Echocardiographic assessment
We performed a complete conventional transthoracic echocardiogram with
subjects in left lateral decubitus using a Siemens Acuson SC 2000
(Mountain View, California-USA) echocardiographic equipment with a
phased array transducer. The right ventricular end-diastolic diameter
was measured in the apical four-chamber view, below the tricuspid valve.
The RV wall thickness was measured by 2D echocardiography in the
subcostal four-chamber view. Right atrial (RA) volume was obtained using
a single-plane method of disks in the apical four-chamber view at
ventricular end-systole, and it was indexed by body surface area. The
measurements of right ventricular fractional area change (RVFAC),
tricuspid annular plane systolic excursion (TAPSE), tricuspid S-wave
velocity, Tei index, E, A-wave velocities (rapid filling and atrial
contribution, respectively), E/A ratio, and tricuspid E/e’ ratio were
obtained according to the guidelines of the American Society of
Echocardiography and the European Association of Echocardiography
(5,10,11).