Anomalous Right Coronary Artery: A Case of Exertional Angina and Sinus Node Ischemia.

BACKGROUND

Anomalous right coronary artery (RCA) from the left coronary sinus is uncommon; chronotropic limitation from sinoatrial (SA) nodal ischemia is rarely recognized.

CASE SUMMARY: A 35-year-old athlete had exertional chest pain and shortness of breath. Computed tomography coronary angiography showed a left-dominant system and a nondominant anomalous RCA from the left cusp with acute takeoff, probable intramural course, and supply to the SA nodal branch. Dobutamine stress echocardiography reproduced the pain, without wall motion abnormalities but with blunted heart-rate response. After heart team discussion, right internal mammary artery-to-RCA bypass was performed. At 4 months, he was asymptomatic with restored chronotropic response.

DISCUSSION: In nondominant anomalous RCA, ischemia testing may be nondiagnostic; recognizing SA nodal supply can explain chronotropic insufficiency and guide intervention.

TAKE-HOME MESSAGES: Nondominant anomalous RCA may present with angina and chronotropic limitation. SA nodal ischemia can be an ischemic equivalent when regional wall motion abnormalities are absent.