Difference between heart attack and heart failure

[Naveed Yaseen]

The death of Michael Jackson following cardiac arrest prompted questions of the difference between that and a heart attack. It is important to understand a few facts about the heart.

Its job is to be a pump, pushing blood around the body. It does this by ‘beating’ — squeezing the blood out and pushing it on its way.

The heart beats constantly because it has its own special nerves that start an electrical impulse for every beat, making the heart squeeze.

The heart is made up of a unique type of muscle and has its own blood supply, providing the energy to beat constantly.

Also called a myocardial infarction, an MI or, to use more old-fashioned terms, a coronary, this is when the blood supply to the heart muscle suddenly goes wrong, starving it of oxygen and causing the muscle to die. This happens when one of the heart’s own blood vessels becomes blocked.

The severity of the heart attack depends on how big a blood vessel was blocked, and therefore how much heart muscle died.

What causes a heart attack?

Most commonly, a blood clot from a furred-up artery becomes stuck in one of the heart’s blood vessels and blocks it. This is most likely to happen if you are older, male, a smoker, overweight or have high cholesterol or high blood pressure.

What is heart failure?

Heart failure is quite a misleading term and would probably be better called ‘heart inefficiency’. It refers to the heart’s job as a pump. The heart squeezes a set amount of blood each time it beats.

If you have heart failure, the pump is less efficient and cannot cope with squeezing the same amount each time. It does not mean your heart is about to stop at any time — it means it isn’t working as well as it should.

What causes heart failure?

Many things affect the ability of the heart to function well as a pump, but commonly it follows a heart attack. Because some of the heart muscle dies after a heart attack, its power to squeeze out blood is reduced and heart failure develops.

Other common factors that can lead to heart failure are high blood pressure, alcohol and problems with the heart valves.

What is a cardiac arrest?

A cardiac arrest is the technical term for when the heart stops beating.

The special electrical impulses cease, so the heart no longer knows to beat. The electrical impulses can sometimes be restarted by defibrillating or ‘shocking’ the heart.

What causes a cardiac arrest?

Anything that leads to death, such as fatal injury or chronic disease. The list is endless, encompassing all causes of death.

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