Standard echocardiography
Echocardiographic examinations were performed using a high-quality
echocardiography machine (Vivid 7, GE, USA) by two cardiologists. Our
echocardiography machine was additionally calibrated for international
studies by an independent organization (certificate no: B14091148).
Measurements of LV and LA dimensions were made in accordance with the
most up to date European Society of Echocardiography recommendations
(16). LVEF was measured using the modified biplane Simpson’s rule. The
ratio between peak early (E) and late (A) diastolic LV filling
velocities and E wave deceleration time was determined by standard
Doppler imaging. The timing of mitral and aortic valve opening and
closing were defined by a pulsed-wave Doppler tracing of the mitral
inflow and LV outflow. Lateral wall and septal tissue Doppler parameters
(E′ and A′) were measured as well. E/E′ was calculated manually.
Particular attention was given to limit myocardial tissue and
extracardiac structures, providing sufficient reliable data to obtain a
gray-scale image.