Thanks for your question on Healthcare Magic. I can understand your concern. Yes, SVT (supra ventricular tachycardia) is very harmful and can be lethal and life threatening if not treated promptly. The damage will be add on every time there is attack of SVT. During attack, there is hypotension in the body. And this hypotension can cause damage two almost all organs mainly brain, kidneys and heart itself. So SVT should be treated. Since you are having failed ablation, you should consult cardiologist who specializes in arrhythmia (like SVT). Get down electrophysiological study and radio frequency ablation (RFA) in experienced hands. You should also take anti arrhythmia drug like diltiazem. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.