I developed side effects while taking liothyronine June 2010. Liothyronine discontinued at that time. Five months later still experiencing angina, rapid or irregular heartbeat and fatique. Symptoms have slowly improved over time. Various tests taken. Halter moniter showed extra beats of heart. EKG shows nothing. Waiting on stress test. Anyone with a similar experience? Permanant damage? Haven't recieved straight answers from docs.