Is there a cure for repeated spells of svt?

Yes. Because most so called SVT is the result of an extra piece of "wiring" in the heart, this extra piece of wiring can be ablated (destroyed) which stops the SVT from recurring.
Yes. If medications are not successful in controlling symptoms without intolerable side effects, there is another option: ablation. This is done by an electrophysiologist (electrician of the heart). Catheters are placed through veins into the heart, abnormal pathways identified, and blocked with microwave or cryogenic burns. While not foolproof, do significantly reduce recurrences of arrhythmias.