@abob
I know it is frustrating! Cardiocoversion is to correct an electrical issue. It works most of the time but does not guarantee the problem will not come back and need it again.

I have a ICD/Pacemaker. I have had my ICD go off and shock me probably 10 times over the 20 years I have had one. The ICD shock is same as cardiocoversion in that it shocks the heart back into rympthm. As you can see it does not mean the irregular heart beat or tachacaridia will not return and need a cardocoversion again or like me another ICD shock.

Asked your EP about supplements like magnesium that are routinely recommended to help with arrytmias (spell). There are many prescriptions you can take that will help the heart stay in regular rympthm also.