Does the Heart Ever Rest?
The heart is a muscular organ that serves as a pump, sending blood to every part of the body. The heart is always at work, even while you sleep. If your heart were to stop for any length of time, you couldn’t live — but that doesn’t mean the heart never rests. Each “heartbeat” consists of a contracting and relaxing of the heart
Yes, the heart slows down when at reat. It slows down alot when you rsleep or are in a meditative state. Some human beings are able to conciously slow the rate of their heart beating to abnormally low levels. The heart does not, however, stop beating for any length of time as it would bring death.