Difibulators?

I have cardiomyopathy caused by medication which I have to stay on, no other choice. Dr wants to install a subcutaneous difib and says Im heading for a heart attack. Cant have a implanted difib/pacemaker. Question, when I have a heart attack and the defib revives me, hopefully, what happens next? Im taking medication and nothing will change about the med thats causing the problem. Do I just keep having attacks until Im not revivable or what? My cardiologist just looks at me when I ask. Im taking magneseum and other minerals, which have helped with arry and palps.

I have a complex fungal disease that will attach itself to the wires and cause more problems since the wiring goes through the arteries into the heart. The subcutaenous defib goes under the skin but not into the heart.