@vjs003
I am only passing on my experience with this. They call it heart focus. When you have heart issues your mind fixation is on your heart. You will feel heart beating much more than if not heart focussed.

I am not saying what you are feeling or you personally but what I was told was happening to me. I know it but when heart flares up and have a lot of PVCs or tachycardia my mind focusses on my heart beat and can feel it. I know when not having issues don't do this but is just a natural thing for your mind to do.

Metoprolol is a good medication. I take something similar Mexiletine. Talked to your doctors about magnesium taurate. It is another type of magnesium that has been shown to be beneficial also. What I do it take both types, the glycinate and the taurate (just started the taurate) so will not know if helps. But I split my recommended by my EP 400 mg of magnesium to two different forms.