Anomalous origin of left main coronary artery from pulmonary artery: Patient characteristics and imaging associations on multidetector computed tomography angiography

Aim To evaluate the various imaging features and associations on multidetector computed tomography (CT) angiography in patients with anomalous origin of left main coronary artery (LMCA) from pulmonary artery (ALCAPA). Materials and Methods We retrospectively reviewed multidetector CT angiography studies done for the evaluation of congenital heart diseases at our institution through 2014 to 2021. Cases with ALCAPA were identified and relevant history and imaging findings including the origin of coronary arteries, left ventricular (LV) morphology and functions, intercoronary collaterals, and associated abnormalities were evaluated. Results Twelve patients (eight males, three adults, and nine children; age range: 2 months to 54 years) with ALCAPA were included. Gradually progressive dyspnea and failure to thrive (6/9; 66.67% each) were the most common symptoms among children, whereas adults were commonly asymptomatic (2/3; 66.67%). The LMCA was originating from pulmonary sinus, main, and right pulmonary artery in 6 (50%), 5 (41.66%), and 1 (8.3%) patients, respectively. In adult-type ALCAPA, right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (LCx) were dilated and tortuous, with the presence of well-developed intercoronary collaterals and preserved LV ejection fractions; these features were not seen in patients of infantile ALCAPA. LV dysfunction with global hypokinesia was the most common wall motion abnormality (7/12; 58.33%). Conclusion Degree of collateralization could be the key factor determining the time of presentation, clinical symptoms, and LV function, thus influencing clinical outcomes. Patients with infantile ALCAPA present with features of heart failure and have dilated and dysfunctional LV consequent to lack of collaterals, unlike adult-type ALCAPA.