Coronary angiography revealing a rare anomaly

Case Report

A 48-year-old man with a history of type 2 diabetes was referred to our outpatient clinic for preoperative evaluation before undergoing intrabdominal surgery. He reported recently aggravated chest discomfort at rest. The patient underwent a cardiac stress test, but the result was nondiagnostic. A left heart catheterization and coronary angiogram were performed (Figures).

What was identified?

Single coronary ostium originating from the right sinus of Valsalva.

Diagnosis:

Cardiac catheterization revealed that our patient had a single coronary ostium originating from the right sinus of Valsalva, from which the left anterior descending (LAD), circumflex, and right coronary arteries were originating (Figures). No significant stenosis was identified in any of the epicardial coronary arteries. The patient’s LAD artery followed an intraseptal course. His condition was considered relatively benign, and we decided to follow him as an outpatient.

Coronary artery anomalies are usually encountered on diagnostic coronary angiograms. The presence of a single coronary artery is very uncommon. This anomaly arises during coronary development, which begins in the third week of embryonic development. Coronary artery anomalies account for up to 1.3 % of anomalies identified on coronary angiograms.¹ Overall, the most common coronary anomaly is the separate origin of the circumflex and LAD arteries, accounting for 35.3% of cases. The second most common coronary anomaly is the right coronary artery originating from the left coronary sinus, occuring in 20.6% of cases. Certain coronary anomalies (eg, coronary artery fistulas, passage of the coronary artery between the aorta and pulmonary trunk, origin of the major coronary artery from the pulmonary trunk) are more likely to cause ischemia than benign anomalies, where the coronary arteries originate from the aorta, but in unusual locations.

A single coronary artery is far less common, and cases originating from the right sinus of Valsalva was reported to be 0.019% among 126,595 patients undergoing coronary angiography.¹ An anomalous left main coronary artery (LMCA) arising from the right coronary system can follow 1 of 4 courses: septal, anterior free wall, retroaortic, and interarterial. Unlike LMCAs, LAD arteries often follow 1 of the first 2 courses—septal or anterior free wall. Differentiation of these 2 courses in coronary angiography can be made using the “dot and eye” method.² In a 30º right anterior oblique view, before turning to the apex at the midseptum, the LAD will pass left and downward (forming the lower half of the “eye”) in a septal course, while it will pass left and upward (forming the upper half of the “eye”) in an anterior free wall course

.

In our patient’s case, the LAD artery follows the intraseptal course. This condition is relatively benign and not associated with sudden cardiac death, which is a concern for interarterial types. For that reason, we pursued observation of this patient without any surgical intervention. Our patient’s coronary anomaly should more properly be called a single coronary ostium because all coronaries are present.³ Although coronary angiography is the gold standard for diagnosing coronary artery disease, multislice computed tomography or magnetic resonance imaging of the heart is frequently required for further delineation of the coronary anatomy in such cases.