Imaging adult patients with Fontan circulation

Abstract

Survival after the Fontan procedure for palliation of single ventricle congenital heart disease has improved. However, adults with Fontan circulation are at risk for several complications including heart failure, thromboembolism, and protein-losing enteropathy. This review discusses the role of noninvasive imaging for surveillance and early detection of anatomic and functional abnormalities of the Fontan circulation that can impact the risk for Fontan failure over time. Echocardiography is the first-line imaging modality for the adult Fontan patient. Use of established techniques, such as tissue Doppler imaging, and newer techniques, such as myocardial deformation and three-dimensional imaging, has improved the ability of echocardiography to serially assess ventricular and valvular function in this population. Strain imaging, in particular, is effective for early detection of subclinical ventricular dysfunction, is reproducible and can be incorporated into a routine clinical echocardiography protocol. Cardiac magnetic resonance (CMR) imaging complements echocardiography and overcomes the limitation of poor acoustic windows in adult patients, especially with regards to visualizing the cavopulmonary anastomoses and pulmonary arteries. High resolution imaging with CMR provides reliable assessment of ventricular size and function. Novel techniques utilizing CMR, such as computational fluid dynamics, have provided important insights into Fontan fluid dynamics, and the impact of Fontan geometry on flow efficiency through the circulation. Recent advances in echocardiography and CMR have improved detection of structural and functional abnormalities in adults with Fontan circulation and are essential in monitoring for complications in this growing population.