stable angina

Stable angina is the heart's reliable warning light. It comes on with a familiar amount of effort — climbing the same hill, hurrying for a bus — and switches off when you stop and rest. Because it is so predictable, many people learn exactly how far they can go before it appears.

It is caused by a fixed coronary narrowing that allows enough blood flow at rest but cannot increase supply when the heart works harder. The resulting ischemia is felt as a pressing, squeezing or heavy discomfort in the chest, often spreading to the arm, neck or jaw, and lasting a few minutes. Rest or a nitrate spray, which dilates vessels and reduces the heart's workload, typically relieves it within minutes.

The defining feature is its stability: the pattern of triggers and duration has not changed recently. A clear change — pain at rest, with less effort, or lasting longer — suggests the angina is no longer stable and may herald an acute coronary syndrome, which is a medical emergency.

Stable angina reflects demand-driven ischemia, in contrast to the supply-driven, plaque-rupture mechanism of acute syndromes. It is usually managed with risk-factor control, anti-anginal drugs and, in selected cases, revascularization.