Since there is always anxiety about engaging in sex after a heart attack, 
the American Heart Association has issued guidance on how patients should be advised.
I find the following two aspects of the guidelines interesting:
- During sex, patients should be encouraged to assume their usual sexual  positions, or one that is comfortable. Those who've had coronary artery  bypass surgery are recommended to avoid being "on top" as this may  require more exertion, and to use pillows for support if needed.
- Having an affair, or having sex in an unfamiliar environment, may be a  cause of stress for the patient.  This is not the time to  be having sex with a new partner, or in a hotel room.