Improved assessment of mitral valve stenosis by volumetric real-time three-dimensional echocardiography

OBJECTIVES: This study was performed to determine the feasibility, accuracy and reproducibility of real-time volumetric three-dimensional echocardiography (3-D echo) for the estimation of mitral valve area in patients with mitral valve stenosis. BACKGROUND: Planimetry of the mitral valve area (MVA) by two-dimensional echocardiography (2-D echo) requires a favorable parasternal acoustic window and depends on operator skill. Transthoracic volumetric 3-D echo allows reconstruction of multiple 2-D planes in any desired orientation and is not limited to parasternal acquisition, and could thus enhance the accuracy and feasibility of calculating MVA. METHODS: In 48 patients with mitral stenosis (40 women; mean age 61 +/- 13 years) MVA was determined by planimetry using volumetric 3-D echo and compared with measurements obtained by 2-D echo and Doppler pressure half-time (PHT). All measurements were performed by two independent observers. Volumetric data were acquired from an apical view. RESULTS: Although 2-D echo allowed planimetry of the mitral valve in 43 of 48 patients (89%), calculation of the MVA was possible in all patients when 3-D echo was used. Mitral valve area by 3-D echo correlated well with MVA by 2-D echo (r = 0.93, mean difference, 0.09 +/- 0.14 cm2) and by PHT (r = 0.87, mean difference, 0.16 +/- 0.19 cm2). Interobserver variability was significantly less for 3-D echo than for 2-D echo (SD 0.08cm2 versus SD 0.23cm2, p < 0.001). Furthermore, it was much easier and faster to define the image plane with the smallest orifice area when 3-D echo was used. CONCLUSIONS: Transthoracic real-time volumetric 3-D echo provides accurate and highly reproducible measurements of mitral valve area and can easily be performed from an apical approach.     

Application of the vena contracta method for the calculation of the mitral valve area in mitral stenosis

OBJECTIVES: The vena contracta is the narrowest region of the regurgitant or stenotic jet just downstream the orifice and reflects the size of that orifice. This study was performed to assess the accuracy of the vena contracta width (VCW) in evaluating the severity of mitral stenosis (MS) and to compare the mitral valve area (MVA) determined by VCW with MVAs obtained by other more traditional echocardiographic methods. METHODS: We studied 59 patients (43 females, 42 +/- 14 years) with MS. VCW was measured in the apical four chamber view by Doppler color flow mapping. The largest diameter of the VCW during diastole was measured for at least three cardiac cycles and averaged. MVA was calculated from the following equation: pir(2), where r = VCW/2. MVA was also determined by planimetry, the pressure half-time method, and by the Gorlin formula. RESULTS: In this study, the width of the vena contracta ranged from 0.89 to 1.73 cm (mean 1.30 +/- 0.21). MVA, calculated based on the VCW, ranged from 0.63 to 2.35 cm(2) (mean 1.36 +/- 0.41). MVA by VCW (1.36 +/- 0.41 cm(2)) showed good correlations with three comparative techniques: (1) the cross-sectional area by planimetry (1.35 +/- 0.36 cm(2), mean difference = 0.21 +/- 0.16 cm(2), y = 0.91x + 0.14, r = 0.79, SEE = 0.26 cm(2), p < 0.001); (2) the area derived from the Doppler pressure half-time (1.27 +/- 0.32 cm(2), mean difference = 0.22 +/- 0.19 cm(2), y = 0.97x + 0.13, r = 0.76, SEE = 0.27 cm(2), p < 0.001), and (3) the area derived from the Gorlin equation in the 18 patients who underwent catheterization (1.27 +/- 0.35 cm(2), mean difference = 0.19 +/- 0.16, y = 0.98x + 0.05, r = 0.81, SEE = 0.26 cm(2), p < 0.001). CONCLUSIONS: These findings suggest that Doppler color flow imaging of the MS jet in the vena contracta can provide an accurate estimation of MVA and appears to be potentially applicable in the assessment of the severity of MS.     

