What actually happens inside the body during a heart attack?
An estimated 22 to 64 percent of heart attacks are silent, and a heart attack can feel like heartburn or, in women, like unusual tiredness.
▶ Start the storyA heart attack happens when blood flow decreases or stops in one of the arteries of the heart, so that part of the heart muscle is starved of oxygen and begins to die. Doctors call it a , and it is not the same as , when the heart stops pumping, although it can lead to one. This lesson describes what is known; it is not medical advice.
The usual cause is the story of a plaque. Most heart attacks are due to disease, and the usual mechanism is a complete blockage of a coronary artery caused by the rupture of a fatty plaque. A plaque can become unstable and rupture, and that promotes a blood clot that blocks the artery. This can occur in minutes, even though the plaque itself may have been present for decades without causing any symptoms.
Without blood, the muscle downstream suffers fast. Tissue begins to die within 15 to 30 minutes of loss of blood supply, and heart cells that die do not grow back: a collagen scar forms in their place. That is why a heart attack requires immediate medical attention, and why treatment aims to preserve as much heart muscle as possible. In one type, called a STEMI, treatments try to restore blood flow, either by pushing the artery open and sometimes leaving a small , or by using medicines to remove the blockage.
Step 1: Plaque ruptures
In a
Step 2: A clot blocks the artery
This can occur in minutes
Step 3: Oxygen runs out
Tissue begins to die within 15–30 minutes
Step 4: A scar forms
Dead heart cells do not grow back
Heart attacks do not always look like the movies. The most common symptom is chest pain or discomfort that classically spreads to the left shoulder, arm or jaw, and it can occasionally feel like heartburn. Women more often have no chest pain and instead have neck pain, arm pain or tiredness. And silent heart attacks with no symptoms at all are estimated to make up between 22 and 64 percent of all of them, found later on an ECG, with blood tests, or at autopsy.
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Recap
A heart attack is a blocked coronary artery starving part of the heart muscle, and the muscle that dies does not grow back.
💡 A trick to remember it · Picture a garden hose pinched shut: the lawn past the kink dies, and no amount of waiting grows it back.
Surprising fact · Between 22 and 64 percent of heart attacks are estimated to be silent.
Sources (1)
No source, no claim. Every fact in this lesson (17 claims) cites at least one of these.