Cardiac Arrest v Heart Attack
The Difference Between A cardiac Arrest and a Heart Attack
20th November 2016, Updated 13th June 2020
A human heart is about the size of one's fist
This is what a real heart looks like - albeit a lamb's one. Your human heart is about the size of your fist!
You can clearly see the coronary arteries on top - those are the arteries that feed the heart itself. Those are the ones that, when blocked, cause a heart attack.
A heart attack (also called a myocardial infarction) occurs when part of the heart’s blood supply is reduced or blocked, causing the heart muscle beyond that point to die.
This video by Blausen Medical gives a great explanation:
A person having a heart attack is awake and may complain of a vice like squashing pain in the central chest. The pain may also radiate out into the arms, shoulders, neck, jaw and back. They might look a pale grey colour. Their pulse could be irregular, and they might feel short of breath, dizzy, nauseous, and have an impending sense of doom.
Sudden Cardiac Arrest
A sudden cardiac arrest (SCA) occurs when the heart has stopped. This could be caused by a heart attack, but it could also have other causes, like heart disease, drowning, electrocution, recreational drugs or other poisons and an issue with the heart's electrical system.
The Heart's Electrical System
A cardiac arrest is often due to an electrical problem.
The heart's electrical system is very complex, and it is possible for something to go wrong with that process.
The video below gives a very quick and simple overview of how the heart's electrical system works.
The heart of a person in cardiac arrest has stopped beating altogether, or stopped beating in an efficient, organised way. Blood is no longer pumped through the body and oxygen is no longer supplied to the brain and cells. The person becomes unconscious and lifeless, though may have agonal gasps or seizure-like activity.