Planimetry of mitral valve stenosis by magnetic resonance imaging

OBJECTIVES: We sought to determine whether noninvasive planimetry of the mitral valve area (MVA) by magnetic resonance imaging (MRI) is feasible and reliable in patients with mitral stenosis (MS). BACKGROUND: Accurate assessment of MVA is particularly important for the management of patients with valvular stenosis. Current standard techniques for assessing the severity of MS include echocardiography (ECHO) and cardiac catheterization (CATH). METHODS: In 22 patients with suspected or known MS, planimetry of MVA was performed with a 1.5-T magnetic resonance scanner using a breath-hold balanced gradient echo sequence (true FISP). Data were compared with echocardiographically determined MVA (ECHO-MVA, n = 22), as well as with invasively calculated MVA by the Gorlin-formula at (CATH-MVA, n = 17). RESULTS: The correlation between MRI- and CATH-MVA was 0.89 (p < 0.0001), and the correlation between MRI- and ECHO-MVA was 0.81 (p < 0.0001). The MRI-MVA slightly overestimated CATH-MVA by 5.0% (1.60 +/- 0.45 cm(2) vs. 1.52 +/- 0.49 cm(2), p = NS) and ECHO-MVA by 8.1% (1.61 +/- 0.42 cm(2) vs. 1.48 +/- 0.42 cm(2), p < 0.05). On receiver-operating characteristic curve analysis, a value of MRI-MVA below 1.65 cm(2) indicated mitral stenosis (CATH-MVA < or =1.5 cm(2)), with a good sensitivity and specificity (89% and 75%, respectively). CONCLUSIONS: Magnetic resonance planimetry of the mitral valve orifice in mitral stenosis offers a reliable and safe method for noninvasive quantification of mitral stenosis. In the clinical management of patients with mitral stenosis, it has to be considered that planimetry by MRI slightly overestimates MVA, as compared with MVA calculated echocardiographically and at catheterization.     

Mechanisms of increase in mitral valve area and influence of anatomic features in double-balloon, catheter balloon valvuloplasty in adults with rheumatic mitral stenosis: a Doppler and two-dimensional echocardiographic study

To study the mechanism of increase in the mitral valve area (MVA) and the anatomic features of the mitral valve that may affect the results of catheter double-balloon valvuloplasty (CBV) in adult patients with mitral stenosis, Doppler and two-dimensional echocardiography was performed in 12 patients before and immediately after CBV. Immediately after CBV, there was an increase in the transverse diameter of the mitral valve orifice from 18 +/- 1.6 to 25 +/- 2.8 mm (mean +/- SD, p less than .001). The anterior angles at the commissure increased from 33 +/- 6 to 57 +/- 20 degrees (p less than .05) and the posterior angles from 36 +/- 9 to 54 +/- 14 degrees (p less than .05). The MVA was greater after CBV in patients with pliable mitral valves (2.6 +/- 0.7 cm2) compared with those with rigid mitral valves (1.9 +/- 0.8 cm2; p = .08). After CBV, MVA was smaller in patients with calcification (2.1 +/- 0.2 cm2) compared with those without (2.7 +/- 0.5 cm2; p = .10) and in those with subvalvular disease (2.0 +/- 0.6 cm2) compared with those without (2.9 +/- 0.9 cm2;p = .03). The MVA by Doppler ultrasound before CBV (1.0 +/- 0.2 cm2) correlated well with MVA by cardiac catheterization (1.0 +/- 0.3 cm2; r = .8, SEE = 0.2 cm2). After CBV, the correlation of MVA by Doppler ultrasound (2.0 +/- 0.5 cm2) with MVA by cardiac catheterization (2.4 +/- 0.8 cm2) was poor (r = .3, SEE = 0.44 cm2).(ABSTRACT TRUNCATED AT 250 WORDS)     

Validity of the proximal isovelocity surface area color Doppler method for calculating the valve area in patients with mitral stenosis; comparison with the two-dimensional echocardiographic method]

