My 14 year old son has been diagnosed with SVT. I am wondering if the suggestions that you make in the post you linked above for heart palpitations would apply to this issue. If not, could you suggest alternative approaches, please? I am hoping to avoid medications or invasive procedures to correct this problem, which are the choices (along with doing nothing) that have been suggested by the cardiologist.
If you can find it I would recommend the cactus grandiflorus (night blooming cereus), which is a weak cardiac glycoside source. It will slow the heart, increase contractile force and increase circulation. Generally it is only available in a tincture form, but you can easily get your own in the future to make your own tincture. Night blooming cereus is the base cactus they use on those decorative grafted cacti you see in the stores.