Time-varying effective mitral valve area: prediction and validation using cardiac MRI and Doppler echocardiography in normal subjects

2004 ◽  
Vol 287 (4) ◽  
pp. H1650-H1657 ◽  
Author(s):  
Andrew W. Bowman ◽  
Paul A. Frihauf ◽  
Sándor J. Kovács

Precise knowledge of the volume and rate of early rapid left ventricular (LV) filling elucidates kinematic aspects of diastolic physiology. The Doppler E wave velocity-time integral (VTI) is conventionally used as the estimate of early, rapid-filling volume; however, this implicitly requires the assumption of a constant effective mitral valve area (EMVA). We sought to evaluate whether the EMVA is truly constant throughout early, rapid filling in 10 normal subjects using cardiac magnetic resonance imaging (MRI) and contemporaneous Doppler echocardiography, which were synchronized via ECG. LV volume measurements as a function of time were obtained via MRI, and transmitral flow values were measured via Doppler echocardiography. The synchronized data were used to predict EMVA as a function of time during early diastole. Validation involved EMVA determination using 1) the short-axis echocardiographic images near the mitral valve leaflet tips, 2) the distance between leaflet tips in the echocardiographic parasternal long-axis view, and 3) the distance between leaflet tips from the MRI LV outflow tract view. Predicted EMVA values varied substantially during early rapid filling, and observed EMVA values agreed well with predictions. We conclude that the EMVA is not constant, and its variation causes LV volume to increase faster than is reflected by the VTI. These results reveal the mechanism of early rapid volumetric increase and directly affect the significance and physiological interpretation of the VTI of the Doppler E wave. Application to subjects in selected pathophysiological subsets is in progress.

2010 ◽  
Vol 298 (6) ◽  
pp. H1908-H1918 ◽  
Author(s):  
June Cheng-Baron ◽  
Kelvin Chow ◽  
Nee Scze Khoo ◽  
Ben T. Esch ◽  
Jessica M. Scott ◽  
...  

Left ventricular (LV) active relaxation begins before aortic valve closure and is largely completed during isovolumic relaxation (IVR), before mitral valve opening. During IVR, despite closed mitral and aortic valves, indirect assessments of LV volume have suggested volume increases during this period. The aim of this study is to measure LV volume throughout IVR and to determine the sources of any volume changes. For 10 healthy individuals (26.0 ± 3.8 yr), magnetic resonance imaging was used to measure time courses of LV volume, principal myocardial strains (circumferential, longitudinal, radial), and LV twist. Mitral leaflet motion was observed using echocardiography. During IVR, LV volume measurements showed an apparent increase of 4.6 ± 1.5 ml (5.0 ± 2.0% of the early filling volume change), the LV untwisted by 4.5 ± 1.9° (36.6 ± 18.0% of peak systolic twist), and changes in circumferential, longitudinal, and radial strains were +0.87 ± 0.64%, +0.93 ± 0.57%, and −1.46 ± 1.66% (4.2 ± 3.3%, 5.9 ± 3.3%, and 5.3 ± 7.5% of peak systolic strains), respectively. The apparent changes in volume correlated ( P < 0.01) with changes in circumferential, longitudinal, and radial strains ( r = 0.86, 0.69, and −0.37, respectively) and untwisting ( r = 0.83). The closed mitral valve leaflets were observed to descend into the LV throughout IVR in all subjects in apical four- and three-chamber and parasternal long-axis views by 6.0 ± 3.3, 5.1 ± 2.4, and 2.1 ± 5.0 mm, respectively. In conclusion, LV relaxation during IVR is associated with changes in principal strains and untwisting, which are all correlated with an apparent increase in LV volume. Since closed mitral and aortic valves ensure true isovolumic conditions, the apparent volume change likely reflects expansion of the LV myocardium and the inward bowing of the closed mitral leaflets toward the LV interior.


1988 ◽  
Vol 116 (3) ◽  
pp. 877-879 ◽  
Author(s):  
Dennis Halbe ◽  
Robert J. Bryg ◽  
Arthur J. Labovitz

2019 ◽  
Vol 16 (2) ◽  
pp. 41-46
Author(s):  
Rajan Paudel ◽  
Ram Kishor Sah ◽  
Man Bahadur KC ◽  
Deewakar Sharma ◽  
Arun Maskey ◽  
...  