BACKGROUND. The proximal isovelocity surface area (PISA) method, assessed by color Doppler echocardiography, has gained acceptance as a means of calculating flow rate through regurgitant orifice. The method can also be used to derive mitral valve area (MVA), by continuity equation, in patients with mitral stenosis (MS). The aim of this study was to compare the PISA method with the two-dimensional echocardiographic planimetry (2D) method and pressure half-time method (PHT) in MVA calculations in a group of 37 patients with MS. METHODS AND RESULTS. All of these patients had satisfactory MVA by 2D method. There were 22 female and 15 male; age 56 +/- 11 years (range 32-71); 19 were in sinus rhythm (SR) and 18 in atrial fibrillation (AF); 17 patients had pure MS, while the remaining 20 had associated mitral regurgitation (MR); in 23 patients the orifice morphology was circular or elliptic, and was defined as regular; while in 14 patients the morphology was irregular for the presence of two or more nodular calcifications on the commissures or leaflet's edges. MVA by PISA method was calculated assuming a uniform radial flow convergence region along a hemispherical surface, according to the formula: MVA = 2 pi r2 Vn(1-cos theta)/Vmax; where r was the PISA radius measured in 2D from the first alias to the mitral leaflet's edge; Vn was the flow velocity at radial distance from the mitral orifice; Vmax was the peak transmitral velocity by CW Doppler; 1-cos theta was a factor that accounted for the inflow angle formed by the mitral leaflets. The Nyquist limit was lowered to 29 cm/sec. Alpha angle formed by the mitral leaflets ranged between 86 degrees and 134 degrees; average 110 degrees +/- 10 degrees. 2D MVA was 1.33 +/- 0.37 cm2; range 0.69-2.2 cm2; PHT MVA was 1.29 +/- 0.34 cm2; range 0.70-2.1 cm2; PISA MVA was 1.18 +/- 0.36 cm2; range 0.47-1.95 cm2. The PISA method underestimates MVA by 0.15 +/- 0.21 cm2, in comparison with the 2D method; and by 0.11 +/- 0.18 cm2 in comparison with PHT method (p ns). The correlation between 2D and PISA MVA was: r = 0.84; p < 0.001; y = 0.83x + 0.06; 95% confidence intervals +/- 0.40 cm2; and between PHT and PISA MVA was: r = 0.79; y = 0.84x + 0.09; p < 0.001; 95% confidence intervals +/- 0.46 cm2. The correlation coefficient was similarly good in patients with SR or AF, and did not significantly change in patients with pure MS or MS+MR; neither did it vary with respect to the orifice morphology (p < 0.001 for all the variables considered), except for the correlation PHT-PISA in the group of patients with irregular orifice morphology (r = 0.70; p = 0.005). The interobserver and intraobserver variability were, respectively: 2.2% and 4.4% for 2D MVA; 3.4% and 3.8% for PHT MVA; 5.2% and 3.5% for the PISA radius; 6.1% and 4.4% for the alpha angle; 10.2% and 7.2% for PISA MVA (F ratio of variances ns). CONCLUSIONS. In conclusion, the PISA method allows accurate assessment of MVA in patients with MS, regardless of cardiac rhythm or additional MR. Moreover, our study suggests that orifice morphology does not affect the accuracy of this method.     

Quantitative assessment of aortic stenosis by three-dimensional anyplane and three-dimensional volume-rendered echocardiography

Aortic stenosis is a challenge for three-dimensional (3-D) echocardiographic image resolution. This is the first study evaluating both 3-D anyplane and 3-D volume-rendered echocardiography in the quantification of aortic stenosis. In 31 patients, 3-D echocardiography was performed using a multiplane transesophageal probe. Within the acquired volume dataset, five parallel cross sections were generated through the aortic valve. Subsequently, volume-rendered images of the five cross sections were reconstructed. The smallest orifice areas of both series were compared with the results obtained by two-dimensional (2-D) transesophageal planimetry and those calculated by Doppler continuity equation. No significant differences were found between Doppler (0.76 +/- 0.18 cm(2)), 2-D echocardiography (0.78 +/- 0.24 cm(2)), and 3-D anyplane echocardiography (0.72 +/- 0.29 cm(2)). The orifice area measured smaller (0.54 =/- 0.31 cm(2), P < 0.001) by 3-D volume-rendered echocardiography. Bland-Altmann analysis indicated that for 3-D anyplane echocardiography, the mean difference from Doppler and 2-D echocardiography was - 0.04 +/- 0.24 cm(2) and - 0.06 +/- 0.23 cm(2), respectively. For 3-D volume-rendered echocardiography, the mean difference was -0.23 +/- 0.24 cm(2) and - 0.25 +/- 0.26 cm(2), respectively. In the subgroup with good resolution in the 3-D dataset, close limits of agreement were obtained between 3-D echocardiography and each of the reference methods, while the subgroup with poor resolution showed wide limits of agreement. In conclusion, planimetry of the stenotic aortic orifice by 3-D volume-rendered echocardiography is feasible but tends to underestimate the orifice area. Three-dimensional anyplane echocardiography shows better agreement with the reference methods. Accuracy is influenced strongly by the structural resolution of the stenotic orifice in the 3-D dataset.     

