While on Rythmol for arrythmia I began to have a very wierd palpitation when I did something real physical. With the palp was bad sharp chest pain. My EP Cardio said I was imagining it basically and nothing was wrong with me. I had him order a stress test for me Left Bundle Branch showed at 140 bpm and I have pain at onset. The pain he would say was not explainable. I then insisted my Family doctor monitor me while I walked up a hill. Very ugly recording. So my EP Cardio ordered a catheterization dye test because the stress test was not conclusive for something to cause pain. Before the procedure the Plumbing Cardio said (and I quote) "If we find blockage, you will have to stop the Rythmol immediately because it would be dangerous". Anyway I had no blockage but because of the comment I reduced the Rythmol and eventually stopped it. The chest pain and LBBB disappeared. If my EP Cardio thought I had LBBB why would he still continued the Rythmol which is contradictory. For certain things I'm sure it is a good drug but I am convinced it would have killed me. You did the right thing by checking immediately when your body was telling you something was wrong. Listen to the Forum Doc here.
If you had a heart attack, STOP the rhythmol. It is not a safe medication for someone with coronary artery disease. There are three options for people with arrhythmias and coronary artery disease -- sotalol, dofetilide, and amiodarone. If you have abnormal kidney function, amiodarone is often the only choice. You should see an heart rhythm specialist to discuss options that might work for you. it can be a tricky decision. it also depends on what the arrhythmia is.
I hope this helps and I wish you a speedy recovery.