Beyond the prostate issues... A few personal observations, and not medical advice..
The Afib... Best to look up Afib in WebMD, for a good explanation. Basically, AFib worries concern blood flow and the threat of a clot. I have Afib, but rather than the irregular kind, mine is permanent and alway irregular. Instead of bump-de-bump-de-bump-de-bump-de-bump... it goes bump-de-bump-diddy-bump-de- bump. It's always like that. A stethoscope records it that way, all the time. For me, It's asymptomatic so I don't notice it and so far no problems.
The recommended protection is Xarelto, but that comes at a ridiculous price. Against Dr. recommendations, I just use a baby aspirin, as even with a Plan D supplement, it still comes to over $1,000/yr.
So... as for diagnosis... First, the Dr. uses a stethoscope... if the irregularities are indeed irregular, then the common check on this us the use of a Holter Harness, worn for a given period, and then used to plot out the irregular beat.
In my case, the follow up was first an EKG. After that, I was prescribed and had an echocardiogram... followed later by a Cat scan... to determine if the major heart arteries were occluded. All of this under the care of the Heart specialist.
The Echocardiogram provides a graph of how the heart actually beats. Should you get one, ask for the CD that shows the beat... this is used to determine what kind of irregularity is going on, and interesting to playback. Reading the chart is a science in itself.
You probably won't have any of these tests and scans, but it's worthwhile to understand what for most people is a mystery.
While my Afib is permanent and very regular, those with intermittent irregularities often have them "shocked" back to normal... a common event for some people.
Again... not medical advice, but a first person understanding of what is going on.
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Off topic for this, but a bit about what happened when jeanie had a TIA many years ago. What happened was a blood clot, that was in the carotid artery... blocking blood to the brain. The blood stopped on the artery of the neck, from the ear to the throat. The clot is like what happens when you have a small cut... the blood congeals and dries. Often, as in DW's case, that clot gets stuck on the way to the brain, on the wall of the artery. In her case, lucky... Florida's #1 surgeon was there on a visit. A five inch incision in the neck and then cutting into the artery itself to take out the offending clot... and stitching the artery after the removal. Very delicate.
I think this is kind of the way that heart attacks happen. The CT scan looks for damage that might have occured in (typically) the descending artery,according to the doctor. a potential location for a clot.
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For medications... We enter all of our meds into this WebMD drug interaction check, and pay very close attention to what shows up... A double check on the doctor's recommendations...
https://www.webmd.com/interaction-checker/default.htm
Sorry for rambling on, but frankly, until some of these things happened to us, I really didn't have a clue. So... observations from an amateur.