At rest, the human heart beats 60 to 100 times a minute, and each beat leaves us vulnerable to a heart-stopping occurrence known as "commotio cordis." An organized heartbeat is the result of
a finely-choreographed flow of electricity through the heart. Following the moment of peak electrical activity, when the heart pumps blood out to the body, there is a split second where the
heart begins to "reset" and becomes unstable. It's at this point that the heart is critically vulnerable to outside interference such as a hit to the chest from a ball, hockey-puck or
even a fist. A direct hit over the heart at this brief moment can cause the previously organized rhythm to go haywire, causing the heart to lose the ability to pump blood effectively.
This results in almost immediate collapse and cardiac arrest. While this combination of events is very rare, it is, unfortunately, usually fatal.