Vasospastic angina temporally associated with intravaginal administration of misoprostol: a case report and diagnostic insights from hyperventilation and acetylcholine testing

We report the case of a 58-year-old woman who developed typical chest pain following intravaginal administration of misoprostol, used routinely as a premedication before a hysteroscopy. Misoprostol is a synthetic prostaglandin E1 analogue widely employed for cervical softening and the medical management of an incomplete abortion, and is generally considered safe. The chest pain was accompanied by transient, severe ST-segment elevation (up to 6 mm) in the inferior and inferolateral electrocardiogram (ECG) leads, which resolved promptly after sublingual nitrate administration. A hyperventilation test (5 minutes at 30 breaths per minute) demonstrated a paradoxical reduction in peak diastolic flow velocity in the mid-to-distal left anterior descending coronary artery. Invasive coronary angiography showed smooth, angiographically normal coronary arteries, but provocation with intracoronary acetylcholine induced complete vasospasm of the left circumflex artery. This case underscores the importance of recognizing vasospastic angina even in non-cardiology settings. It highlights the value of targeted noninvasive and invasive diagnostic testing to confirm this often overlooked, underdiagnosed, and undertreated condition.