日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

We report a 19 year-old male with no symptoms who was diagnosed as a rare congenital coronary anomaly (CCA). He was previously diagnosed in our center as a small ventricular septal defect. Routine echocardiography indicated abnormal blood flow into the main pulmonary artery (PA), suggesting CCA. Electrocardiogram showed no ischemic changes.

The multi-slice cardiac computed tomography (MSCT) showed an anomalous vessel (AV) originating from the PA, and an anomalous right coronary artery originating from the left coronary sinus (ARCALCS) (Fig. 1

• Fig. 1 The multi-slice cardiac computed tomography showing ALADPA and ARCALCS

).

The AV was morphologically similar to the left anterior descending (LAD) artery, and was mildly enlarged and tortuous. It was located on the right side of the anterior interventricular sulcus (AIVS) and sprouted branches to supply the right ventricular wall. These were thought to be the right ventricular branches of the LAD.^1）

• 1) Cho JS, Kim J, Yoon SP: Dual left anterior interventricular coronary artery with rare course in a Korean. Anat Cell Biol 2015; 48: 144–146

The normal LAD (n-LAD) originating from the left main coronary artery (LMCA) was smaller than the AV. The n-LAD was located on the left side of the AV along the AIVS and terminated at the cardiac apex. Selective left coronary angiography showed that the blood flow of the AV was supplied by retrograde flow from collaterals of the n-LAD (Fig. 2

• Fig. 2 Left coronary angiography showing ALADPA supplied by collaterals from the n-LAD (red circle)

). These results confirmed that the AV was the anomalous LAD from the PA (ALADPA).

ARCALCS had the separated orifice close to the LMCA and passed the interarterial course. The segments and the branches of ARCALCS were normal for the right coronary artery.

ALADPA is an extremely rare CCA with a frequency of 0.0008%.^2）

• 2) Villa AD, Sammut E, Nair A, et al: Coronary artery anomalies overview: The normal and abnormal. World J Radiol 2016; 8: 537–555

This anomaly may be a cause of sudden cardiac death, ischemia and heart failure in adults.^3）

• 3) Ishmail MY, Nassar MI, Hamad MA: Anomalous left anterior descending coronary artery arising from pulmonary artery in a 63 year-old male patient: Case report and literature review. Heart Views 2015; 16: 98–103

Though our case currently has no symptoms because of the existence of the n-LAD, sufficient collaterals to ALADPA and no event of kinking of ARCALCS, he has a possibility of encountering ischemic events in the future. Thus, routine assessment of myocardial ischemia (e.g. exercise treadmill test or stress imaging) is necessary.

In our case, MSCT was useful for diagnosis.