Regional Ventricular and Global Atrial Strain Characteristics in Patients with Hypoplastic Left Heart Syndrome and Right Ventricular Dysfunction: An Echocardiography, Cardiac MRI, and Invasive Hemodynamics Study.

Right ventricular (RV) systolic dysfunction is a risk factor for morbidity and mortality in children with hypoplastic left heart syndrome (HLHS). RV and right atrial (RA) strain evaluation by cardiac magnetic resonance (CMR) and transthoracic echocardiography (TTE) is feasible but knowledge of their adaptative changes to systemic pressure and association to invasive hemodynamics and adverse clinical outcomes (ACO) remains limited. We aimed to compare regional RV and RA strain in HLHS patients with and without abnormal RV ejection fraction (aRVEF) and assess strain relationship to invasive hemodynamics and ACO. CMR, TTE and cardiac catheterization data for 45 children with HLHS post-stage 2 palliation was retrospectively analyzed. RV and RA strain was assessed with speckle-tracking (TTE) and feature-tracking (CMR). Patients with aRVEF had higher indexed RV end-diastolic (p = 0.019) and end-systolic volumes (p = 0.0005), lower mass/volume ratio (p = 0.029), abnormal apical strain by CMR (longitudinal p = 0.026, circumferential p = 0.001, radial p = 0.0005) and TTE (p = 0.003), and higher global longitudinal to global radial strain ratio (p = 0.0005). RA reservoir strain (RASr) was significantly lower in aRVEF patients (CMR p = 0.009, TTE p = 0.018) and was associated with a composite of ACO (HR 0.81, p = 0.0021). There was no association between RA strain and catheterization data. RV maladaptation and systolic dysfunction in HLHS patients is characterized by increased volumes, decreased mass/volume ratio, and global and regional strain abnormalities, particularly decreased radial motion relative to longitudinal shortening and apical dysfunction. RA compliance decreases with aRVEF and is associated with ACO but not with invasive hemodynamics.