A single atrial septal defect masquerading as multiple defects due to a refraction artifact – A cautionary note

Echocardiography is useful for making a diagnosis of atrial septal defect (ASD) by directly visualizing the shunt flow. Herein, we present a case in which a single ostium secundum type ASD masqueraded as multiple defects on color flow imaging by transthoracic echocardiography. We confirmed by transesophageal echocardiography that this patient actually had a single ASD. An echocardiographic refraction artifact was considered to be the cause of this phenomenon. We need to be aware of the existence of this artifact to avoid misdiagnosis. 〈Learning objective: Echocardiography is useful for making a diagnosis of atrial septal defect (ASD). We present the case with a single ostium secundum type ASD which masqueraded as multiple defects on color flow imaging due to a refraction artifact. Refraction artifacts can make multiple false flow signals on color imaging. This case emphasizes the importance of an understanding of the existence of this artifact in not only B mode imaging but also color Doppler imaging.〉