2.3. Transthoracic Echocardiography

TTE was performed, in accordance with the current recommendations [15]. Echocardiographic exam included the evaluation of left ventricular (LV), end-diastolic (EDV), and end-systolic volumes (ESV). LV ejection fraction (LVEF) was assessed using the modified Simpson’s rule in the apical two- and four-chamber view. Once optimized, RV visualization by probe adjustment, tricuspid annular plane systolic excursion (TAPSE) was calculated by aligning an M-mode cursor parallel with the RV free wall and entangling the tricuspid annulus. Pulmonary artery systolic pressure (PASP) was obtained through the tricuspid regurgitant jet velocity, using systolic trans-tricuspid pressure gradient calculated by the modified Bernoulli equation and adding the value of right atrial pressure, derived from the inferior vena cava diameter and degree of respiratory collapse [16]. RV dysfunction was defined, in accordance with the current guidelines [15], and PH through echocardiographic assessment, according to European Society of Cardiology (ESC) guidelines [17]. TAPSE/PASP ratio was calculated as a non-invasive index of RV-arterial coupling.

Mitral (MR) and tricuspid regurgitation (TR) were assessed using by the color doppler method [16]. Only patients with adequate echocardiographic windows and good quality echocardiographic images were included in this study.