Echocardiographic Examination
Comprehensive transthoracic echocardiography was performed using Philips
IE 33 system (Philips Medical Systems, Bothell, WA, USA). Images were
stored and analyzed using Syngo software platform (Siemens Medical
Solutions, MI, US). Standard echocardiographic parameters of left atrial
volume; LV size and systolic and diastolic function; LVOT and aortic
valve (AV) gradients and AV area were measured by the primary reader
(AC) under the guidance of an experienced echocardiographer (JG)
according to the recommendations of American Society of Echocardiography
(ASE) guidelines13,14.
For left ventricular global longitudinal strain analysis (GLS), Tomtec
Cardiac Performance Analysis version 1.3.0.91 was used
(Unterschliessheim, Germany). The software detects lateral and septal
walls and divides each into three segments (basal, mid, and apical) to
calculate the strain via speckle tracing. An average strain for entire
LV in apical four chamber, apical two chamber, and apical three chamber
views were used to calculate the GLS. Strain measurement was accepted
after visual inspection and when the software demonstrated adequate
tracking. If tracking was suboptimal, the endocardial border was
manually retraced. Ten subjects were randomly selected to calculate the
interobserver variability between the measurements of two independent
investigators (AC, JG). Both investigators were blinded to each result.