A 34-year-old woman who smokes heavily presents with episodes of chest pain occurring at rest during sleep. ECG during pain shows transient ST segment elevation, and angiography reveals no fixed obstructive lesion. What is the underlying mechanism?

• A Fixed atherosclerotic plaque limiting flow reserve
• B Coronary vasospasm ✓
• C Rupture of unstable plaque with nonocclusive thrombus
• D Microvascular dysfunction from diabetes

Explanation

Variant (Prinzmetal) angina results from episodic coronary artery vasospasm near an atherosclerotic plaque or even in angiographically normal vessels, producing transient transmural ischemia with ST elevation. Unstable plaque rupture underlies typical unstable angina and NSTEMI, where ST changes are depression or T wave inversion rather than transient elevation, and fixed stenosis produces exertional angina.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.