Fig. 3

a At our patient’s first visit (8-months old), color Doppler echocardiography showed a secundum defect with left-to-right shunt in the middle of atrial septum and the Qp/Qs ratio was 1.6 which meant the blood shunt was moderate (arrow). b On transthoracic echocardiography, we noted that the defect size of atrial septal defect was 8.1 mm (arrow). c When he was 3-years old, the left-to-right shunt still existed and the Qp/Qs ratio was 1.9 which meant the blood shunt was moderate to severe (arrow). d On transthoracic echocardiography, we noted that the existing defect had increased and the size was 10 mm (arrow), the blood shunt and defect size were all increased, which suggested exacerbation of atrial septal defect. LA left atrium, LV left ventricle, RA right atrium, RV right ventricle