Heart Attack and Sudden Cardiac Arrest Differences

Heart Attack and Sudden Cardiac Arrest

Heart attack and sudden cardiac arrests are two terms often used interchangeably by people. Both heart attack and sudden cardiac arrest are life-threatening conditions, but they are not synonyms.

Heart attack and heart failure are two different problems with radically different causes and treatments. Understanding the difference helps in taking prompt action in case of sudden incidence.

This post establishes the difference between heart attack and cardiac arrest to save some valuable minutes.

What is a heart attack?

A heart attack happens when oxygen-rich blood doesn’t reach the heart due to blocked arteries. The heart works by the principle of double circulation.

In short, the heart pumps oxygen-rich blood to other parts of the body via an artery while the veins collect deoxygenated blood from the body parts to the heart.

From the heart, the deoxygenated blood reaches the lungs via the pulmonary artery where the blood gets oxygenated. Now, oxygenated blood reaches the heart via the pulmonary vein for circulation throughout the body.

The main reason behind the lack of blood supply to the heart is usually associated with blocked arteries. The blockage occurs as fat, cholesterol, or any other material builds up.

Build-up leads to the formation of plaque in the coronary arteries. When there is no supply of blood entering the heart, the muscles in the portion of the heart start to die.

A heart attack or myocardial infarction can be fatal, but treatment helps people to maintain the quality of their life.


The symptoms of a heart attack include:

  • Pressure, tightness, pain, or aching feeling in the chest and arms which may spread to the neck or back
  • Nausea
  • Indigestion
  • Heartburn
  • Abdominal pain
  • Shortness of breath
  • Cold sweat
  • Fatigue
  • Light-headedness or sudden dizziness

Not all will have heart attack symptoms and the same severity of the symptoms. Some people have mild or severe pain while others do not experience any symptoms.

What to do?

Even if you are sure it’s what condition it is, call emergency. Every minute counts with heart conditions. Once the emergency team arrives, they will take the patient to the hospital.

The emergency medical staff are trained to handle emergency cases and will start the emergency procedure on travel.


A heart attack happens when one or more coronary arteries get blocked. The build-up of cholesterol and other fatty deposit leads to the formation of plaque.

The plaque narrows the arteries or completely blocks the arteries and results in coronary artery disease. Coronary artery disease mostly causes s heart attack.

At the time of heart attack, the plaque ruptures and releases cholesterol and fatty deposits into the bloodstream. A blood clot forms at the site of plaque rupture.

If it’s a large clot, it blocks the blood flow through the artery and starves the heart of nutrients and oxygen. Early diagnosis helps prevention of further heart attacks.


In case of a blockage in the arteries, the doctor will recommend a procedure to eliminate the blockage and prevent the occurrence of another heart attack.

  • Angioplasty: the removal of plaque from a blocked artery using a balloon
  • Stent: placed within the artery to keep it open after angioplasty.
  • Heart bypass surgery: the doctor will bypass the blocked artery and reroute the blood surrounding the blockage. The average CABG cost in India lies somewhere around 293000 Rupees. 
  • Pacemaker: an electronic device implanted beneath heart skin to maintain a normal rhythm.
  • Heart transplant: this is the last resort in case of severe blockage.
  • Drugs: the doctor might prescribe aspirin, antiplatelet and anticoagulants, nitroglycerin, and painkillers to treat a heart attack.

What is sudden cardiac arrest?

Sudden cardiac arrest doesn’t have a contributing factor such as blocked arteries in a heart attack. Sudden cardiac arrest occurs when the heart abruptly loses its function.

Cardiac arrest results from a fault with the heart’s electric system, which disrupts the pumping action of the heart and halts blood flow.

Though sudden cardiac arrest is not the same as a heart attack, a heart attack can cause electrical disturbance and lead to cardiac arrest.

If not treated immediately, cardiac arrests can become fatal. Fast and appropriate medical care increases the chances of survival.

CPR (Cardiopulmonary resuscitation) using a defibrillator or chest compression enhances the chances of survival.


The symptoms of cardiac arrest are usually sudden

  • Chest discomfort
  • Shortness of breath
  • Weakness
  • Fast-beating
  • palpitations
  • Sudden collapse
  • No pulse
  • No breathing
  • Loss of consciousness


Arrhythmia is a common cause of sudden cardiac arrest. The electrical system of the heart controls the heart rate of heartbeat rhythm. A shift from the normal electrical system results in arrhythmia.

Minor arrhythmia doesn’t cause many problems, but a severe arrhythmia especially, in the left ventricle, poses serious problems. People with a pre-existing heart condition are known to develop arrhythmia.

The common heart conditions include:

  • Coronary artery disease
  • Heart attack
  • Enlarged heart or cardiomyopathy
  • Valvular heart disease
  • Congenital heart disease
  • Electrical Impulse Problems


CPR and defibrillation are the most common form of treatment used in case of emergency. The two treatments work within a few minutes of cardiac arrest and revive the heartbeat.

If a person survives cardiac arrest, the doctor will suggest one of the following treatments reduce the chance of another arrest.

  • Medication helps lower high pressure and cholesterol.
  • Surgery: treats blocked arteries damaged blood vessels.
  • Diet and exercise is the most important treatment. It strengthens the heart muscles and prevents further complications.

Bottom line

Heart attack and sudden cardiac arrest are not the same but, both are connected. A heart failure increases the chance of sudden cardiac arrest. Don’t delay in taking prompt action in both cases as minutes matter.