text: Most "heart patient's" sleep with their feet elevated.  LOL.   I have a bad heart.  I sleep anyway I want.  I've had stints.  Doesn't matter if you sleep on the right or left.  What you want is to allow the heart to pump blood with least resistance.  Heart patient's have problems with their legs swelling.  Of course you want to make sure their breathing is not obstructed, this is best done on their back with legs eleveate and soft pillow just under shoulder and head for comfort.  Nice if the bed is adjustable and you can keep the legs above the heart.