Coronary Vasospasm in a Patient With Argininosuccinic Aciduria

A 39-year-old male was referred for treatment of hypertension. He had been treated for argininosuccinic aciduria since 8 months of age. Therapeutic drugs, including L-arginine, sodium phenylbutyrate, and antiepileptic drugs, had been prescribed. A detailed medical history revealed that he complained of chest discomfort under psychologic stress. A 12 -lead electrocardiogram showed abnormal q waves in lead III and aVF. Transthoracic echocardiography showed hypokinesia of the left ventricular posterior wall. The patient was diagnosed with myocardial infarction because of coronary vasospastic angina by intracoronary acetylcholine provocation test. Argininosuccinic aciduria is a genetic disor-der of the urea cycle caused by a deficiency of argininosuccinate lyase. Reduction of the enzymatic activity leads to a decrease in nitric oxide production, even if arginine is supple-mented. Our case report supports the significance of endothelial function in the pathogen-esis of coronary vasospasm. (c) 2023 Elsevier Inc. All rights reserved. (Am J Cardiol 2023;192:155-159)