Can the Proximal Isovelocity Surface Area Method Calculate Stenotic Mitral Valve Area in Patients with Associated Moderate to Severe Aortic Regurgitation? Analysis Using Low Aliasing Velocity of 10% of the Peak Transmitral Velocity

To assess the ability of the proximal isovelocity surface area (PISA) method to accurately measure the stenotic mitral valve area (MVA), and to assess whether aortic regurgitation (AR) affects the calculation, we compared the accuracy of the PISA method and the pressure half-time (PHT) method for determining MVA in patients with and without associated AR by using two-dimensional echocardiographic planimetry as a standard. The study population consisted of 45 patients with mitral stenosis. Seventeen of the 45 patients had associated moderate-to-severe AR. The PISA method was performed using low aliasing velocity (AV) of 10% of the peak transmitral velocity, which provided the most accurate estimation of MVA when compared with planimetry. The maximal radius r of the PISA was measured from the orifice to blue-red aliasing interface. Using the PISA method, MVA was calculated as (2pir(2)) x theta / 180 x AV/Vmax, where theta was the inflow angle formed by mitral leaflets, AV was the aliasing velocity (cm/sec), and Vmax was the peak transmitral velocity (cm/sec). MVA by the PISA method correlated well with planimetry both in patients with AR (r = 0.90, P < 0.001, SEE = 0.17 cm(2)) and without AR (r = 0.92, P < 0.001, SEE = 0.16 cm(2)). However, MVA by the PHT method did not correlate as well with planimetry (r = 0.57, P < 0.05, SEE = 0.37 cm(2)) in patients with associated AR, and the PHT method produced a significant overestimation (24%) of MVA obtained by planimetry in these patients. We conclude that the PISA method allows accurate estimation of MVA and is not influenced by AR.     

Planimetry and Transthoracic Two-Dimensional Echocardiography in Noninvasive Assessment of Aortic Valve Area in Patients With Valvular Aortic Stenosis

Objectives. The aim of this study was to evaluate the reliability of transthoracic two-dimensional echocardiography in measuring aortic valve area (AVA) by planimetry.Background. Planimetry of AVA using two-dimensional transesophageal echocardiographic images has been reported to be a reliable method for measuring AVA in patients with aortic stenosis. Recent advances in resolution of two-dimensional echocardiography permit direct visualization of an aortic valve orifice from the transthoracic approach more easily than before.Methods. Forty-two adult patients with valvular aortic stenosis were examined. A parasternal short-axis view of the aortic valve was obtained with transthoracic two-dimensional echocardiography. AVA was measured directly by planimetry of the inner leaflet edges at the time of maximal opening in early systole. AVA was also measured by planimetry using transesophageal echocardiography, by the continuity equation and by cardiac catheterization (Gorlin formula).Results. In 32 (76%) of the 42 study patients, AVA could be detected by using the transthoracic planimetry method. There were good correlations between results of transthoracic two-dimensional echocardiographic planimetry and the continuity equation (y = 0.90x + 0.09, r = 0.90, p < 0.001, SEE = 0.09 cm²), transesophageal echocardiographic planimetry (y = 1.05x − 0.02, r = 0.98, p < 0.001, SEE = 0.04 cm²) and the Gorlin formula (y = 1.02x + 0.05, r = 0.89, p < 0.001, SEE = 0.10 cm²).Conclusions. Transthoracic two-dimensional echocardiography provides a feasible and reliable method in measuring AVA in patients with aortic stenosis.     

Clinical applicability for the assessment of the valvular mitral stenosis severity with Doppler echocardiography and the proximal isovelocity surface area (PISA) method

Evaluation of the severity of valvular mitral stenosis and measurements of the effective rheumatic mitral valve area by noninvasive echocardiography has been well accepted. The area is measured by the two-dimensional planimetry (PLM) method and the Doppler pressure half-time (PHT) method. Recently, the proximal isovelocity surface area (PISA) by color Doppler technique has been used as a quantitative measurement for valvular heart disease. However, this method needs more validation. The aim of this study was therefore to investigate the clinical applicability of the PISA method in the measurements of effective mitral valve area in patients with rheumatic valvular heart disease. Forty-seven patients aged from 23 to 71 years, with a mean age of 53 +/- 13 (25 male and 22 female, 15 with sinus rhythm, mean heart rate of 83 +/- 14 beats per minute, with rheumatic valvular mitral stenosis without hemodynamically significant mitral regurgitation) were included in the study. Effective mitral valve area (MVA) derived by the PISA method was calculated as follows: 2 x Pi x (proximal aliasing color zone radius)2x aliasing velocity/peak velocity across mitral orifice. Effective mitral valve areas measured by three different methods (PLM, PHT, and PISA) were compared and correlated with those calculated by the "gold standard" invasive Gorlin's formula. The MVA derived from PHT, PLM, PISA and Gorlin's formula were 1.00 +/- 0.31cm2, 0.99 +/- 0.30 cm2, 0.95 +/- 0.30 cm2 and 0.91 +/- 0.29 cm2, respectively. The correlation coefficients (r value) between PHT, PLM, PISA, and Gorlin's formula, respectively, were 0.66 (P = 0.032, SEE = 0.64), 0.67 (P = 0.25, SEE = 0.72) and 0.80 (P = 0.002, SEE = 0.53). In conclusion, the PISA method is useful clinically in the measurement of effective mitral valve area in patients with rheumatic mitral valve stenosis. The technique is relatively simple, highly feasible and accurate when compared with the PHT, PLM, and Gorlin's formula. Therefore, this method could be a promising supplement to methods already in use.     

