Radioactive iodine

I have been diagnosed with HOCM, the first person in my family to be so diagnosed. My father died from what was diagnosed as a myocardial infarction in the 1950s at age 47. Wondering if he may have had HOCM, I requested a copy of some of his records from Mayo Clinic. In reviewing those records, I discovered that it was recommended to him that he get treated with radioactive iodine for his angina pectoris and a relatively high risk of MI. Apparently this treatment is still used in at least some parts of the world. How does radioactive iodine impact angina and/or reduce the risk of MI?

Also, in those days before echocardiograms and the other sophisticated diagnostic tools, was there any result on a diagnostic work up which might be indicative of HOCM?

Thanks for your assistance!

Always curious

[CCF-M.D.-CRC]

Dear always,
It is very possible that your father did have hypertrophic obstructive cardiomyopathy (HOCM) and had sudden death from an acute arrhythmic event. This may have been diagnosed in the 1950's by direct pressure recordings in the chambers of the heart.  This was not routinely done then so he may not have had this test.

Radioactive iodine destroys the thyroid gland. The theory back then of using it in persons with angina was that by slowing down everything in the body you would decrease the work-load on the heart and thus decrease angina.  Of course you would also have all the symptoms of a low thyroid level as well. Clearly this was not the best way to treat angina.   Radioactive iodine is used today only in cases of overactive goiter.