Cardiac arrest

Sudden cardiac arrest (SCA) is the sudden loss of all heart activity due to an irregular heart rhythm. Breathing stops. The person becomes unconscious. Without immediate treatment, sudden cardiac arrest can lead to death.

Emergency treatment for sudden cardiac arrest includes cardiopulmonary resuscitation (CPR) and shocks to the heart with a device called an automated external defibrillator (AED). Survival is possible with fast, appropriate medical care.

Sudden cardiac arrest isn't the same as a heart attack. A heart attack happens when blood flow to a part of the heart is blocked. Sudden cardiac arrest is not due to a blockage. However, a heart attack can cause a change in the heart's electrical activity that leads to sudden cardiac arrest.

Symptoms

Symptoms of sudden cardiac arrest are immediate and severe and include:

• Sudden collapse.
• No pulse.
• No breathing.
• Loss of consciousness.

Sometimes other symptoms occur before sudden cardiac arrest. These might include:

• Chest discomfort.
• Shortness of breath.
• Weakness.
• Fast-beating, fluttering or pounding heartbeat called palpitations.

But sudden cardiac arrest often occurs with no warning.

When to see a doctor

When the heart stops, the lack of oxygen-rich blood can quickly cause death or permanent brain damage.

• Chest pain or discomfort.
• Feeling of a pounding heartbeat.
• Rapid or irregular heartbeats.
• Unexplained wheezing.
• Shortness of breath.
• Fainting or near fainting.
• Lightheadedness or dizziness.