Comparison of accuracy of aortic valve area assessment in aortic stenosis by real time three-dimensional echocardiography in biplane mode versus two-dimensional transthoracic and transesophageal echocardiography

Our aim was to validate the clinical feasibility of assessment of the area of the aortic valve orifice (AVA) by real time three-dimensional echocardiography (RT3DE) in biplane mode by planimetry and to compare it with the echo-Doppler methods more commonly used to evaluate valvular aortic stenosis (AS).RT3DE in biplane mode is a novel technique that allows operators to visualize the aortic valve orifice anatomy in any desired plane orientation. Its usefulness and accuracy have not previously been established.Using this technique, we studied a series of patients with AS and compared the results with those obtained by two-dimensional transesophageal echocardiography (TEE) planimetry and two-dimensional transthoracic echocardiography using the continuity equation (TTE-CE). RT3DE planimetries in biplane mode were measured by two independent observers. Bland-Altman analysis was used to compare these two methods.Forty-one patients with AS were enrolled in the study (15 women, 26 men, mean age 73.5 +/- 8.2 years). RT3DE planimetry was feasible in 92.7%. Average AVA determined by TTE-CE was 0.76 +/- 0.20 cm, by TEE planimetry 0.73 +/- 0.1 cm, and by RT3DE planimetry 0.76 +/- 0.20 cm(2). The average differences in AVA were-0.001 +/- 0.254 cm(2) and 0.03 +/- 0.155 cm(2) (RT3DE/TEE). The correlation coefficient for AVA (RT3DE/TTE-CE) was 0.82 and for AVA (RT3DE/TEE) it was 0.94, P < 0.0001. No significant intra- and interobserver variability was observed. In conclusion, RT3DE in biplane mode provides a feasible and reproducible method for measuring the area of the aortic valve orifice in aortic stenosis.     

Influence of mitral valve morphology on double-balloon catheter balloon valvuloplasty in patients with mitral stenosis. Analysis of factors predicting immediate and 3-month results

To determine if mitral valve morphology influences the results of double-balloon catheter balloon valvuloplasty (CBV) for mitral stenosis, two-dimensional echocardiography was performed in 33 patients before CBV. The two-dimensional echocardiographic features of leaflet motion, leaflet thickness, subvalvular disease, and commissural calcium and 14 pre-CBV clinical and hemodynamic variables were then correlated to the immediately post-CBV mitral valve area (MVA). At 3 months after CBV, the two-dimensional echocardiographic features of patients with a 25% or greater decrease in MVA were analyzed to determine whether mitral valve morphology had influenced early results. Leaflet motion had a significant relation with the immediately post-CBV MVA (r = 0.67, y = 4.5x + 0.29, and SEE = 0.45). Leaflet thickness had a weak and negative relation (r = -0.48, y = -0.17x + 2.6, and SEE = 0.53) with the immediately post-CBV MVA. Subvalvular disease and commissural calcium had no significant relation to the immediately post-CBV MVA. When leaflet motion and leaflet thickness were considered as grades of mild, moderate, and severe and assigned a score of 0-2, patients with more severe disease (total score, 3 or 4) had a significant lower MVA immediately after CBV (1.4 +/- 0.4 cm2) than patients with moderate disease (score, 1-2; MVA, 2.0 +/- 0.5 cm2; p less than 0.05) or mild disease (score, 0; MVA, 2.6 +/- 0.6 cm2; p less than 0.05). In 96% of patients with a total score of 0-2, the immediately post-CBV MVA was more than 1.4 cm2, whereas only 29% of patients with a total score of 3-4 had an immediately post-CBV MVA of more than 1.4 cm2. Analysis of all two-dimensional echocardiographic features showed that leaflet motion score had the strongest influence on the post-CBV MVA (p less than 0.001). When all two-dimensional echocardiographic, clinical, and hemodynamic variables were included, leaflet motion, effective balloon dilating area, and cardiac output were the strongest predictors of the immediate post-CB MVA.(ABSTRACT TRUNCATED AT 400 WORDS)     

Comparison of direct planimetry of mitral valve regurgitation orifice area by three-dimensional transesophageal echocardiography to effective regurgitant orifice area obtained by proximal flow convergence method and vena contracta area determined by color Doppler echocardiography