Background and Aims: Determining the severity of mitral stenosis (MS) is important for both prognostic and therapeutic reasons. Measurement of Mitral valve area (MVA) by planimetry is gold standard and accurate but is highly operator dependent. Pressure Half Time (PHT) is affected by hemodynamic significance. In this Study we evaluated severity of mitral stenosis by mitral leaflet separation index (MLS index, MLSI). This new index could be useful surrogate measure of the MVA. Methods: This is a hospital based, cross-sectional observational study carried out in Shahid Gangalal National Heart Centre (SGNHC), Kathmandu, Nepal. Study included 82 patients with Rheumatic MS who had undergone echocardiographic examination from July 2018 to December 2018. The maximal separation of the mitral valve leaflet tips was measured from inner edge to inner edge in end diastole in the parasternal long axis and apical 4-chamber views. These two parameters were averaged to yield the MLSI. The index was compared with mitral valve area determined by planimetry method and PHT. Results: Of the 82 study subjects, majority were females 72 (85.4%). The mean age of study patients was 37.33±11.56 years. 30.5% had mild MS by planimetry, 31.7% had moderate MS and 37.8% had severe MS. There was a very strong correlation between MLS index and MVA by planimetry ( r = 0.89, p<0.001) and MVA by PHT (r=0.95, p<0.001). MLS index less than 0.73 cm can predict severe MS with 93.2% sensitivity and 89.3% specificity. On the other hand MLS index more than 1.035cm can predict mild MS with 70% sensitivity and 89.3% specificity. Strong correlation exists between MLS index and MV severity in presence atrial fibrillation (AF) (r=0.879) for planimetry and (r=0.835) for PHT and in presence of coexisting mitral regurgitation (MR) (r=0.89) for planimetry and (r=0.86) for PHT. Conclusion: MLSI has a strong correlation with MVA by planimetry and PHT. So, it can be used as a reliable method to assess severity of mitral stenosis and is a simple and easily obtainable. It has good correlation even in presence of AF and MR.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
I F Sales ◽  
M E Alcici ◽  
G R S A Athayde ◽  
V T Ribeiro ◽  
T D Diamantino ◽  
...  

Abstract Introduction Pulmonary hypertension (HP) has long been known to be a marker of poor outcome in patients with mitral stenosis (MS). Percutaneous mitral valvuloplasty (PMV) is currently the treatment of choice for MS, which results in improvement in HP. However, despite the successful valve opening, the regression of PH may be incomplete. This has been attributed to irreversible morphologic changes within the pulmonary vasculature. Purpose To assess the clinical, echocardiographic and hemodynamic parameters associated with an inadequate response of the pulmonary artery pressure (PAP) immediately after a successful PMV, and also the impact of residual PH on long-term outcome in these patients. Methods 181 patients undergoing PMV for rheumatic MS were enrolled. Invasive hemodynamic and echocardiographic measures were examined in all patients. Inadequate response of PAP was defined as the mean pulmonary artery pressure (mPAP) values unchanged at the end of the procedure. Long-term outcome was a composite endpoint of death, mitral valve replacement, repeat PMV, new onset of atrial fibrillation (AF), or stroke. Results The mean age was 44.1±12.6 years, and 157 patients were women (86.7%). In the overall population, mPAP decreased from 33.4±13.1 mmHg pre to 27.6±9.8 mmHg post (p<0.001), as mitral valve increased from 0.96±0.2 cm2 pre to 1.68±0.2 cm2 post (p<0.001) PMV. Following PMV, 10 patients developed severe mitral regurgitation and were excluded from the analysis. Of the 171 patients analyzed, 52 (30%) did not present reduction of mPAP immediately after the PMV. Transmitral pressure gradients were significantly greater and mitral valve area was smaller in those patients with unchanged mPAP after PMV than in those whose PAP had decreased. Systolic, diastolic and mPAP pressures as well as left atrial pressure were higher in those patients who had improvement in pulmonary pressures after PMV. Multivariate analysis revealed the following independent predictors of unchanged mPAP: AF (Odds ratio [OR] 2.7, 95% [confidence interval] CI 1.1 to 6.4), mitral valve area (OR 1.3, 95% CI 1.1 to 1.5), maximum mitral valve leaflets displacement (OR 0.8, 95% CI 0.7 to 0.9), and left ventricular compliance after PMV (OR 0.8, 95% CI 0.6 to 0.9). During a mean follow-up of 28 months, the endpoint was reached in 48 patients (26%). The pulmonary pressure response to PMV was not predictor of long-term events. Conclusions In a large cohort of patients with MS undergoing PMV, mean pulmonary artery pressure values do not reduce immediately after the procedure in 30% of the cases, despite adequate opening of the valve. The factors associated with inadequate PAP response following PMV were presence of AF, larger mitral valve area, reduced valve leaflets mobility and post procedural low left ventricular compliance. The early non-reduction of mPAP after PMV is not associated with adverse outcome.


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