Sudden cardiac death (SCD), also called cardiac arrest, is an unexpected, sudden cardiac event that leads to death. SCD is more likely to occur in someone with an underlying cardiac abnormality. It is usually caused by an abnormal heart rhythm (arrhythmia) and is responsible for half of all heart disease deaths.
Use the links below to learn more about the causes, symptoms, treatment and more related to sudden cardiac death.
What causes SCD? The most common cause of cardiac arrest is
ventricular fibrillation (VF). The heart has a built-in electrical system. In ventricular fibrillation, the electrical signals that control the pumping of the heart suddenly become rapid and chaotic. The lower chambers of the heart, the ventricles, begin fibrillate rather than contract, so they can no longer pump blood from the heart to the rest of the body. Blood cannot flow to the brain, which becomes oxygen-starved. The person loses consciousness in seconds.
Patients with pulmonary hypertension are also at risk.
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Fainting during exercise
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Chest pain with exertion
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Shortness of breath
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Palpitations
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Syncope (fainting)
Unless an emergency shock is delivered to the heart to restore its regular rhythm, using a machine called a defibrillator, death can occur within minutes. More than more than 70% of ventricular fibrillation victims die before reaching the hospital.
How can SCD be prevented? To begin with, living a "heart healthy" life can help reduce the chances of cardiac arrest. This means getting regular exercise, eating healthfully, maintaining a healthy weight and not smoking. Treating and monitoring diseases and conditions that contribute to heart problems (such as high blood pressure, high cholesterol and diabetes) is also important.
For some patients, preventing sudden cardiac death means controlling or stopping the abnormal heart rhythms that may trigger ventricular fibrillation. This may be done through:
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Medications, including ACE inhibitors, beta blockers, calcium channel blockers and other antiarrhythmics
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