Anomalous origin and interarterial course of the right coronary artery: diagnostic and therapeutic dilemmas.

746 origin of the RCA from the left sinus of Valsalva is an extremely rare anomaly found in approximately 0.019% to 0.49% of patients undergoing coronary angiography.1 An abnormal RCA origin may be either a benign and asymptomatic finding or a high-risk anatomical feature. Patients with the abnormal RCA origin may have a slit-like orifice and intramural or interarterial course (between the aorta and pulmonary artery).2 The artery may be compressed, and acute ischemia may occur.1,3 Moreover, an acute take-off angle and compression of the intramural segment narrowing the orifice may cause flow limitation. For this reason, such anatomic variants are considered potentially malignant. However, not all cases of the abnormal RCA origin have clinical implications because sudden cardiac death is rare in asymptomatic patients with this anomaly. A 41-year-old woman with a history of arterial hypertension, hypercholesterolemia, positive family history, and atypical chest pain was referred for an exercise stress test. It was clinically negative, but electrocardiography was positive. The results of an echocardiographic examination were normal. To exclude coronary artery disease, multislice computed tomography of the coronary arteries was performed (Figure 1A–C). The scan revealed an anomalous origin of the right coronary artery (RCA) from the left sinus of Valsalva. The initial 5-mm part of the artery was found to course intramurally in the wall of the aorta, and critical ostial stenosis was suspected (Figure 1A–C). Therefore, conventional coronary angiography was performed. It confirmed coronary anomaly and demonstrated a borderline (50%–60%) stenosis at the ostium of the RCA (Figure 1D). An