ST Elevation Myocardial Infarction in a Rare Variant of Single Coronary Anomaly

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Authors

Bhalaghuru Chokkalingam Mani MD,
Novant Heart and Vascular Institute,
Matthews, NC 28105.

Alec Vishnevsky MD,
Assistant Professor of Medicine,
Department of Medicine,
Division of Cardiology,
Sidney Kimmel Medical College at Thomas Jefferson University
Thomas Jefferson University Hospital
Philadelphia, PA 19107

Ethan J Halpern MD
Professor of Medicine
Department of Radiology
Sidney Kimmel Medical College at Thomas Jefferson University
Philadelphia, PA 19107

David L.Fischman MD
Professor of Medicine
Department of Medicine
Sidney Kimmel Medical College at Thomas Jefferson University
Philadelphia, PA 19107

Case

A 53 year-old woman with a history of hypertension, dyslipidemia, diabetes, and tobacco use presented to the emergency room with the sudden onset of chest pain. An electrocardiogram (Figure 1) revealed an inferior ST elevation myocardial infarction and the patient was referred for emergent cardiac catheterization. An initial attempt to engage the left coronary artery was unsuccessful. Nonselective injection of the left coronary sinus failed to identify a coronary ostia (figure 2). Selective angiography of the right coronary artery (RCA) revealed a single coronary trunk that gave rise to separate origins of the major coronary arteries. The left circumflex artery (LCx) reached the left atrioventricular groove by coursing anterior to the pulmonary artery. The left anterior descending artery (LAD) courses posterior to the right ventricular outflow tract (RVOT) and then intraseptally to emerge in the anterior interventricular groove. An acute RV marginal branch also wraps anterior to the pulmonary artery and then courses toward the cardiac apex parallel to the LAD just to the right of the interventricular groove. The right coronary artery was occluded beyond the origin of these vessels (figures 3,4) and was successfully stented (figure 5,6). Multislice coronary computed tomography angiography confirmed the anatomical variant and the course of the vessels (figures 7,8).

Comments

Single coronary arteries are among the rarest of coronary artery anomalies with a reported incidence of 0.06-0.024%.1 Classification schemes have been developed based on the vessel course and their relationship to the great vessels. 2,3 Our patient’s anatomy is a Yamanaka R-III C (R-III combined) variant wherein the left coronary arteries have separate ostia arising

from the RCA and have a combination of courses including an anterior and intraseptal course. ST elevation myocardial infarction in this setting is extremely rare.4 Interventional cardiologists should be aware of such scenarios in order to accurately identify the coronary anatomy and provide timely treatment.