My GP checked my BP readings that would have been taken over the years and they were never high. Cardiologist asked if direct family had a history and if not he said it’s blood pressure .
My GP said my blood pressure would have to be high for years to cause it. He also said blood pressure doesn’t cause it , if the potential for it is there , it aggravates it.
I don’t smoke , did a little a few years ago for about a year , maybe 3 or 4 a day during a stressful time at home . And when I was a young adult would smoke when I went out but never outside that and that was over 30 years ago . Again I would think I’d have to be a fairly regular 10 to 20 a day for years to cause it .
So maybe a predisposition there ?