I experience Paroxysmal Atrial Tachycardia . My heart rate has been over 300 BPM, which only stops when they give me a shot in an IV of adenosine. They say it can not kill me because it is atrial, and they always send me home the same day. It has happened 5x since I was 19 (I m pushing 31 now). They suggest a cardiac ablation, which can kill me. Are the docs right ? It doesn t seem possible that a heart can beat that fast for too long with out giving up on you.