Exertional Angina in a Child With Single Right Coronary Artery and Septal Course of the Left Anterior Descending Artery　― A Rare Cause of Angina ―

A 9-year-old girl complained of exertional chest pain. Computed tomography and catheter angiography showed that a single right coronary artery (RCA) originated from the right sinus of Valsalva and a slightly hypoplastic left anterior descending artery (LAD) branched from the RCA and ran between the ascending aorta and outflow tract of the right ventricle (Figure A–C). The left circumferential artery, which branched from the RCA and passed behind the ascending aorta, was extremely hypoplastic; the RCA supplied most of the posterolateral wall. During exercise stress myocardial perfusion imaging (thallium-201), she presented with chest pain at Bruce stage 5 and a small perfusion defect in the anterior wall was visible (Figure D,E; Supplementary Figures 1,2).

Figure.

(A,B) Coronary angiograms: frontal (A) and lateral views (B). (C) Curved view of computed tomography. The left anterior descending artery exhibits a septal course. (D,E) Thallium-201 myocardial perfusion imaging. Images during exercise stress (D) and rest (E).

Discussion

A single coronary artery is a rare congenital malformation with a prevalence of approximately 0.03%. Patients with a left main coronary artery arising from the RCA and coursing between the ascending aorta and main pulmonary artery are considered to be at high risk of sudden cardiac death (SCD), whereas an interventricular course of the LAD is considered benign.^1,2 However, this malformation can cause exertional chest pain, especially during childhood with a high exercise tolerance and daily exercise. Notably, in the present case, the ischemic area was limited due to the LCA hypoplasia being compensated by the large RCA; thus, the risk of SCD may be attenuated. Exercise restriction and β-blockers are considered beneficial for relieving the symptoms.

Supplementary Files

Please find supplementary file(s);

http://dx.doi.org/10.1253/circj.CJ-20-0383

References

• 1.   Vijayvergiya R, Kumar Jaswal R. Anomalous left anterior descending, absent circumflex and unusual dominant course of right coronary artery: A case report. Int J Cardiol 2005; 102: 147–148.
• 2.   Namboodiri N, Harikrishnan S, Tharakan JA. Single coronary artery from right aortic sinus with septal course of left anterior descending artery and left circumflex artery as continuation of right coronary artery: A hitherto unreported coronary anomaly. J Invasive Cardiol 2007; 19: E102–E103.