Transthoracic echocardiography:
Resting echocardiograms were recorded in the left lateral decubitus
position by the main investigator (ES) using the same digital ultrasound
scanner in all participants (Vivid E9, GE Vingmed Ultrasound, Horten,
Norway). We obtained 2D-greyscale, tissue Doppler, and color Doppler
images in parasternal and apical views according to
recommendations.25 Three to five consecutive loops
were obtained and saved in cine loop format, including 200 milliseconds
(ms) before and after all beats.
The main investigator (ES) performed all analysis offline (Echo PAC
version 203, GE Vingmed Ultrasound, Horten, Norway), blinded to the
patients’ other data.
Conventional parameters of left ventricular (LV) size were obtained,
calculated, and indexed to body surface area according to
recommendations.25 We obtained LA 2D acquisitions from
atria-focused apical views. LA volumes were calculated by the summation
of discs in apical four- and two-chamber views.25Atrial volumes were indexed to body surface areas, and an average from
three consecutive loops was computed.