Accelerated Idioventricular Rhythm at the Termination of an Episode of Vasospastic Angina.

A 57-year-old male with gastroesophageal reflux disease and esophageal stricture with dilation presented as a cardiac catheterization lab activation for anterolateral ST-segment elevation myocardial infarction. He had suffered an unwitnessed syncopal episode after severe substernal chest pain. Electrocardiogram (ECG) showed anterolateral ST-segment elevation. Markers of myocardial injury were negative. He subsequently had an unremarkable coronary angiogram, echocardiogram, and cardiac magnetic resonance imaging (MRI). He had another episode of crushing chest pain and palpitations during his hospital stay, which correlated with ST-segment elevation, followed by a slow run of ventricular arrhythmia that terminated after a dose of sublingual nitroglycerin. A diagnosis of accelerated idioventricular rhythm (AIVR) following coronary artery vasospasm (CAV) was made. This clinical vignette presents a unique presentation of AIVR following an episode of Prinzmetal's angina.