Case-based approach to demonstrate utility of cardiac magnetic resonance imaging (MRI) for planning biventricular repair with inconclusive echo: illustration of two cases

Congenital heart defects that present earlier in life and involving a hypoplastic ventricle are sometimes channeled towards single-ventricle repair because of anatomical or logistic challenges (1). With the single-ventricular repair, the final result is the shunting of venous return directly into the pulmonary artery and the utilization of the functioning ventricle for systemic circulation (2). Though singleventricular repair has remarkable short-term results, long-term survivors experience declines in exercise tolerance, heart failure, arrhythmias, and thromboembolic complications (3). Given long-term functional and survival advantages of a two-ventricle circulation, exploring feasibility of biventricular repair is essential for improving prognosis. However, a successful biventricular repair requires sufficiently functioning ventricles to sustain a balanced flow through the pulmonary and systemic circuit. To evaluate the functional adequacy of the ventricle with hypoplasia, echocardiogram is conventionally used.