Sudden Cardiac Arrest

Sudden Cardiac Arrest

Fact Checked

Sudden cardiac arrest (SCA) is when the heart stops beating abruptly. When the heart stops beating, no blood and oxygen is delivered to the rest of the body. The heart has an internal pacemaker (a so called internal electrical system) that controls heart rhythm. When there is a malfunction in the electrical activity, it leads to arrhythmia. Arrhythmia is described as abnormal, irregular or loss of rhythm, particularly any abnormality in the rate, regularity or site of impulse origin or sequence of activation.  Sudden cardiac arrest happens when the heart develops arrhythmia causing it to stop beating.

Sudden cardiac arrest should not be confused with heart attack. In the cases of heart attack, the heart continues to beat despite a blockage in the coronary arteries. A heart attack may lead to sudden cardiac arrest and eventually, sudden cardiac death, if not given immediate and proper treatment.

Causes of Sudden Cardiac Arrest

As previously mentioned, sudden cardiac arrest is most often caused by arrhythmias. Occasionally, there is no known cause for SCA. Other possible causes of SCA include:

  • Ventricular fibrillation (type of arrhythmia) – electrical signals controlling the lower chambers of the heart become disorganized
  • Coronary heart disease
  • Cardiomyopathy (enlarged heart)
  • Valvular heart disease
  • Heart disease
  • Physical stress
  • Genetic disorders, such as congenital heart disease

Signs and Symptoms of Cardiac Arrest

The patient who is suffering from sudden cardiac arrest is unresponsive. SCA can be reversible if treated immediately. Recognition of signs and symptoms are important to be able to call for emergency assistance. Signs and symptoms of SCA include:

  • Sudden collapse
  • Absence of pulse
  • No breathing
  • Sudden loss of consciousness

Often, SCA occurs without warning, but at times, there may be signs and symptoms that can precede SCA. The following are:

  • Chest pain
  • Palpitations
  • Shortness of breath
  • Dizziness
  • Fatigue
  • Weakness
  • Syncope (fainting)
  • Blackout

First Aid Treatment for Sudden Cardiac Arrest

A person suffering from sudden cardiac arrest and not given immediate and proper medical care may die within a few minutes. Permanent brain damage is observed if it does not receive oxygen for six minutes. In cases of SCA, the earlier the treatment, the lesser the damage to the organs of the body, and the higher the survival rate. When a person suffers from SCA, it is important to administer first aid while waiting for paramedics.

Proper way to check for breathing of a patient suffering from sudden cardiac arrest
Proper way to check for breathing of a patient suffering from sudden cardiac arrest
  • Try to elicit a response from the patient by speaking loudly and clearly. Gently shake the shoulders of the patient.
  • If there is no response, place one hand on the patient’s forehead and using the other hand, place the fingers on the chin to tilt the head back. Place the ear near the patient’s mouth to listen and feel for breathing. Watch the chest for rise and fall. If there is no breathing, immediately call the local emergency number and begin CPR.
  • If one is trained to use automated external defibrillators (AED), which are usually accessible in various public areas, use this to correct the abnormal heart rhythm and restart the heart. If the AED is not available, do not stop with the CPR.

Sudden cardiac arrest is when the heart stops beating abruptly. In SCA, the patient has no pulse, is unconscious and is not breathing. Immediate medical attention is required.

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