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Blunt Injury to the Heart
(Cardiac Contusion; Myocardial Contusion)
Blunt injury to the heart is a blow to the chest that bruises the heart muscle, tears (ruptures) the heart's walls, or damages a heart valve.
People may feel that their heart is pounding or racing, feel short of breath, or have dangerously low blood pressure.
Electrocardiography (ECG) and ultrasonography of the heart (echocardiography) are done.
People who have an abnormal heart rhythm (heartbeats that are too fast, too slow, or irregular) are admitted to the hospital so that the rhythm can be monitored continuously.
People who have damage to a heart valve or a tear in the heart's wall usually require surgery.
A blunt injury is a forceful blow that does not penetrate the skin. Blunt injuries to the heart can be caused by a motor vehicle crash, a fall from a height, or less often a direct blow.
If the heart is severely injured, people often die before they can be treated. However, many injuries worsen over hours or even longer.
A bruise to the heart muscle (myocardial contusion) may disrupt the heart's normal, rhythmic beating, making heartbeats too fast, too slow, or irregular (arrhythmia).
A tear in the wall of the heart (ventricular rupture) often causes fatal bleeding before people can be taken to a hospital. However, bleeding from a small tear is sometimes contained by the membrane around the heart (pericardium) long enough for people to receive treatment. Such blood collected around the heart can interfere with the heart's ability to fill with blood (see Cardiac Tamponade).
Damage to a heart valve can cause heart failure (see Heart Failure).
Rarely, a tear in the membrane that separates two chambers of the heart (septal rupture) may occur. Such a tear may not cause symptoms until some time after a blunt injury. The person may then develop heart failure.
Commotio cordis is the sudden stopping of the heart (cardiac arrest) caused by a blow to the front of the chest. Typically, this blow involves a hard object that is moving fast (such as a baseball or a hockey puck). Thus, commotio cordis usually occurs during sports activities in young people. The exact reason for cardiac arrest is unclear, but commotio cordis does not result from an underlying heart disorder or from physical damage to the heart muscle. Some experts think that cardiac arrest occurs because the blow occurs at a critical moment during the cycle that produces each heartbeat. The blow then disrupts the electrical signals that the heart sends to keep the heart pumping continuously and regularly.
A blunt injury to the heart can cause various symptoms. Most people have pain and often bruising or other injuries around the breastbone or ribs. Some people have symptoms of heart failure, such as shortness of breath. People may go into shock. Their skin may be sweaty, cool, and bluish, and blood pressure may be dangerously low. Heart rhythms may be abnormal. People may feel that their heart is pounding, racing, or beating abnormally (palpitations).
If people might have a blunt heart injury, an ECG is usually done to check for abnormal heart rhythms. Sometimes doctors also check the blood for substances (serum markers) released by the damaged heart.
Echocardiography is done, sometimes in the emergency department. Echocardiography may show abnormalities in the way the heart's walls move (see Echocardiography and Other Ultrasound Procedures). It may also show blood or fluid around the heart, or rupture of a heart wall, or damage to a heart valve.
People with an abnormal heart rhythm are kept in the hospital for monitoring because the abnormal heart rhythm may suddenly become serious.
If a blunt injury to the heart causes other problems (such as heart failure or a damaged heart valve), people are admitted to the hospital, and the problem is treated.
People who collapse after a blunt blow to the chest must be evaluated immediately to see if they are in cardiac arrest (see Cardiac Arrest). If they are in cardiac arrest, cardiopulmonary resuscitation is started as soon as possible and an automated external defibrillator (AED—see Figure: Automated External Defibrillator: Jump-Starting the Heart) is used if available. About 35% of people who are treated with an AED survive.
Several measures may help prevent commotio cordis. They include teaching players ways to protect themselves (certain defensive strategies), using chest protectors and softer baseballs, and having AEDs and trained emergency medical personnel at youth sporting events.
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