2.2 Standard Echocardiographic Examination
Transthoracic echocardiographic examinations were performed with S5-1
probe, 1-5MHz (CX50, Phillip, Netherlands). Two-dimensional (2D) and
Doppler echocardiography were performed according to the guidelines of
the American Society of Echocardiography5. The
following echocardiographic views were recorded over three cardiac
cycles: left parasternal long- and short axis views and apical two‐
apical three- and apical four‐chamber views. Images were recorded on
external hard disk and stored in digital format for offline analysis
(Q-lab 10.8.5). The right ventricular anteroposterior diameter and LV
diameter, left atrial (LA) diameter, LV interventricular septum (IVS)
and LV posterior wall (LVPW) thickness and aortic diameter were measured
at long axis view. The right atrial (RA) diameter was measured at apical
four-chamber view. The pulmonary diameter was measured at pulmonary long
axis view. LV systolic function included LV volumes, left ventricular
ejection fraction (LVEF) were measured by the modified biplane Simpson’s
rule. Mitral, aortic and pulmonary artery Doppler flow profiles were
recorded, including maximum mitral inflow velocity at early (E) and late
(A) diastole. Pulsed tissue Doppler imaging was obtained with the sample
volume placed at the septum of mitral valve and free wall of tricuspid
valve at the apical 4-chamber view. Velocity of mitral annulus at early
diastole (e’), late diastolic myocardial a’) velocities, and RV TDI-s
were recorded. The E/e’ ratio, being recorded at the level of the septum
of the mitral annulus, was used as an index of LV filling pressure.
Tricuspid annular plane systolic excursion (TAPSE) was measured in
apical four-chamber view via placing the cursor at the tricuspid
anterior annulus and measuring the distance of systolic annular RV
excursion along a longitudinal line. All images were collected by an
experienced investigator in echocardiography who was blinded to the
clinical information.