Influence of left ventricular relaxation on the pressure half time of aortic regurgitation

Abstract

Background-The severity of aortic regurgitation can be estimated using pressure half time (PHT) of the aortic regurgitation flow velocity, but the correlation between regurgitant fraction and PHT is weak. Aim-To test the hypothesis that the association between PHT and regurgitant fraction is substantially influenced by left ventricular relaxation. Methods-In 63 patients with aortic regurgitation, subdivided into a group without (n = 22) and a group with (n = 41) left ventricular hypertrophy, regurgitant fraction was calculated using the diVerence between right and left ventricular cardiac outputs. Left ventricular relaxation was assessed using the early to late diastolic Doppler tissue velocity ratio of the mitral annulus (E/ADTI), the E/A ratio of mitral inflow (E/AM), and the E deceleration time (E-DT). Left ventricular hypertrophy was assessed using the M mode derived left ventricular mass index. Results-The overall correlation between regurgitant fraction and PHT was weak (r = 0.36, p < 0.005). In patients without left ventricular hypertrophy, there was a significant correlation between regurgitant fraction and PHT (r = 0.62, p < 0.005), but not in patients with left ventricular hypertrophy. In patients with a left ventricular relaxation abnormality (defined as E/ADTI< 1, E/AM< age corrected lower limit, E-DT > 220 ms), no associations between regurgitant fraction and PHT were found, whereas in patients without left ventricular relaxation abnormalities, the regurgitant fraction to PHT relations were significant (normal E/AM: r = 0.57, p = 0.02; E-DT< 220 ms: r = 0.50, p < 0.001; E/ADTI < 1: r = 0.57, p = 0.02). Conclusions-Only normal left ventricular relaxation allows a significant decay of PHT with increasing aortic regurgitation severity. In abnormal relaxation, which is usually present in left ventricular hypertrophy, wide variation in prolonged backward left ventricular filling may cause dissociation between the regurgitant fraction and PHT. Thus the PHT method should only be used in the absence of left ventricular relaxation abnormalities. (Heart 1999;82:607-613) Keywords: aortic regurgitation; left ventricular relaxation; pressure half time Although severe aortic regurgitation should be corrected when more than mild symptoms develop, there is compelling evidence that patients with this condition should undergo valve replacement before the onset of permanent left ventricular damage, even in the absence of symptoms.1-3 The "55 rule" has been useful in gauging the timing of surgery in severe aortic regurgitation-that is, it ought to be performed before the ejection fraction falls below 55% or the end systolic left ventricular dimension exceeds 55 mm.1-3 The rule requires a correct classification of the severity of aortic regurgitation, a task which is now mainly performed using Doppler echocardiography. A standard method for the measurement of aortic regurgitation is the determination of the pulmonary to systemic cardiac output ratio. 5However, this is very time consuming and often not applica...

Aortic Stenosis with Other Concomitant Valvular Disease

“…The pressure halftime method is unreliable for the evaluation of AR in the presence of impaired LV relaxation. 41 Increased LV outflow tract velocities may prevent use of the simplified Bernoulli equation for calculation of the aortic valve pressure gradient. Invasive determination of the aortic valve area by the Gorlin formula is inherently inaccurate in patients with mixed aortic valve disease.…”

Distinct pressure half-time values by transthoracic echocardiography for grading of paravalvular regurgitation after transcatheter aortic valve replacement

“…PHT is known to be a parameter for AR quantification by TTE which is mainly influenced by elevated filling pressures in case of LVH 14 . In patients with aortic stenosis, LVH is common 25 .…”

“…This may be explained by the small number of patients in our study. Furthermore, elevated filling pressure reduces accuracy of PHT analysis in patients with AR 14 . In patients with LVH higher filling pressures have to be expected compared to patients without relevant LVH.…”

Expert consensus document on the assessment of the severity of aortic valve stenosis by echocardiography to provide diagnostic conclusiveness by standardized verifiable documentation

“…The green cir-cle is at the aortic annulus between the cusps. In normal AV PWD spectra of LVOT and AV are normally equal, because diameters are equal the presence of aortic and mitral regurgitations LV planimetry and volumetry results in total stroke volume (SV tot ) assessment, which is important for quantitative assessment of regurgitant fraction in concomitant valvular regurgitations in AS patients [61][62][63]. However, it should be emphasized that high flow conditions will overestimate LVSV by Doppler measurements in comparison to LV planimetry ( Fig.…”