This is a rare and serious heart issue that can affect young, healthy people. It's triggered by a sudden, blunt impact to the chest. If this happens at just the right time during the heartbeat cycle (and in just the right place on the lower left side of the heart), it affects the heart's electrical signals. These are the signals that control the heartbeat. With commotio cordis, the heart muscle begins to flutter. The person's blood stops circulating properly. They lose consciousness. We call this "cardiac arrest." Without fast medical help, they will die.
What causes commotio cordis? Most often, it happens to young male athletes who play sports that put them at risk for a chest impact. A baseball, lacrosse ball or hockey puck hitting the chest can trigger it. It can happen to football players and to people who practice martial arts. It doesn't take a severe blow to cause commotio cordis. The hit may not seem serious to those who see it.
What are the symptoms? Within seconds of the chest impact, the person stumbles and falls. They lose consciousness. You may not be able to detect their pulse. And they may stop breathing.
How do we treat it? Call for emergency medical help immediately. While you wait, give the person chest compressions to move blood through their body. If you have access to a defibrillator, use it to restart their heart. With fast action, you can help save their life.