Atrioventricular Block Induced by Right Coronary Artery Spasm in Vasospastic Angina

BACKGROUND: Vasospastic angina (VSA) is a reversible cause of myocardial ischemia due to transient coronary spasm and may rarely be associated with conduction disturbances. CASE SUMMARY: A 64-year-old man presented with nocturnal rest angina. The initial angiography results were normal. Holter monitoring during symptoms showed transient ST-segment elevation with Mobitz type I second-degree atrioventricular (AV) block progressing to 2:1 AV block, causing presyncope. He later experienced syncope. Repeat angiography revealed diffuse coronary vasospasm involving the right coronary artery, fully reversible with nitrates, confirming VSA. Verapamil therapy resulted in symptom resolution and no further conduction abnormalities during follow-up. DISCUSSION: Right coronary artery spasm may induce transient AV block due to ischemia of the AV node. TAKE-HOME MESSAGES: VSA should be considered in unexplained AV block or syncope with ischemic electrocardiographic changes. Calcium-channel blockers are effective even in ischemia-induced conduction disorders.