Re: PR low 40's....
My heart rate drops into the high 40's when resting, my Dr. said that is normal for some people. I do not know if your husbands rate is resting or just sitting down and taking the rate. If I am cleaning or busy doing things and sit down and take my rate it is in the high 60's to mid 70's.
Well conditioned people have lower heart rates from what I have read, I am not well conditioned as I am 64 years old. My husband recently had a heart attack and is on meds to keep his pulse rate low, usually is in the mid 50's at rest.
Of course it is always better to get checked by a Dr.
Myofascal pain syndrome
Arthritis, cervical and thorastic