heart attack
Meaning of heart attack: The muscle of the heart starves while the person is usually awake and talking, which is what separates it from a cardiac arrest.
Definition of heart attack
A heart attack is the death of part of the heart muscle after the artery supplying it becomes blocked. The blockage usually forms when a fatty deposit in the artery wall cracks open and a clot builds on the tear. Muscle downstream is cut off from oxygen and begins to die, and the damaged area does not grow back.
What blocks the artery?
Fatty deposits build up inside the artery wall over years, a process called atherosclerosis. Most of the time a deposit narrows the channel gradually and the heart copes. A heart attack begins when the surface over a deposit cracks. Blood meets material it was never meant to touch, treats the crack as a wound and forms a clot on it, and that clot can seal the artery within minutes. This is why an attack often strikes someone who had no warning at all: the deposit that ruptures need not be the largest one, and coronary artery disease can be advanced without ever limiting exertion.
What does it feel like?
Most often heavy pressure, tightness or squeezing in the center of the chest, lasting more than a few minutes and not relieved by resting. The sensation may travel to the jaw, neck, shoulder, back or either arm. Sweating, nausea, breathlessness, lightheadedness and a sense of dread commonly go with it. Sharpness, or pain that changes with breathing or with pressing on the chest wall, points away from the heart. Presentations with no chest pain at all are well recognized, particularly in older adults, in women and in people with diabetes, where breathlessness or sudden exhaustion may be the only sign.
How is it different from cardiac arrest?
| Event | What is wrong | How the person appears |
|---|---|---|
| Heart attack | A blocked artery starves heart muscle | Usually awake, in discomfort, breathing |
| Cardiac arrest | The heart stops pumping altogether | Collapsed, unresponsive, not breathing normally |
| Angina | A temporary shortfall in supply, with no muscle death | Discomfort on exertion that settles with rest |
The two are linked but not the same. A heart attack can trigger cardiac arrest and is the commonest reason a previously well adult arrests, yet most heart attacks do not stop the heart. Time governs the outcome either way. Muscle deprived of blood dies progressively rather than all at once, so the extent of permanent damage tracks how long the artery stays shut.
How is it confirmed?
By two things together. An EKG records the electrical activity of the heart and can show the pattern of an artery blocked outright. A blood test measures troponin, a protein released when heart muscle is injured, and a level rising over a few hours points to damage happening now rather than in the past.
Also known as
Used in a sentence
The heart attack was confirmed by electrocardiogram changes and a rising troponin level.
Good to know
Chest pain is not a requirement, and breathlessness, sweating, nausea or discomfort in the jaw, back or arm can be the leading feature, with painless presentations recognized more often in older adults, in women and in people with diabetes.