Echocardiography evaluation
mitral E-wave deceleration
DECUBITUS
Transthoracic Echocardiography (TTE) was performed using echocardiography equipment, Acuson SC2000TM ultrasound system (Acuson, Siemens, CA, USA), with a 4 MHz probe (Acuson 4V1c). The images were obtained while subjects were at rest and in the left lateral decubitus position. All images acquisition and measurement were performed according to the recommendations of the American Society of Echocardiography (ASE) guidelines.Standard 2D-TTE and strain imaging were performed at baseline and week 24 by an expert cardiologist who was blinded to the study protocol. Two-dimensional images were optimized to achieve the highest frame rate possible. Tissue Doppler Imaging (TDI) of the interventricular septum and lateral wall was recorded using the apical 4-chamber view with the narrowest sector angle feasible and a high frame rate. The images were digitally captured for subsequent analysis. LV systolic and diastolic function parameters including the global LV ejection fraction (LV EF) were assessed. LV EF was calculated by modified Simpson’s rule after measuring the end-diastolic volume (EDV) and the end-systolic volume (ESV), from both four-chamber and two-chamber views. LV diastolic function was assessed via pulsed-wave (PW) Doppler of the mitral inflow. Indices were measured by placing the pulsed-wave Doppler at the tip of the mitral valve leaflets during diastole, and mitral inflow velocities were recorded from the apical 4-chamber view (A4C). These included measurements of peak E-wave velocity (E), peak A-wave velocity (A), mitral E/A ratio, mitral E-wave deceleration time (DT), and isovolumic relaxation time (IVRT), which was recorded as the interval between aortic valve closure and mitral valve opening at a sweep speed of 100 mm/s. The Tissue Doppler Imaging (TDI)-driven mitral annular e’ velocity was measured as the average of septal and lateral e’ velocities. The E/e’ ratio was calculated as an index of LV filling pressure. We also measured LA volume at end of systole using Simpson rule. It was indexed for body surface area to drive LAVi. In addition, estimated pulmonary systolic pressure was determined.