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.