I am 68 yr old male, 8 weeks post AVR single bypass RCA. Complications - atrial fib ( corrected), left lung pleural effusion drained twice, and persisiting pulse rate of 118 per minute average. I am intolerant to beta blockers and am on Dilitazem 120 mg CR daily, Lasix and MicroK, iron, ASA, Warfarin, Crestor. What other meds do you suggest to reduce my heart rate. My BP averages 124/82