All you need to know about cardiac arrest and how it differs from heart attack

Tamil Nadu Chief Minister J Jayalalithaa suffered a cardiac arrest in Apollo Hospital on Sunday evening where she was admitted over two months ago. Her condition is said to be critical after the cardiac arrest.

Here's the difference between heart attack and cardiac arrest:

Heart attack

* A heart attack is preceded by symptoms which occur hours, days or even weeks 

* It's caused due to blocked artery which sends blood to the heart.

* The blocked artery prevents blood from reaching a section of the heart causing the attack.

* The heart does not usually stop functioning after the attack.

* Heart attack can cause permanent damage to the heart.

* A heart attack could lead to a cardiac arrest.

Cardiac arrest

* Occurs suddenly and without any warning.

* It is caused due to electrical malfunction which leads to irregular heartbeat (arrhythmia).

* Pumping of blood from the heart to the entire body stops.

* The heart stops functioning following a cardiac arrest.

* Person loses consciousness and dies within minutes if they don't receive treatment.

* Heart attack and cardiac arrest are both life threatening and need immediate treatment.