Impact of energy loss coefficient on left ventricular mass regression in patients undergoing aortic valve replacement: preliminary observation.
ABSTRACT The purpose of this study was to evaluate the impact of Doppler-derived energy loss coefficient (ELCo) on the regression of left ventricular (LV) hypertrophy after aortic valve replacement (AVR) in patients with severe aortic stenosis.
Twenty-four patients with severe aortic stenosis who underwent AVR with Carpentier-Edwards pericardial bioprosthetic valves (valve size 19 mm, n = 16; valve size 21 mm, n = 8) were examined. Within 12 months after AVR, follow-up echocardiography and Doppler measurements were performed. The effect of AVR was quantified on the basis of absolute and relative LV mass regression.
There were significant correlations between indexed ELCo and absolute (r = 0.50, P = .013) and relative (r = 0.48, P = .018) LV mass regression. The mean value of relative LV mass regression was 25%, and a cutoff value of 0.9 cm2/m2 for indexed ELCo could detect patients with relative LV mass regression > 25% after AVR with sensitivity of 71% and specificity of 100%.
ELCo, which can be calculated noninvasively from echocardiography, might be an important value to relate to LV mass regression in patients after AVR.
- SourceAvailable from: Jean Dumesnil[show abstract] [hide abstract]
ABSTRACT: We sought to obtain more coherent evaluations of aortic stenosis severity. The valve effective orifice area (EOA) is routinely used to assess aortic stenosis severity. However, there are often discrepancies between measurements of EOA by Doppler echocardiography (EOA(Dop)) and those by a catheter (EOA(cath)). We hypothesized that these discrepancies might be due to the influence of pressure recovery. The relationship between EOA(cath) and EOA(Dop) was studied as follows: 1) in an in vitro model measuring the effects of different flow rates and aortic diameters on two fixed stenoses and seven bioprostheses; 2) in an animal model of supravalvular aortic stenosis (14 pigs); and 3) based on catheterization data from 37 patients studied by Schöbel et al. Pooling of in vitro, animal, and patient data showed a good correlation (r = 0.97) between EOA(cath) (range 0.3 to 2.3 cm(2)) and EOA(Dop) (range 0.2 to 1.7 cm(2)), but EOA(cath) systematically overestimated EOA(Dop) (24 +/- 17% [mean +/- SD]). However, when the energy loss coefficient (ELCo) was calculated from EOA(Dop) and aortic cross-sectional area (A(A)) to account for pressure recovery, a similar correlation (r = 0.97) with EOA(cath) was observed, but the previously noted overestimation was no longer present. Discrepancies between EOA(cath) and EOA(Dop) are largely due to the pressure recovery phenomenon and can be reconciled by calculating ELCo from the echocardiogram. Thus, ELCo and EOA(cath) are equivalent indexes representing the net energy loss due to stenosis and probably are the most appropriate for quantifying aortic stenosis severity.Journal of the American College of Cardiology 03/2003; 41(3):435-42. · 14.09 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: To determine the accuracy of echocardiographic left ventricular (LV) dimension and mass measurements for detection and quantification of LV hypertrophy, results of blindly read antemortem echocardiograms were compared with LV mass measurements made at necropsy in 55 patients. LV mass was calculated using M-mode LV measurements by Penn and American Society of Echocardiography (ASE) conventions and cube function and volume correction formulas in 52 patients. Penn-cube LV mass correlated closely with necropsy LV mass (r = 0.92, p less than 0.001) and overestimated it by only 6%; sensitivity in 18 patients with LV hypertrophy (necropsy LV mass more than 215 g) was 100% (18 of 18 patients) and specificity was 86% (29 of 34 patients). ASE-cube LV mass correlated similarly to necropsy LV mass (r = 0.90, p less than 0.001), but systematically overestimated it (by a mean of 25%); the overestimation could be corrected by the equation: LV mass = 0.80 (ASE-cube LV mass) + 0.6 g. Use of ASE measurements in the volume correction formula systematically underestimated necropsy LV mass (by a mean of 30%). In a subset of 9 patients, 3 of whom had technically inadequate M-mode echocardiograms, 2-dimensional echocardiographic (echo) LV mass by 2 methods was also significantly related to necropsy LV mass (r = 0.68, p less than 0.05 and r = 0.82, p less than 0.01). Among other indexes of LV anatomy, only measurement of myocardial cross-sectional area was acceptably accurate for quantitation of LV mass (r = 0.80, p less than 0.001) or diagnosis of LV hypertrophy (sensitivity = 72%, specificity = 94%).(ABSTRACT TRUNCATED AT 250 WORDS)The American Journal of Cardiology 03/1986; 57(6):450-8. · 3.21 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: To determine the effect of systemic arterial hypertension on the indices of aortic stenosis (AS) severity. A severe supravalvar AS was created in 24 pigs. The maximum and mean pressure gradients across the stenosis were measured by Doppler echocardiography and by catheterisation. Both echocardiography and catheter data were used to calculate stenosis effective orifice area, energy loss coefficient, and peak systolic left ventricular wall stress. Measurements were taken both at normal aortic pressures and during hypertension induced by banding of the distal thoracic aorta in 14 pigs and by intravenous administration of phenylephrine in 10 pigs. During hypertension, systemic arterial resistance downstream from the stenosis increased greatly (all animals: 71 (40)%), whereas total systemic arterial compliance decreased significantly (-38 (21)%). Hypertension resulted in a moderate increase in effective orifice area (29 (14)%) and energy loss coefficient (25 (17)%) and substantial decreases in catheter gradients (maximum: -40 (20)%; mean: -43 (20)%; peak to peak: -70 (23)%) and Doppler gradients (maximum: -35 (17)%; mean: -37 (16)%). In multivariate analysis, peak to peak gradient was significantly (p < 0.001) related to the energy loss coefficient, mean flow rate, and arterial compliance, whereas maximum and mean catheter gradients were related only to the energy loss coefficient and flow rate. Of major importance, maximum systolic left ventricular wall stress increased greatly during hypertension (43 (23)%). The severity of AS may be partially masked by the presence of coexisting hypertension. The markers of AS severity should thus be interpreted with caution in hypertensive patients and be re-evaluated when the patient is in a normotensive state.Heart (British Cardiac Society) 04/2005; 91(3):354-61. · 5.01 Impact Factor