Serial Assessment of Right Ventricular Deformation in Patients With Hypoplastic Left Heart Syndrome: A Cardiovascular Magnetic Resonance Feature Tracking Study

Background As right ventricular dysfunction is a major cause of adverse outcome in patients with hypoplastic left heart syndrome, the aim was to assess right ventricular function and deformation after Fontan completion by performing 2-dimensional cardiovascular magnetic resonance feature tracking in serial cardiovascular magnetic resonance studies. Methods and Results Cardiovascular magnetic resonance examinations of 108 patients with hypoplastic left heart syndrome (female: 31) were analyzed. Short-axis cine images were used for right ventricular volumetry. Two-dimensional cardiovascular magnetic resonance feature tracking was performed using long-axis and short-axis cine images to measure myocardial global longitudinal, circumferential, and radial strain. All patients had at least 2 cardiovascular magnetic resonance examinations after Fontan completion and 41 patients had 3 examinations. Global strain values and right ventricular ejection fraction decreased from the first to the third examination with a significant decline in global longitudinal strain from the first examination to the second examination (median, first, and third quartile: -18.8%, [-20.5;-16.5] versus -16.9%, [-19.3;-14.7]) and from the first to the third examination in 41 patients (-18.6%, [-20.9;-15.7] versus -15.8%, [-18.7;-12.6]; P-values <0.004). Right ventricular ejection fraction decreased significantly from the first to the third examination (55.4%, [49.8;59.3] versus 50.2%, [45.0;55.9]; P<0.002) and from the second to the third examination (53.8%, [47.2;58.7] versus 50.2%, [45.0;55.9]; P<0.0002). Conclusions Serial assessment of cardiovascular magnetic resonance studies in patients with hypoplastic left heart syndrome after Fontan completion demonstrates a significant reduction in global strain values and right ventricular ejection fraction at follow-up. The significant reduction in global longitudinal strain between the first 2 examinations with non-significant changes in right ventricular ejection fraction suggest that global longitudinal strain measured by 2-dimensional cardiovascular magnetic resonance feature tracking might be a superior technique for the detection of changes in myocardial function.