I agree with you 100%. I had such severe arrhythmia (atrial fibrillation) that I didn't have 3 steady beats in a row. I was tested etc..and put on beta blockers. The highest dose was required which the cardiologist said was a danger in itself and to try to lower the dose. But even reducing a bit caused the A.F. to return in full force.
I was only 45 years old and felt like an old lady. I was determined to be well again and I started my research which was before the internet...so I was in the library. I read that lower estrogen can cause arrhythmias so I got a doctor to give me estrogen (unopposed with progesterone which can lead to reproductive cancers). On the estrogen my arrhythmia stopped even after gradually getting off the beta blockers. My GP was shocked to discover I was on unopposed estrogen and prescribed progesterone to go along with the estrogen and the arrhythmia returned and required beta blockers but half the dose.
I researched some more and read that pushing the heart through aerobic exercise can steady arrhythmias. I joined a gym and did an hour of aerobics every day but Sunday. Within a month, I was off the beta blockers (gradually reducing...very important). I continued with the daily exercise for another 3 months. My cardiologist said it wouldn't last. I would soon be back. Well, here I am 25 years later with no arrhythmia. However, my heart will skip occasional beats if I drink coffee or have caffeine in any form or drink alcohol or have stimulant medications (decongestant or dental freezing) So I avoid all these things.
All this is to say that as you said, slynnb, do not put the doctor on a pedestal. I've always considered doctors as a resource with myself in charge of my case. Don't follow blindly what the doctor says without being fully informed. Do your own research and take responsibility for your own health. And make sure your sources are credible...such as the Mayo Clinic here.
What I am writing here about hormone therapy and aerobic activity working for me, you need to research and discuss with your own cardiologist.