Echocardiogram protocol analysis.
The closest TTE study to the first medical visit in the Heart Valve Clinic was used as baseline analysis. TTE was performed using the commercially available echo systems in the Imaging Unit, according to the standard protocol (7,8). Measurements were reviewed and reperformed by trained echocardiographers.
The severity of AR was assessed using an integrated method including a combination of several measurements (vena contracta width, pressure half-time of the AR jet, the presence of diastolic retrograde flow in aorta, and the LV size) according to the established practice guidelines (9). Aortic regurgitation was considered significant by the presence of the following criteria: the width of the vena contracta > 6mm, pressure half-time < 200ms, the presence of diastolic retrograde flow in aorta and some degree of LV enlargement.
LV size was evaluated by its diameters from the parasternal long axis view and by its volumes from the apical four chamber view. LVEF was measured using Teicholz method and apical biplane Simpson´s method.
LV diastolic function was evaluated following the established recommendations from the American Society of Echocardiography and the European Association of Cardiovascular Imaging (10), that included the following parameters:
Transmitral flow was recorded by pulsed wave Doppler echocardiography, from apical four chamber view, by placing the sample volume at the tips of the mitral leaflets. Peak E wave velocity, peak A wave velocity, E to A wave ratio (E/A) and E wave deceleration time were determined.
Tissue Doppler imaging was performed in the apical four chamber view and pulsed wave Doppler sample volume was place in the septal and lateral mitral annulus. The peak annular systolic wave velocities were recorded (e’ septal and e’ lateral). From these measurements, the mitral E/e’ septal and E/e’ lateral ratios were calculated, as well as the mean of both results (E/e’ ratio).
The severity of tricuspid regurgitation (TR) was assessed using an integrated method, according to the established practice guidelines (9). The systolic pulmonary artery pressure (SPAP) was estimated using TR peak velocity and right atrial pressure, which was estimated by the inferior vena cava diameter from long-axis subxiphoid view and its response to inspiration.
LA size was measured at its antero-posterior diameter from the long axis parasternal view in the end-systolic period, and by LA volume, that was measured using the biplane area length method.
In a subgroup of patients with TTE performed in the Philips stations, LA auto-strain analysis was performed with an offline workstation (autostrain TOMTEC). From the apical four chamber view focus in the LA with a minimum loop length of 2 beats; the software uses Advanced Automatic View Recognition technology to identify LA and automatic contour placement, which automatically detects and places the LA border. The software automatically provides the measurement of the average strain for the three major LA function throughout the cardiac cycle: reservoir (LASr), conduit (LAScd) and contractile (LASct) values. The reference point for deformation analysis was at end diastole (Figure 1).