Aortic Regurgitation: Quantitative Methods by Echocardiography

Abstract

Quantification of aortic regurgitation (AR) is a common and difficult clinical problem. The severity of regurgitation has traditionally been estimated with the use of contrast aortography, which is impractical as a screening tool or for serial examinations. In the past two decades, Doppler echocardiography has emerged as an important tool in the quantification of AR. Pulsed Doppler mapping of the depth of the regurgitant jet into the left ventricle was one of the initial echocardiographic methods used for this purpose. The slope and pressure (or velocity) half-time of continuous-wave Doppler profiles of regurgitant jets are also useful. These Doppler techniques may be used to determine the regurgitant volume or regurgitant fraction in patients with AR. The use of color Doppler to measure the height (or cross-sectional area) of the regurgitant jet relative to the height (cross-sectional area) of the left ventricular outflow tract is both sensitive and specific in the quantification of AR. More recently, the continuity principle has been used to determine the effective aortic regurgitant orifice area, which increases as AR becomes more severe. Although this is a promising tool, calculation of this value is not yet common practice in most echocardiography laboratories. Although no single echocardiographic technique is without limitations, all have some validity, and it is reasonable to use a combination of them to obtain a composite estimate of the severity of AR.

Evaluation of Aortic Valve Disorders Using Stress Echocardiography

“…Similarly, the ratio of regurgitant jet area to LVOT area can also be obtained from the parasternal short axis view with comparable accuracy and correlation with angiographic results (r = 0.91). Other methods to assess AI has been utilized, but techniques such as the pressure half time method can be altered by loading conditions, and the quantification of the regurgitant volume or fraction is impractical and time consuming 28 …”

Left Ventricular Strain as Predictor of Chronic Aortic Regurgitation

“…The grade of AR defined as Doppler parameters including visual estimated density (dense regurgitation flow on continuous Doppler), diastolic flow reversal in descending thoracic aorta (mid- to holo-diastolic) and jet deceleration time (pressure halt time less than 500 ms) and/or quantitative parameter including width of vena contracta (more than 0.3 cm), jet/left ventricular outflow tract width ratio (more than 45%) and regurgitation volume (more than 45 mL/beat). 2) 3) 4) Patients didn't satisfied one or more those criteria were excluded.…”

Long‐Term Outcome in Asymptomatic Patients with Severe Aortic Regurgitation, Normal Left Ventricular Ejection Fraction, and Severe Left Ventricular Dilatation

“…The presence of AR was diagnosed with color flow Doppler echocardiography. The assessment of AR severity was based on the first years on the proximal jet width or cross‐sectional area obtained from the long‐axis view immediately below the aortic valve (within 1 cm of the valve) and its ratio to the LV outflow tract diameter 8 and afterwards on an integrated approach using all the established criteria 9–12 . LV diameters were measured by 2D echocardiography‐guided M‐mode from the parasternal short‐axis view at the mitral chordae level 13 and indexed to body surface area.…”