Background The anomalous origin of the left coronary artery (LCA) from the pulmonary artery (ALCAPA) and congenital left main coronary artery atresia (CLMCA-A) are two kinds of very rare coronary heart diseases which affect heart function profoundly.This study aimed to retrospectively illustrate the clinical features and therapy experience of ALCAPA and CLMCA-A patients.Methods From April 1984 to July 2012,in Beijing Anzhen Hospital,23 patients were diagnosed with ALCAPA and 4 patients with CLMCA-A.We summarized the clinical data of the 27 cases and retrospectively analyzed the clinical manifestation,diagnosis,and treatments of these two kinds of congenital coronary abnormalities.Results The 23 patients (13 males and 10 females,aged ranging from 2.5 months to 65 years) identified with ALCAPA were classified into infantile type (age of onset younger than 12 months,16 cases) and adult type (age of onset older than 12 months,7 cases).Four patients were diagnosed with CLMCA-A (three males and one female,aged ranging from 3 months to 2 years).The main clinical manifestations of infantile-type ALCAPA and CLMCA-A include repeated respiratory tract infection,heart failure,dyspnea,feeding intolerance,diaphoresis,and failure to thrive.And these two congenital coronary abnormalities might be misdiagnosed as endocardial fibroelastosis,dilated cardiomyopathy,and acute myocardial infarction.As for the adult-type ALCAPA,cardiac murmurs and discomfort of the precordial area are the most common presentations and might be misdiagnosed as coronary heart disease,myocarditis,or patent ductus arteriosus.In ECG examination:Infantile-type ALCAPA and CLMCA-A showed abnormal Q waves with T wave inversion in leads I,avL,and V4-V6,especially in lead avL.However,ECG of adult-type ALCAPA lacked distinct features.In chest radiography:pulmonary congestion and cardiomegaly were the most common findings in infantile-type ALCAPA and CLMCA-A,while pulmonary artery segment dilation was more common in adult type.In echocardiography,the common features of infantile-type ALCAPA and CLMCA-A included left ventricular enlargement,left ventricular systolic function normal or mildly reduced in CLMCA-A or significantly reduced in ALCAPA,and moderate to large mitral valve.It was performed in 9 of 23 cases of ALCAPA and showed the origin of the dilated right coronary artery (RCA) from the right sinus of the aortic root and absence of LCA origin in angiography.After opacification of RCA,reverse flow in the LCA and pulmonary artery was visualized through coronary artery collateral circulation.Angio was performed in three of the four cases of CLMCA-A and showed left main coronary artery was a blind end,with diameter of only 1.1-2.0 mm.Treatment and prognosis:21 patients with ALCAPA had cardiac surgery and 6 of them died postoperatively.Fifteen postoperative patients survived without overt symptoms within the follow-up period of 6-166 months (median 17 months).As for treatment of CLMCA-A,four patients took digoxin and diuretics without undergoing cardiac surgery.Their clinical symptoms improved during the close follow-ups.Conclusions ALCAPA and CLMCA-A are two rare coronary artery abnormalities that affect cardiac function in infants and children.In younger patients with cardiomegaly and heart dysfunction these two congenital coronary diseases should be noticed.