Sudden cardiac arrest is the sudden, unexpected death due to loss of heart function, breathing and consciousness. It most frequently occurs in adults of mid-30 to mid 40’s and affects men more often than women.

Sudden cardiac arrest occurs due to electrical disturbance of the heart. The heart’s pumping action stops blood flow to the rest of the body and the oxygen rich blood is unable to reach the heart muscle. This in turn causes damage to the heart.  

Proper medical attention is crucial for individuals suffering from sudden cardiac arrest. If not treated immediately, sudden cardiac arrest can lead to death. Administering CPR (compressions to the chest) during an episode can help improve the chances of survival until medical personnel arrive.



Symptoms of sudden cardiac arrest include:

  • Sudden collapse
  • Loss of heart function/ No pulse
  • Loss of breathing
  • Loss of consciousness


Although sudden cardiac arrest occurs with no warning, a few cases in which a warning may present itself through symptoms leading to sudden cardiac arrest include: 

  • Dizziness
  • Fainting
  • Chest pain
  • Shortness of breath
  • Vomiting






Most sudden cardiac arrests are caused by abnormal heart rhythms called arrhythmias. They represent a problem with the heart’s electrical system, in which case the heart is unable to pump blood. The most common arrhythmia is called ventricular fibrillation, in which rapid, electrical impulses cause the ventricles to quiver uselessly instead of pumping blood.

The sinus node, a specialized group of cells located in the upper right chamber of the heart, act as a natural pacemaker for the heart and send electrical impulses in an order manner to help direct blood flow from the heart to the rest of the body and regulate heart rate levels. If disturbances occur within the sinus node, an arrhythmia can result. In such cases, the heart either beats too fast, too slow or at an irregular rate and can lead to a sudden stop in heart function (sudden cardiac arrest).

A few heart conditions that can lead to sudden cardiac arrest include:

  • Coronary artery disease: A condition in which the arteries become clogged with cholesterol and other deposits, decreasing blood flow to the heart.
  • Heart attack: A blockage of blood flow to the heart muscles.
  • Enlarged heart (cardiomyopathy): A type of heart disease in which the heart's muscular walls stretch and enlarge or thicken.
  • Valvular heart disease: A type of heart disease in which leaking or narrowing of the heart valves can lead to stretching or thickening of the heart muscle or both.
  • Congenital heart disease: A type of heart disease present at birth.
  • Electrical problems in the heart: Disturbances which cause heart rhythm abnormalities.


Risk factors

Factors that can increase the risk of sudden cardiac arrest include the following:

  • Being a smoker
  • Being male
  • Being of older age (45-55 years old)
  • Being overweight
  • Having high blood pressure or high cholesterol
  • Having diabetes
  • Having a family history of coronary artery disease
  • Having a family history of cardiac arrest
  • Having had a prior heart attack
  • Having nutritional imbalance
  • Using illegal drugs
  • Drinking alcohol excessively


Possible complications that can arise from sudden cardiac arrest include the following:

  • Reduced blood flow to the brain, which causes unconsciousness
  • Brain damage
  • Death



Sudden cardiac arrest requires immediate medical attention. A few standard treatment options vital to treating sudden cardiac arrests include:

  • Immediate cardiopulmonary resuscitation (CPR): a procedure that involves adding compressions to the chest to maintain a flow of oxygen rich blood to the body’s vital organs.


  • Defibrillation: A procedure that involves triggering electrical shocks through the chest wall to the heart in order to administer normal heart rhythm and keep it under control.


Depending on the cause of the cardiac arrest, a doctor may recommend the following treatment options to reduce the risk of another cardiac arrest:

  • Anti-arrhythmic drugs: Medications used to treat potential arrhythmia complications.


  • Cardioverter-defibrillator: A device which monitors heart rhythm and acts as a pacemaker to detect any abnormal rhythms. It sends out low to high energy shocks to trigger and reset the heart to a normal rhythm.


  • Coronary angioplasty: A surgical procedure which involves opening blocked coronary arteries and restoring blood flow to the heart, in order to reduce the risk of serious arrhythmia.


  • Coronary bypass surgery: A surgical procedure which  involves restoring blood flow to the heart muscle by redirecting blood flow around a section of a blocked artery in the heart.


  • Radiofrequency catheter ablation: A surgical procedure which involves sending radiofrequency energy along a pathway to create an electrical block and stop arrhythmia. 


  • Corrective heart surgery: A procedure that involves surgical repair of a faulty valve or diseased heart muscle tissue.
  • Heart transplantation: A surgical transplant procedure performed on individuals with end stage heart failure or severe coronary artery disease.




Although there is no sure way to know the risk of sudden cardiac arrest, a few preventive measures that can help reduce risk include:

  • Going for regular medical checkups and screening for heart disease
  • Quitting smoking
  • Drinking alcohol in moderation
  • Maintaining a healthy diet
  • Staying physically active
  • Taking proper medications for high cholesterol or diabetes
  • Being trained in CPR in cases of cardiac emergencies