I took the readings to show the heart specialist at Bangkok Hospital.
I got an EKG test but the doctor didn't think I needed one, also got a copy of it, if anyone wants to see. It was the same as last year he said. He said if I wanted I could get a echocardiogram but he didn't recommend it and I got the feeling he thought I was a hypochondriac, which may well be true. Good thing, he talked to me for ages, unlike some other quacks I've seen recently. Talked about family history, my grandfather died of heart disease, my mother has atrial fibrillation, which seemingly I don't have. Basically, he said I was fit and not to worry, it could have been due to not drinking enough, or drinking too much, sodium levels I think.
I wonder if anything is psychosomatic as I did feel more dizzy the day after I bought the blood pressure monitor, and felt much better after seeing the doctor!