CT imaging features of atrioventricular shunts: what the radiologist must know

In the last decade, cardiac computed tomography (CT) has gained mainstream acceptance for the noninvasive exclusion of significant coronary disease in a selected population. Improvements in electrocardiogram (ECG)-triggered imaging techniques also allow, by extension, a proper evaluation of the complete heart anatomy. Given the increasing worldwide clinical implementation of cardiac CT for coronary artery evaluation, radiologists can, incidentally, be confronted with unfamiliar and previously unsuspected non-coronary cardiac pathologies, including congenital morphological defects. This presence of congenital heart disease (CHD) should not be overlooked, being the most common form of birth defect, with a total birth prevalence of 9.1 per 1000 live births worldwide [ 1 ]. The prevalence of adult patients with CHD is estimated to be 3000 per million adults [ 2 ]. Ventricular septal defects (VSDs) are the most frequent subtypes of CHD, accounting together with atrial septal defects (ASDs) for nearly half of all CHD cases [ 1 ]. While some small defects are rarely symptomatic and can go undetected for life, others are clinically significant and require adequate and timely medical intervention. In this article, we present the CT imaging features of atrioventricular (AV) shunts, highlighting both their embryological origins and associated relevant clinical features. Teaching points • Congenital heart disease (CHD) is the most common birth defect. • Ventricular and atrial septal defects account for nearly half of CHD cases. • Atrioventricular defects can frequently be detected on a cardiac CT. • Radiologists must be able to identify clinically significant atrioventricular defects.