Direct measurement of anatomic regurgitant orifice area (AROA) by 3-dimensional transesophageal echocardiography was evaluated for analysis of mitral regurgitation (MR) severity. In 72 patients (age 70.6 ± 13.3 years, 37 men) with mild to severe MR, 3-dimensional transesophageal echocardiography and transthoracic color Doppler echocardiography were performed to determine AROA by direct planimetry, effective regurgitant orifice area (EROA) by proximal convergence method, and vena contracta area (VCA) by 2-dimensional color Doppler echocardiography. AROA was measured with commercially available software (QLAB, Philips Medical Systems, Andover, Massachusetts) after adjusting the first and second planes to reveal the smallest orifice in the third plane where planimetry could take place. AROA was classified as circular or noncircular by calculating the ratio of the medial-lateral distance above the anterior-posterior distance (≤1.5 compared to >1.5). AROA determined by direct planimetry was 0.30 ± 0.20 cm2, EROA determined by proximal convergence method was 0.30 ± 0.20 cm2, and VCA was 0.33 ± 0.23 cm2. Correlation between AROA and EROA (r = 0.96, SEE 0.058 cm2) and between AROA and VCA (r = 0.89, SEE 0.105 cm2) was high considering all patients. In patients with a circular regurgitation orifice area (n = 14) the correlation between AROA and EROA was better (r = 0.99, SEE 0.036 cm2) compared to patients with noncircular regurgitation orifice area (n = 58, r = 0.94, SEE 0.061 cm2). Correlation between AROA and EROA was higher in an EROA ≥0.2 cm2 (r = 0.95) than in an EROA <0.2 cm2 (r = 0.60). In conclusion, direct measurement of MR AROA correlates well with EROA by proximal convergence method and VCA. Agreement between methods is better for patients with a circular regurgitation orifice area than in patients with a noncircular regurgitation orifice area.     

Value of mitral valve tenting volume determined by real-time three-dimensional echocardiography in patients with functional mitral regurgitation

This study sought to evaluate mitral valve tenting volume (TnV) as a clinical parameter using real-time 3-dimensional echocardiography in patients with functional mitral regurgitation (MR). In 27 patients with functional MR and 4 controls without mitral disease, real-time 3-dimensional echocardiographic images were obtained to measure TnV frame by frame from presystole to end-systole. The maximal and minimal TnVs during systole were identified in each patient, and mitral annular areas and tenting heights were also measured. Using 2-dimensional echocardiography, tenting area (TnA) was measured from the apical long-axis, apical 4-chamber, and apical 2-chamber views. The regurgitant orifice area was measured by the proximal isovelocity surface area method. Maximal and minimal TnVs occurred at the time of 2 +/- 6% and 78 +/- 6% of whole systolic duration, respectively, and the systolic percentage change of TnV was related to that of tenting height but not to that of mitral annular area. TnA on the long-axis images was significantly larger than that on the 4- and 2-chamber images (2.5 +/- 1.4 vs 1.7 +/- 1.3 and 1.9 +/- 1.4 cm(2), respectively, p <0.001). Regurgitant orifice area was significantly correlated with maximal TnV (r = 0.90), minimal TnV (r = 0.86), and TnA on the long-axis (r = 0.79), 4-chamber (r = 0.75), and 2-chamber (r = 0.73) images. Among minimal TnV and 3 TnAs, minimal TnV was the only independent determinant of regurgitant orifice area (p <0.001). Minimal TnV >or=3.90 ml identified significant functional MR with a sensitivity of 86% and a specificity of 100%. In conclusion, TnV derived from real-time 3-dimensional echocardiography is a preferable novel single index for assessing mitral valve tethering in functional MR to TnA that is dependent on the location of 2-dimensional planes.     

Non-invasive assessment of mitral valve area during percutaneous balloon mitral valvuloplasty: role of real-time 3D echocardiography.

BACKGROUND: In the last decade, multiple studies depicted discrepancies between mitral valvular orifice area (MVA) measurements obtained with the pressure half-time (PHT) method and invasive methods during the immediate post-percutaneous mitral valvuloplasty (PMV) period. Our aim was to assess the accuracy of Real-Time 3D echo (RT3D) to measure the MVA in the immediate post-PMV period. The invasively determined MVA was used as the gold standard. METHODS AND RESULTS: We studied 29 patients with rheumatic mitral stenosis from two centres (27 women; mean age 48.2+/-11.3 years), all of which had underwent PMV. MVA was calculated before and after PMV using the PHT method, 2D echo planimetry, RT3D echo planimetry and invasive determination (Gorlin's method). The RT3D MVA assessment showed a better agreement with the invasively derived MVA before and in the immediate post-PMV period (Bland-Altman analysis: Average difference between both methods and limits of agreement: 0.01 (-0.31 to 0.33) cm(2) and -0.12 (-0.71 to 0.47) cm(2)) before and immediately after the PMV, respectively. CONCLUSIONS: RT3D is a feasible and accurate technique for measuring MVA in patients with RMVS. It has the best agreement with the invasively determined MVA, particularly in the immediate post-PMV period.     

