Abstract 3420: Tricuspid E/Em: A Novel Tool for Evaluation of Pediatric Patients with Pulmonary Hypertension
Background: Hemodynamic data from cardiac catheterization have been used to assess patients with pulmonary hypertension. Noninvasive evaluation remains a challenge. Tissue Doppler Imaging (TDI), strain, and strain rate have shown promise as a noninvasive quantitative imaging modality. Mitral valve E/Em has been used to estimate left heart filling pressures. An analogous index has not been used to estimate right heart filling pressures. In pediatric patients with pulmonary hypertension, we compared hemodynamic data with a novel index of tricuspid E/Em utilizing Velocity Vector Imaging (VVI), software that generates TDI, strain, and strain rate.
Methods: Seventeen patients with pulmonary hypertension (age 3–18 years) and seventeen aged matched controls were compared retrospectively. Two-dimensional echocardiographic images in 4 chamber views were analyzed with VVI - to determine TDI, strain, and strain rate at the annular tricuspid, septal, and mitral valves. Mean right atrial pressure (MRAP), mean pulmonary artery pressure (MPAP), and pulmonary vascular resistance index (PVRI) from catheterization were compared with VVI measurements. E/Em was a ratio of pulse wave Doppler peak tricuspid early filling velocity (E) to TDI tricuspid early diastolic velocity (Em).
Results: Fourteen patients had primary pulmonary hypertension and three patients had pulmonary hypertension secondary to congenital heart disease. MRAP, MPAP, and PVRI were 7±6mmHg, 54±20mmHg, and 18±12WU respectively. Right ventricular dysfunction was observed as evidenced by abnormal tricuspid TDI peak systolic velocity, septal TDI peak systolic velocity, and tricuspid strain (all p<0.001). Diastolic dysfunction was observed based on lower tricuspid and septal annular early diastolic velocities (p≤0.01). Mean right atrial pressure correlated with tricuspid E/Em (r=0.74, p<0.001). Mitral TDI, strain, and strain rate were normal.
Conclusions: Tricuspid TDI generated by VVI combined with pulse wave Doppler (E/Em) predicts elevated right atrial pressure in pediatric patients with pulmonary hypertension. This novel index may be a useful tool in evaluating diastolic dysfunction especially in the longitudinal management of pulmonary hypertension.