Figure 1: Echocardiographic Grading of Paravalvular Regurgitation. Panel A: Measurement of pressure half-time of aortic regurgitation off 5-chamber apical view. Panel B: Measurement of circumferential extent of aortic annulus and regurgitation in short axis view. Panel C: Measurement of velocity-time integral across the left ventricular outflow tract used to calculate left ventricular stroke volume. Panel D: Measurement of velocity-time integral across right ventricular outflow tract used to calculate right ventricular stroke volume.