Comparison of 64-slice computed tomography planimetry and Doppler echocardiography in the assessment of aortic valve stenosis

BACKGROUND AND AIM of the study: The study aim was to compare, prospectively, the planimetry of aortic stenosis on 64-slice computed tomography (CT), with the area calculated by Doppler transthoracic echocardiography (TTE) in symptomatic patients evaluated before potential aortic valve replacement. METHODS: Fifty-two consecutive patients (27 males, 25 females; mean age 74 +/- 10 years) admitted to the authors' institution during 2005 were evaluated with 64-slice CT and Doppler TTE. The time interval between the two evaluations was 2 +/- 1 weeks. Planimetry of the anatomic orifice area (AOA) drawn on 64-slice CT was compared to the effective area determined by Doppler TTE by Bland and Altman analysis, and the anatomic area threshold value corresponding to a significant effective aortic stenosis (50.75 cm2) was determined by receiver operating characteristic (ROC) analysis. RESULTS: The aortic orifice area measured by 64-slice CT correlated well with the effective area (r = 0.76; p <0.0001), but was significantly greater, with a systematic overestimation (0.132 cm(2)) and a variability of 0.239 cm(2). There was good agreement between planimetry determined by two independent radiologists (difference = 0.002, variability = 0.115 cm(2)). ROC analysis showed that a threshold value of 0.95 cm(2) as measured by 64-slice CT planimetry identifies significant aortic stenosis with sensitivity, specificity, accuracy, positive and negative predictive values of 82%, 77%, 81%, 91% and 59%, respectively. CONCLUSION: 64-slice CT is a reproducible and reliable non-invasive method to evaluate aortic valve stenosis compared to the reference method of Doppler TTE. Indeed, the CT approach could replace the latter evaluation when measurements used in the continuity equation are inadequate.     

Determination of stenotic mitral valve area using Doppler echocardiography. A comparison with hemodynamic studies

In order to assess the reliability of Doppler echocardiography in the determination of mitral valve area (MVA) 21 consecutive patients (pts) affected by rheumatic disease and mitral valve stenosis (MS) were analyzed by continuous wave doppler echocardiography (CWD). Cardiac catheterization (cath) was performed within 24 hours from echocardiographic examination. MVA by CWD was calculated with a computerized system from the "pressure half-time" (T1/2) using the equation: 220/T1/2 in cm2. MVA was calculated from cath data by applying the modified Gorlin formula. MVA determined by CWD ranged from 0.9 to 2.8 cm2 (mean 1.39 +/- 0.55). MVA determined by Gorlin formula ranged from 0.5 to 2.8 cm2 (mean 1.31 +/- 0.63). The correlation between CWD and cath was good (r = 0.93, SEE = 0.19 cm2, P less than 0.001). In conclusion this study indicates that CWD is quite accurate in estimation of MVA and can reliably discriminate the "critical" size of the orifice. CWD has the advantage of allowing MVA determination in patients with associated mitral regurgitation.     

Ventricular stroke work loss: validation of a method of quantifying the severity of aortic stenosis and derivation of an orifice formula

Because aortic stenosis results in the loss of left ventricular stroke work (due to resistance to flow through the valve and turbulence in the aorta), the percentage of stroke work that is lost may reflect the severity of stenosis. This index can be calculated from pressure data alone. The relation between percent stroke work loss and anatomic aortic valve orifice area (measured by planimetry from videotape) was investigated in a pulsatile flow model. Thirteen valves were studied (nine human aortic valves obtained at necropsy and four bioprosthetic valves) at stroke volumes of 40 to 100 ml, giving 57 data points. Valve area ranged from 0.3 to 2.8 cm2 and mean systolic pressure gradient from 3 to 84 mm Hg. Percent stroke work loss, calculated as mean systolic pressure gradient divided by mean ventricular systolic pressure x 100%, ranged from 7 to 68%. It was closely related to anatomic orifice area with an inverse exponential relation and was not significantly related to flow (r = -0.15). An orifice formula was derived that predicted anatomic orifice area with a 95% confidence interval of +/- 0.5 cm2 (orifice area [cm2] = 4.82 [2.39 x log percent stroke work loss], r = -0.94, SEE = 0.029). These results support the clinical use of percent stroke work loss as an easily obtained index of the severity of aortic stenosis.     

