CARDIOVASCULAR JOURNAL OF AFRICA • Volume 34, No 1, January–April 2023 10 AFRICA General Electric-Vingmed, Horten, Norway) using a 2.5-MHz phased-array cardiac probe with subjects in the left lateral recumbent position. An experienced sonographer acquired a complete 2D standard echocardiography, including apical four- and two-chamber LV views. All images were acquired at a frame rate of 50 to 70 frames/s for 2D views. Before each acquisition, images were optimised for endocardial visualisation. LV diameters were measured in time–motion mode or in 2D mode when the time–motion line was not perpendicular to the LV longitudinal axis. The left ventricle was considered severely dilated by TTE for a left ventricular end-diastolic diameter (LVEDDTTE) > 70 mm. LV volumes were calculated from apical four- and two-chamber views according to Simpson’s biplane method.9 AR severity was assessed by an integrated approach using four quantification methods: vena contracta width, PISA, diastolic flow reversal velocity in the descending aorta, and pression half-time (PHT). The vena contracta width was obtained from the parasternal long-axis view. A narrow colour sector scan coupled with the zoom mode was used to improve measurement accuracy. Using a Nyquist limit of 50–60 cm/s, a vena contracta width < 3 mm correlates with mild AR, whereas a width > 6 mm indicates severe AR. Depending on the orientation of the jet, PISA was measured in the apical five-chamber or parasternal long-axis view with the lower Nyquist limit set at 30 cm/s. Peak AR jet velocity and integral velocity time were determined using continuous-wave Doppler across the aortic valve. The PISA radius was measured from a stop frame as the distance between the regurgitant orifice and the first aliasing in early diastole (closest to the peak of regurgitant velocity) (Fig. 2). Grading of the severity of AR classified regurgitation as mild when EROA was < 10 mm² or RVol was < 30 ml, and moderate or severe when EROA was ≥ 30 mm² or RVol was ≥ 60 ml. End-diastolic velocity flow reversal in the descending aorta (EDVDA) was measured in the upper descending aorta at the aortic isthmus level using a suprasternal view with pulsed Doppler. The sample volume was placed at the origin of the left subclavican artery and it was aligned as much as possible along the major axis of the aorta. The Doppler filter was decreased to its lowest setting to allow detection of low velocities (< 10 cm/s). End-diastolic velocity measured at peak R wave exceeding 20 cm/s indicated severe AR.3 PHT was obtained from the AR flow curve obtained for an apical five-chamber view.3 A PHT of < 200 ms indicated severe AR, whereas a value of > 500 ms was in favour of mild AR. CMR imaging was performed on a 3T system (General Electric Signa HDxt) with an eight-phased-array cardiac coil, electrocardiogram triggered and breath-holding in expiration. After a series of scouting images to determine the position and orientation of the left ventricle within the thorax, Ciné Fiesta sequences for cardiac morphology and function were performed with a steady-state free precession technique in 10 to 15 parallel short-axis views. Each slice (slice thickness: 8 mm, gap: 0 mm) was obtained during one breath-hold of 10 to 15 seconds. CMR and TTE left ventricular ejection fractions (LVEF) were based on endocardial tracing of the LV chamber from the images on different axis views. On each image, end-diastole was defined as the frame in the cardiac cycle in which the cardiac volume was largest. End-systole was defined just before the opening of the mitral valve leaflet or the frame in the cardiac Five patients with AF Twelve patients with significant other valvular disease or cardiomyopathy TTE available within three months of CMR 229 patients with a main diagnosis of aortic regurgitation 198 patients 50 patients Fig. 1. Flow chart of the population. Fig. 2. Regurgitant volume by the PISA method.
RkJQdWJsaXNoZXIy NDIzNzc=