Thank you for asking about your concerns ...
First of all as you have had increase in heart rate with exercise in the absence of chest pain , sweating , nausea or vomiting which is against angina .
So marked fluctuations in heart rate such that abrupt fall from 120 to 60 is usually not seen if pulse is checked manually .
Propranolol reduce heart rate , and while sleeping heart rate normally drops because of loss of Symphathetic tone over heart.
At this stage it would be ideal for you to have low dose of Propranolol 10 mg once a day , meanwhile you shouldnot worry about drop of heart rate while sleeping as I mentioned this is normal .
You will not faint , please donot be anxious , nothing will happen , Propranolol will stabilize your heart rate .
So relax , and wait for stress test . PCP advise to continue Propranolol is reasonable but use low dose 10 mg once a day .
Regards ***** ***** luck .
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