RIGHT VENTRICULAR MYOCARDIAL STIFFNESS AND RELAXATION COMPONENTS BY KINEMATIC MODEL-BASED TRANSTRICUSPID FLOW ANALYSIS IN CHILDREN AND ADOLESCENTS WITH PULMONARY ARTERIAL HYPERTENSION

摘要

We hypothesized that the kinematic model-based parameters obtained from the transtricuspid E-wave would be useful for evaluating the right ventricular diastolic property in pediatric pulmonary arterial hypertension (PAH) patients. The model was parametrized by stiffness/elastic recoil k, relaxation/damping c and load x. These parameters were determined as the solution of m.d(2)x/dt(2 )+ c.dx/dt + kx= 0, which is based on the theory that the E-wave contour is determined by the interplay of stiffness/restoring force, damping/relaxation force and load. The PAH group had a significantly higher k and c compared with the control group (182.5 +/- 72.4 g/s vs. 135.7 +/- 49.5 g/s(2), p = 0.0232, and 21.9 +/- 6.5 g/s vs. 10.6 +/- 5.2 g/s, p <0.0001, respectively). These results indicate that in the PAH group, the right ventricle had higher stiffness/elastic recoil and inferior cross-bridge relaxation. The present findings indicate the feasibility and utility of using kinematic model parameters to assess right ventricular diastolic function. (C) 2019 World Federation for Ultrasound in Medicine & Biology. All rights reserved.