Hi there, I'm 37 and I was hospitalized for myocarditis a few months ago. Only an MRI confirmed and monitored the disease's progress until its complete disappearance 8 months after. I took aspirin and betablockers and plenty of rest. I'm back to my regular activities but I still experience occasional chest pains and palpitations like you do. I often wonder if it is physiological or if it's just the result of a constant fear that myocarditis might hit me again. My physician and cardiologist, after a blood test with normal results, said that I was just experiencing 'panic attacks' that came about my hospitalization experience and gave me a medicine called 'prazepam' ('it's from France) and another that worked longterm to calm me down. The pains eventually go away, probably because of it ---or not...
I suppose it would be difficult to take blood tests every time I feel my chest tighten and my heart go flip-flop, but I think it's the only way to make sure that it's not another heart disease! Try to ask for one when you really feel bad!
Sadly there is no way of preventing it, as I have learned. The only thing one could do is to stay positive and keep healthy to assure better recovery.