Abstract
A 5-year-old boy with a precordial murmur was initially diagnosed with anomalous systemic arterial (ASA) supply to the left lung lower lobe combined with arterial-pulmonary venous fistula (APVF) by transthoracic echocardiography (TTE), then evaluated by computed tomography angiography (CTA) and digital subtraction angiography (DSA). He received interventional therapy and recovered well. Although ASA supply to the lung lobes combined with APVF is usually diagnosed by CTA, it may also be first diagnosed by TTE in a patient who has a significant heart murmur. Careful TTE examination can improve the diagnostic rate of this cardiovascular abnormality.