Slow Heart Rate More Condition_symptoms What Drugs, Vitamin Supplements Or Techniques Cause Slow Heart Rate?

What drugs, vitamin supplements or techniques cause slow heart rate? - slow heart rate more condition_symptoms

I know someone who has a very slow heartbeat, but nothing really shows in the tests, but must be a device that is introduced to monitor and use the correct heart rhythm. Do drugs, vitamins and techniques, which cause a very slow heartbeat, but not on medical examinations?