This is a pet peeve of mine; the idea that one puts one's hands over one's heart during the National Anthem. I grew up in the fifties and sixties, living exclusively on military installations, at a time when respect for the National Anthem was considered absolutely obligatory, and I was never schooled to do so; simply to stand at attention respectfully and face the flag. Placing the hand over the heart is a symbol of one's fealty to a pledge or an oath, not respect.
Thank you! When I worked on a military installation and retreat was sounded you were to stand at attention and face the flag. When you say the Pledge of Allegiance you hold your hand over your heart.