I had SVT often when i was a teenager through young adulthood. In my late twenties I started having an odd rhythm that was much different than the very fast SVT I was accustomed to. My cardiologist at the time diagnosed me with atrial fibrillation, told me that the cause was unknown, and put me on a drug called betapace ( I think that's how you spell it). Long story short, I found out that was a drug that when taken over a long period of time had a peculiar side effect known as heart stoppage aka death. Needless to say I went to another cardiologist. Doctor Friedling in Fairfax, VA. He listened to my story, asked for my medical records to be sent over, and that afternoon he said with absolute certainty that I had an extra nerve pathway. He was right and he performed the ablation a week or so later. Wound up having to have multiple abalations, but that's another story. That said, other beta blockers don't have the side effects of betapace, but they do have side effects that I didn't want governing my life. So I opted for the ablation.