What Causes Involuntary Hand Movements In A Heart Patient?

I am a dentist, age 73, still practice part time. The problem I have is when I pick up a mouth mirror and hand piece and place them in the patients mouth my hand shake in involuntary with both hands. More so with the left hand. It seems that it is getting worst as time goes by. What could be the possible causes? There is no pain or discomfort and it is not just the hands it is also the forearm and possibly the upper arm and again it is worst on the left side of the body. Thanks for the in coming advice.History of medical problems from the earliest to the present. Five stents from 1995 - current. Prostate CA with surgery including minor heart attach, major heart attach one year ago, high blood pressure, pacemaker, high colestrol, low HDL. With all the meds I am on to keep me healthy I wonder if there is a problem with the meds