8 May, 2024

Heart Attack basics

Introduction:
A heart attack (HA) occurs when a portion of the heart muscle is damaged due to an interruption in the blood supply to that part of the heart.

The basic structure of the human heart, including heart arteries, is explained here.

Like any other organ, the human heart needs a constant blood supply to stay alive and function properly. Blood carries the necessary nutrients and oxygen. Arteries are natural conduits that carry blood to specific organs. Arteries of the heart are called ‘coronary arteries’.

Over time, circulating fat (lipid) molecules deposit on the inner surface of the arteries, causing blockages or ‘plaques’. The likelihood of a person developing blockages depends on the circulating fat levels as well as that person’s predisposition. For example, for the same lipid levels in the blood, individuals with diabetes are more likely to develop blockages than non-diabetics.

Plaques are usually progressive. A minor plaque may take years or decades before it becomes severe enough to interrupt blood flow. Conversely, there are situations where the plaque ruptures, causing blood clot formation over the rupture site. If large enough, this blood clot can immediately occlude the artery, stopping the blood flow immediately. This event is often sudden and causes the quintessential ‘heart attack’.