Significance Of Different BP Readings From Each Arm

I am curious to know if there is any medical significance in different bp readings from each arm.

In my own case there is only a one or two point difference in the figures taken from each arm. However, for a family member, there is a markedly higher systolic reading on the left arm, often 40 points higher. There is also a far higher pulse pressure on the left arm, together with a different pulse rate varying by up to 15 bpm. The readings are taken one immediately after the other.

Thank you for any suggestions.

Thank you Dr Chung for your reply. I am one on this group who respects your postings.

I was posting late at night and should have provided more background information. The family member in question had an MI 27 years ago, and currently has a 100% blockage of, I believe, the RCA. The right carotid is also 100% blocked. The usual cocktail of medication is being taken, beta-blocker, calcium channel blocker, anti-platelet, etc.

I am worried as the systolic taken on the right arm with a wrist bp monitor is frequently below 90, while the left arm systolic reading can be 40 points higher. Could the difference, both in bp and pulse be a symptom of over-medication, the past MI, or a sign of something more serious?

Thanks once again, Dr Chung.