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What can happen when a coronary artery becomes blocked?

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Illustration of a human heart cross-section showing four chambers-left and right atria and ventricles-with labeled major blood vessels. An inset highlights cardiac muscle tissue, showing myocytes and intercalated disks. — human cardiovascular system The human heart is both a pump and a muscle. Its four chambers move blood efficiently, while cardiac muscle cells joined by intercalated disks synchronize each contraction.

When a coronary artery becomes blocked—a condition known as coronary occlusion—it restricts the supply of oxygen-rich blood to the heart muscle, leading to several serious health consequences.1234

Angina Pectoris: If the oxygen deprivation is insufficient to cause permanent tissue death, it often results in angina pectoris, which is characterized by chest pain or discomfort.23
Myocardial Infarction: If the blockage is severe or prolonged, it causes the death of a segment of heart muscle, known as a myocardial infarction or heart attack. This is often accompanied by severe, crushing chest pain, difficulty breathing, and other systemic symptoms.124
Severe Complications: Extreme oxygen depletion can lead to cardiac arrest, heart failure, or ventricular fibrillation, an uncoordinated contraction of the heart's lower chambers that can induce sudden death. Additionally, the damage may cause structural issues, such as the rupture of the heart's valves or walls.341

These conditions are primarily caused by atherosclerosis, where fatty plaques narrow or obstruct the arterial channel.523