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How does coronary heart disease lead to cardiac arrest or ventricular fibrillation?

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The role of coronary artery disease in heart attack — cardiovascular disease This micrograph shows a cross section of a coronary artery narrowed by an atherosclerotic plaque (purplish matter inside the artery). Most heart attacks are caused by the rupture of an atherosclerotic plaque, which triggers the formation of a clot that abruptly blocks blood flow to part of the heart muscle.

Coronary heart disease leads to cardiac arrest and ventricular fibrillation primarily by restricting the supply of oxygen-rich blood to the heart muscle, a condition often caused by atherosclerosis.2

When the heart muscle experiences extreme oxygen deprivation, it can trigger a breakdown in the heart's electrical control system. This disruption often manifests as ventricular fibrillation, where the lower chambers of the heart (the ventricles) quiver in an uncoordinated, chaotic manner rather than contracting effectively. Because this state prevents the heart from pumping blood to the brain and other vital organs, it results in total mechanical inadequacy and sudden cardiac arrest.1234

While this process is frequently associated with myocardial infarction, it can occur even in individuals without a history of heart attacks, as the underlying coronary artery disease may cause fatal electrical instability before other symptoms are recognized.34