Outlaw,
We tend to focus into catastrophic thinking over any ailment. I was born with my heart murmur/MVP, diagnosed when went for major surgery at age 7 by a cardiologist (surgery wasnt heart related, but they do work-ups prior to anesthesia,etc.
Anyway, the precautions with penicillin, amoxicillin didnt come about till around 10 years ago when seeing a dentist having MVP. You may or may not have MVP, since one of two doctors hears the click, the other doesnt. Mine has since been heard by generally all doctors I have ever been too. But to ease your mind some, prior to requirement that dentist must ask if has MVP or heart murmurs, I had braces when I was 11, which required monthly visits, and extraction of teeth, and wisdom teeth after the braces, all this during the time when NO penicillin was required.
I am 41 years old now, have had panic disorder off and on for 13 years. Upon my first attack, I too, focused on my heart, because it raced, and palpitated so badly during my attacks, I thought sure it was going to give me a heart attack, I had the shortness of breath with attacks too. It obessed me so much I paid out of pocket to a cardiologist to see if I had damage, anything, I was 28 at the time. Everything was ok, still the benign heart murmur. If you have had an EKG done, it would have picked up irregular T waves, etc. if you have any heart related problems going on now. Basically once you get that last tooth out, and then over the amoxicillin, you will let this pass too.
Trish