? Any recommendations for timing would also be appreciated. He currently takes the beta blocker in the morning and the ACE inhibitor in the evening.