Artida

Echocardiography was performed in a standard manner with the following commercially available echocardiographic machines: IE 33, EPIQ 7, EPIQ Elite (Philips Healthcare, Eindhoven, North Brabant, the Netherlands), Artida (Canon Medical Systems, Otawara, Tochigi, Japan), and ACUSON SC 2000 (SIEMENS Healthineers, Erlangen, Bavaria, Germany). TR severity was determined using the integrative, qualitative, and semiquantitative approaches, as recommended by the American Society of Echocardiography.¹⁰ TR severity was assessed according to the width of the vena contracta and jet area of regurgitation with systolic flow reversal in the hepatic veins. Because quantitative assessments were not available in this retrospective study, blinded TR regrading was performed by 2 experienced cardiologists (N.M and M.S.) in 30 randomly selected cases to ensure the reliability of the severity diagnosis. No patients were diagnosed with TR of moderate or less severity. In cases of massive TR with laminar flow, we did not measure TR pressure gradient (TRPG) from the jet velocity because it is less reliable for the estimation of pulmonary artery pressure. All echocardiographic examinations were performed by experienced sonographers and confirmed by licensed echocardiologists (T.K and T.O.).

All echocardiographic examinations were performed using commercially available equipment (iE33; Philips Medical Systems, Andover, Massachusetts, USA, and Artida; Canon Medical Systems, Otawara, Japan), which was maintained following the guidelines.¹⁴, ¹⁵ The left ventricular end‐diastolic diameter (LVDd), interventricular septum thickness, posterior wall thickness (PWTd), and left ventricular end‐systolic diameter (LVDs) were measured in parasternal long‐axis views. Left ventricular volumes and LVEF were measured using the disk summation method from apical 4‐ and 2‐chamber views. The relative wall thickness (RWT) was calculated as (2 × PWTd/LVDd). Devereux's formula was used to calculate left ventricular mass (LVM). The maximum left atrial volume (LAV) was measured from apical 4‐ and 2‐chamber views using the disk summation method. LVM and LAV were corrected for body surface area (LVMI: LVM index; LAVI: LAV index). LVEF was measured using Simpson's method. Furthermore, the tissue Doppler‐derived early diastolic mitral annular velocity (e′) was measured at the septal and lateral wall sites in the apical 4‐chamber view. The ratio of early diastolic mitral inflow velocity (E) to e′ (E/e′) was calculated as the mean of the septal and lateral E/e′. The peak tricuspid regurgitation velocity was derived from the peak tricuspid regurgitation jet velocity.