Abstract: Backgrounds Anomalous origin of a coronary artery from the opposite sinus of Valsalva (ACAOS) is a very rare coronary artery malformation. If it occurs during adolescence, it will cause very serious consequences, such as angina pectoris, myocardial infarction and even sudden cardiac death (SCD). The main imaging examination methods for the diagnosis of ACAOS include multi-detector row computed tomographic (MDCT) and coronary angiography (CAG). However, transthoracic echocardiography (TTE) has rarely been reported in the diagnosis of ACAOS.Objective To explore echocardiographic characters of adolescent ACAOS patients and announcements for scanning, and to improve the understanding for this disease, the detection rate and the diagnostic accuracy of TTE.DesignBy retrospectively analyzing the results of TTE in adolescent ACAOS patients diagnosed by multiple examination methods or surgery, the echocardiographic features and scanning points were summarized.Methods Between April 2016 and September 2019, 9 hospitalized patients with ACAOS were retrospectively reviewed at the Pediatric Cardiovascular Center, Beijing Anzhen Hospital. All patients were confirmed by multiple imagings and/or surgical procedures.Main Outcome MeasuresThe echocardiographic characters of ACAOS.Results Among 9 patients with ACAOS, 6 patients were ALCAOS and 3 patients were ARCAOS. All patients had related clinical symptoms after strenuous exercise, including chest congestion, chest pain, syncope and even sudden death. Seven patients underwent surgical operations and 2 patients underwent regular outpatient reexamination.The echocardiographic characters of ACAOS include a.The origin of ectopic coronary artery was slightly higher than the normal origin, and the origin of ectopic coronary artery could be clearly shown in the left high parasternal short axis view. b.The inlet and outlet of coronary artery was not consistent for intramural coronary artery. c.The wall of the aorta with intramural coronary artery was displayed as a "double-border". d.Color Doppler flow imaging could display the linear diastolic blood flow signals of the coronary artery and intramural coronary artery running between the aorta and the root of the pulmonary artery. e.Spectral Doppler could measure the velocity of abnormal blood flow in coronary artery and determine the time phase of abnormal blood flow.Conclusion TTE is the preferred imaging method for screening and diagnosis of ACAOS. In the diagnosis process, the clinical manifestations of patients should be closely combined, especially for adolescents who have chest congestion, chest pain, syncope and sudden death after exercise. TTE is crucial to improve the detection rate of this disease.

Key words: Anomalous origin of a coronary artery from the opposite sinus of Valsalva, Transthoracic echocardiography, Sudden cardiac death, Intramural coronary artery