Coronary Vasospasm While Treating Supraventricular Tachycardia: Is Adenosine Really to Blame?

Coronary artery spasm has been reported during adenosine stress testing. Herein, we describe a transient ST-segment elevation following adenosine therapy for supraventricular tachycardia. A 38-year-old male presented to the emergency department with palpitations. Electrocardiogram showed supraventricular tachycardia with short RP interval. Vagal maneuvers were unsuccessful. Adenosine was then administered in two successive injections of 6 and 12？mg dosages, respectively. A subsequent 12-lead electrocardiogram revealed ST-segment elevation in inferior leads with reciprocal changes. Coronary angiography disclosed nonobstructive coronary disease. A postprocedure electrocardiogram exhibited normal sinus rhythm with nonspecific T wave abnormalities. Cardiac biomarkers were elevated with a peak troponin I of 0.32. Echocardiogram depicted bicuspid aortic valve and normal systolic function. Electrophysiological study revealed a concealed left accessory pathway and successful radiofrequency ablation was performed. Given the dynamic changes in the electrocardiogram, we hypothesize that this event was most likely a coronary vasospasm. The mechanism of coronary spasm following adenosine injection remains uncertain. Potential mediators include channels and adenosine-2 receptors. 1. Introduction Adenosine is a frequently used pharmacologic stress agent in myocardial perfusion imaging and supraventricular tachyarrhythmia (SVT) termination, also known as atrioventricular blocking effect. Its safety profile is well established, and most of its side effects are mild and transient [1]. Coronary vasospasm has been reported during or after adenosine stress test, which may lead to seriously adverse outcomes [1]. Herein, we present a case of ST-segment elevation myocardial infarction following an intravenous bolus dose of adenosine for SVT termination. 2. Case Presentation A 38-year-old Hispanic male, without known cardiovascular diseases presented to the emergency room complaining of two-day history of intermittent palpitations. He also stated having a three-hour pressure-like epigastric discomfort with radiation to the right upper quadrant. The pain started while lifting heavy objects at work and continued intermittently. There was no history of syncopal or presyncopal episodes. His past medical history disclosed multiple episodes of palpitations since the age of 20, but no associated chest pain, a syncopal episode related to exercise a year earlier and negative history of illicit drugs, tobacco, or alcohol intake. Importantly, his father died at the age of 57 due to a