Echocardiography:
1- Two-dimensional and Doppler Echocardiography
All echocardiographic studies were performed using a Vivid 9 machine
(GE Vingmed Ultrasound AS, Horten, Norway), equipped with a 3.5 MHz
transducer. A total of 3 cardiac cycles were recorded at the end of
expiration. Frame rate was set in the range 60-80 frames per second for
2-D image acquisition. Settings were adjusted manually to obtain optimal
images. All data were transferred to a workstation for further offline
analysis (EchoPAC PC; GE Vingmed Ultrasound AS).
Maximal wall thickness was measured from all LV segments from base to
apex in parasternal short axis view. Left ventricular end-systolic
diameter (ESD) and end-diastolic diameter (EDD) were measured from
parasternal long axis view according to recommendations of American
Society of Echocardiography (ASE) 14. Left ventricular
end-systolic volume (ESV), end-diastolic volume (EDV) and EF were
determined from the apical four and two-chamber views using Simpson’s
modified biplane method. Atrial diameter was calculated by M-mode or 2-D
echocardiography in the parasternal long axis plane. Left atrial (LA)
volume was obtained using the biplane area length method from apical
four and two- chamber images at end-systole and it was also indexed to
body surface area (BSA) as recommended 15.