Effect of antecedent systemic hypertension on subsequent left ventricular dilation after acute myocardial infarction (from the Survival and Ventricular Enlargement trial)

Whether antecedent systemic hypertension influences the risk of subsequent left ventricular (LV) dilation in patients after an acute myocardial infarction with LV systolic dysfunction is unclear. We assessed echocardiographic evidence of ventricular remodeling from baseline (mean +/- SD 11 +/- 3 days) to 2 years after an acute myocardial infarction in 122 hypertensive (defined as a history of treated hypertension, baseline systolic blood pressure > or =140 or baseline diastolic blood pressure > or =90 mm Hg) and 334 nonhypertensive patients in the Survival and Ventricular Enlargement echocardiographic substudy. Compared with nonhypertensives, baseline heart size, defined as the sum of the average short- and long-axis LV cavity areas, was similar (70.1 +/- 11.9 vs 68.8 +/- 11.2 cm(2), p = 0.33 at end-diastole; 50.1 +/- 11.3 vs 48.8 +/- 10.8 cm(2), p = 0.31 at end-systole), but short-axis LV myocardial area (24.7 +/- 4.3 vs 25.7 +/- 5.0 cm(2), p = 0.043) and wall thickness (1.15 +/- 0.16 vs 1.21 +/- 0.17 cm, p = 0.004) at end-diastole were greater among hypertensives. The myocardial infarct segment lengths were similar in the 2 groups (p = 0.22). Although LV cavity areas increased significantly in the 2 groups from baseline to 2 years (p < or =0.001), the increase was significantly greater in hypertensives than in nonhypertensives (+5.6 +/- 11.5 vs +2.2 +/- 10.7 cm(2), p = 0.005 at end-diastole; +6.23 +/- 12.75 vs +2.94 +/- 11.4 cm(2), p = 0.012 at end-systole). There was no concomitant difference in the change in LV myocardial area or LV wall thickness between the 2 groups (p >0.30). After adjusting for known confounders, antecedent hypertension was associated with a doubling of the risk of LV dilation (50.8% vs 37.7%, odds ratio 2.09, 95% confidence interval 1.27 to 3.45, p = 0.004). This association was not modified by diabetes mellitus, myocardial infarct segment length, or captopril use (all p values for interaction >0.10). We conclude that antecedent hypertension is associated with subsequent LV dilation in patients after acute myocardial infarction with LV systolic dysfunction.     

Valve orifice area in aortic stenosis evaluated by planimetry, Gorlin and continuity equations: a prospective study.

In evaluation of the severity of aortic valve stenosis, multiple parameters can be determined. All of them, except valve orifice area, are influenced by other factors such as cardiac output, heart rate or aortic insufficiency. OBJECTIVES: This is a prospective study which proposes, in the determination of the valve orifice area in aortic stenosis, to evaluate the accuracy of and correlation between three methods--planimetry by multiplane transesophageal echocardiography, the continuity equation by transthoracic echocardiography, and invasive measurement using the Gorlin formula. METHODS: Forty-five patients with known calcified valvular aortic stenosis 27 men, mean age 70 +/- 10 years, (range 27-82), were studied. In all patients the area was determined by planimetry and by the continuity equation. In 25 (56%) patients invasive measurements were obtained using the Gorlin formula. RESULTS: Evaluation of the valve orifice area by planimetry was easily performed and did not prolong the duration of the exam, except in five patients (11%). The area determined by the continuity equation had a mean value of 0.74 +/- 0.25 cm2, by planimetry 0.74 +/- 0.24 cm2 and by the Gorlin formula 0.65 +/- 0.17 cm2. Correlations between areas obtained by the three methods used were: continuity equation and planimetry 0.82; continuity equation and Gorlin formula 0.51; and planimetry and Gorlin formula 0.80. Concordance analysis (Bland and Altman's method) gave mean (Mn) values for the differences in the areas determined by the Gorlin formula and the continuity equation of 0.01 +/- 0.15 cm2 (Mn - 2SD = -0.29, Mn + 2SD = 0.30). The estimated value by the Gorlin formula and planimetry was 0.02 +/- 0.10 (Mn - 2SD = -0.19, Mn + 2SD = 0.23). CONCLUSIONS: 1) Planimetry of the valve orifice area by transesophageal echocardiography is feasible and does not prolong the duration of the exam in the majority of patients. 2) The strong correlation and the results of concordance analysis, in the determination of valve orifice area, between traditional invasive methods and planimetry, support the use of this noninvasive method in clinical practice.