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Sudden Cardiac Arrest (cont.)

Key Points

  • Sudden cardiac arrest (SCA) is a condition in which the heart suddenly and unexpectedly stops beating. When this happens, blood stops flowing to the brain and other vital organs.

  • Sudden cardiac arrest usually causes death if it's not treated within minutes.

  • Sudden cardiac arrest usually occurs when the heart develops an arrhythmia (irregular heartbeat) that causes the heart to stop pumping blood to the body.

  • Sudden cardiac arrest is not the same as a heart attack. During a heart attack, the heart usually doesn't stop beating. Sudden cardiac arrest, however, can happen after or during recovery from a heart attack.

  • Most cases of sudden cardiac arrest are due to an arrhythmia called ventricular fibrillation. Other electrical problems in the heart also can cause sudden cardiac arrest. Several factors can cause the electrical problems that lead to sudden cardiac arrest. These factors include coronary artery disease (CAD), severe physical stress, inherited disorders, and structural changes in the heart.

  • Sudden cardiac arrest occurs most often in people in their mid-thirties to mid-forties. It affects men twice as often as women. The major risk factor for sudden cardiac arrest is undiagnosed CAD.

  • Usually, the first sign of sudden cardiac arrest is loss of consciousness (fainting). At the same time, no heartbeat (or pulse) can be felt. Some people may have a racing heartbeat, dizziness, lightheadedness, chest pain, shortness of breath, nausea (feeling sick to the stomach), or vomiting before sudden cardiac arrest.

  • Sudden cardiac arrest often happens without warning. It requires immediate emergency treatment. Doctors rarely have a chance to diagnose sudden cardiac arrest with medical tests as its happening. Instead, sudden cardiac arrest usually is diagnosed after it happens. Doctors do this by ruling out other causes of a person's sudden collapse.

  • Sudden cardiac arrest requires immediate treatment with a defibrillator. This device sends an electric shock to the heart. The shock may restore a normal rhythm to a heart that's stopped beating. To work well, defibrillation much be done within minutes of sudden cardiac arrest.

  • Automated external defibrillators (AEDs) are special defibrillators that untrained bystanders can use. These devices are becoming more available in public places like airports, office buildings, and shopping centers.

  • If you survive sudden cardiac arrest, you usually will be admitted to a hospital for observation and treatment. Your medical team will try to find out what caused your sudden cardiac arrest. If you're diagnosed with CAD, you may have angioplasty or coronary artery bypass grafting. These procedures help restore blood flow through narrowed or blocked coronary arteries.

  • Often, people who have sudden cardiac arrest get a device called an implantable cardioverter defibrillator (ICD) to prevent a repeat sudden cardiac arrest. This small device is surgically placed under the skin in your chest or abdomen. An ICD uses electric pulses or shocks to help control dangerous arrhythmias.

  • Talk to your doctor about ways to prevent death due to sudden cardiac arrest. Medical devices, medicines, and lifestyle changes can lower your risk for sudden cardiac arrest. What steps you should take depend on if you've already had sudden cardiac arrest, if you've never had sudden cardiac arrest but are at high risk for the condition, or if you've never had sudden cardiac arrest and have no known risk factors for the condition.

SOURCE: National Heart Lung and Blood Institute; "What is Sudden Cardiac Arrest."

Last Editorial Review: 6/26/2009

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