Echocardiographic Assessments and Outcome Measurements
Patients underwent transthoracic echocardiography using a Siemens ACUSON SC2000 by an expert specialist of echocardiography. Measurements were in accordance with the latest guideline of The American Society of Echocardiography and the European Association of Cardiovascular Imaging9. All routine echocardiographic parameters in MS patients were measured and calculated using standard parasternal and apical windows. The planimetric method was utilized to measure MVA. Additionally, RV size was evaluated by conventional apical four-chamber view at end-diastole. RV systolic function was assessed by tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), peak systolic velocity of the tricuspid annulus (S’) using TDI, and RV free wall strain (RVFWS) by VVI software Syngo® Workplace. RV longitudinal function was evaluated by TAPSE in M-mode echocardiography with the cursor optimally aligned along the direction of the lateral annulus of tricuspid valve in the apical four-chamber cardiac view. TDI was employed to calculate S’, while taking caution to prevent velocity underestimation by keeping the annulus and the basal segment aligned with the Doppler cursor. FAC was assessed in RV-focused apical four-chamber view, by determining the end-diastolic and end-systolic area (100 × [End-diastolic area – End-systolic area] / End-diastolic area). Recorded offline images were analyzed by Syngo® Workplace software in order to measure strain. To guarantee that the entire myocardial wall was included, endocardial and epicardial borders of RV were traced and adjusted manually. The software automatically traced and calculated the velocity of the tangential motion of the speckles of the myocardium. RV free wall (RVFW) was defined as apical lateral, mid lateral, and basal lateral segments; and RV free wall strain (RVFWS) values were recorded and reported for each patient. (Figure 1.)