Sudden Cardiac Arrest
Sudden cardiac arrest (SCA) is a sudden and unexpected loss of heart function, often due to abnormal heart rhythms, known as arrhythmias. It occurs when the heart's electrical system malfunctions, causing the heart to stop beating effectively.
Causes of Sudden Cardiac Arrest
The most common causes of SCA include:
- Ventricular fibrillation (V-fib): a type of irregular heartbeat that can lead to cardiac arrest
- Ventricular tachycardia (V-tach): a fast and abnormal heart rhythm that can degenerate into V-fib
- Myocardial infarction (heart attack): damage to the heart muscle due to a blockage of blood flow
- Cardiomyopathy: diseases of the heart muscle, such as hypertrophic cardiomyopathy or dilated cardiomyopathy
- Electrical abnormalities: conditions that affect the heart's electrical system, such as long QT syndrome or Wolff-Parkinson-White syndrome
Symptoms of Sudden Cardiac Arrest
The symptoms of SCA can be sudden and dramatic, including:
- Loss of consciousness or fainting
- No breathing or abnormal breathing
- No pulse or a very weak pulse
- Chest pain or discomfort
- Shortness of breath
Risk Factors for Sudden Cardiac Arrest
Certain factors can increase the risk of SCA, including:
- Age: SCA is more common in people over 45 years old
- Family history: a family history of heart disease or SCA
- High blood pressure: uncontrolled high blood pressure can increase the risk of SCA
- High cholesterol: high levels of low-density lipoprotein (LDL) cholesterol can increase the risk of SCA
- Smoking: smoking can damage the heart and increase the risk of SCA
- Obesity: being overweight or obese can increase the risk of SCA
- Physical inactivity: a sedentary lifestyle can increase the risk of SCA
Treatment for Sudden Cardiac Arrest
Treatment for SCA typically involves:
- CPR (cardiopulmonary resuscitation): to maintain blood circulation and breathing
- Defibrillation: using a defibrillator to restore a normal heart rhythm
- Medications: such as epinephrine or amiodarone, to help restore a normal heart rhythm
- Implantable cardioverter-defibrillators (ICDs): devices that can detect and correct abnormal heart rhythms
Prevention of Sudden Cardiac Arrest
To reduce the risk of SCA, it is essential to:
- Maintain a healthy lifestyle: including a balanced diet, regular exercise, and stress management
- Control underlying medical conditions: such as high blood pressure, high cholesterol, and diabetes
- Avoid smoking and limit alcohol consumption
- Get regular check-ups: with a healthcare provider to monitor heart health
Frequently Asked Questions (FAQs)
What is sudden cardiac arrest?
Sudden loss of heart function, often due to abnormal heart rhythms.
What causes sudden cardiac arrest?
Usually caused by underlying heart conditions, such as coronary artery disease or cardiomyopathy.
What are the symptoms of sudden cardiac arrest?
Typically, collapse, loss of consciousness, and absence of pulse or breathing.
How is sudden cardiac arrest diagnosed?
Diagnosed based on medical history, physical exam, and tests like ECG and echocardiogram.
Can sudden cardiac arrest be treated?
Yes, with prompt CPR and defibrillation, and possibly medication and hospitalization.
What is the role of CPR in treating sudden cardiac arrest?
Crucial to maintain blood circulation and increase chances of survival until medical help arrives.
How effective is defibrillation in treating sudden cardiac arrest?
Highly effective if done promptly, can restore normal heart rhythm and improve survival rates.
Can sudden cardiac arrest be prevented?
Possibly, by managing underlying conditions, maintaining a healthy lifestyle, and avoiding risk factors.
What are the risk factors for sudden cardiac arrest?
Include age, family history, high blood pressure, high cholesterol, smoking, and existing heart conditions.
What is the prognosis for someone who has had sudden cardiac arrest?
Generally, depends on promptness of treatment, underlying condition, and overall health, with variable survival rates.
Article last updated on: 18th October 2025.
If you have any feedback, please get in touch.
See more
Medical AI Assistant with Differentials, Guidance, Transcriptions, Notes, Medical Encyclopedia and Explainable AI.
Medical Disclaimer
The information provided is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read on this site. We we do not guarantee, and assume no legal liability or responsibility for the accuracy, currency, or completeness of the information provided.