Did you have a shortage of Mag/Potassium before taking the supplements? Were you taking Mag/ Potassium depleting meds?
What sort of “heart issues” did you have? Was your diet short in Mag./Potassium? None of these things would be answered by a stress test. If you had a treatable condition that could be helped by additional minerals then by all means take them but since I don’t suffer from those problems my taking your supplement would be wasted money.
If having enough vitamins makes a person healthy having twice enough will not make them any healthier.
My diet was balanced but obviously lacked what I needed for magnesium and postassium.
I don’t think many people believe taking massive doses will make them healthier, just give them a consistent supply of what their body needs to heal itself and operate efficiently. For example, I take ~120,000% of the RDA of vitamins B6 and B12. This is to provide more energy/boost metabolism which counterbalances blood sugar spiking from diabetes. The 5-hr. Energy I occasionally take on weekend outings helps greatly too. The magnesium I take is several thousand times RDA. In these cases it is the right amount for me as lower levels have noticably negative effects on my well-being.
My (very excellent) physician wholeheartedly agrees with the B suppliments and approved of the magnesium although he didn’t correlate it (or anything) with my previous heart complaints.