Can severe stress cause the heart to beat faster and would this lead to the heart wearing out earlier? my resting heart beat is 80 to 90. what test would show heart age as compared to real age?

Stress : The body's response to stress is to stimulate the adrenal gland which releases epinephrine which causes your heart beat faster. It also causes other issues. If this is done over a long period of time there are possible side effects that can affect your heart over a long period of time, like elevating your blood pressure. You should see your doctor for a more complete evaluation.