Measurement of vena contracta width for the assessment of severity of mitral stenosis

This study was designed to test whether vena contracta width (VCW) measured by color Doppler flow could be used to assess the severity of mitral stenosis (MS). A secondary objective was to determine the cut-off value of VCW for the prediction of severe MS. We studied 47 consecutive patients with MS (mean age, 50 ± 11 years; 34 females) who did not have more than mild mitral regurgitation. We compared VCW with conventional methods for determining mitral valve area (MVA). Mitral valve area was assessed by one observer using continuity equation (CE), pressure half-time (PHT), and planimetry in the parasternal short axis view. Vena contracta width was measured in the same patients by two observers (blinded to the MVA data) using the apical four-chamber view by color Doppler flow. Vena contracta width measurements were compared with MVA by CE, PHT, and planimetry. The MVA determined by CE, PHT, and planimetry was 1.19 ± 0.42, 1.31 ± 0.53, and 1.27 ± 0.43 cm², respectively. The VCW in patients with MVA <1 cm², 1–1.5 cm², and >1.5 cm² (calculated by the CE method) was 0.77 ± 0.19, 1.13 ± 0.16, and 1.36 ± 0.24 cm, respectively. Vena contracta width was significantly correlated to MVA by planimetry (r = 0.756, P < 0.001), PHT (r = 0.673, P < 0.001), and CE (r = 0.813, P < 0.001). The VCW of patients with MVA ≤1 cm² was significantly smaller than that of patients with MVA >1 cm² determined by the CE method (0.77 ± 0.19 vs 1.26 ± 0.26, P < 0.001). Vena contracta width measurement of 1 cm or less had a sensitivity of 88% and a specificity of 77% for the prediction of severe MS. These results demonstrate that the correlations between VCW and MVA measured by conventional methods were highly significant. In addition, these results suggest that VCW ≤1 cm may indicate the presence of severe mitral stenosis.     

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.     

Sequential assessment of mitral valve area during diastole using colour M-mode flow convergence analysis: new insights into mitral stenosis physiology.

AIMS: In mitral stenosis (MS) transvalvular flow and velocity continually change throughout diastole but for mitral valve area (MVA), flow-dependent variations (valve reserve) are unknown. These physiologic changes can be studied by the proximal isovelocity surface area (PISA) method, using the high temporal resolution of colour M-mode, essential for simultaneous measurements of flow and velocity. Hence, we aimed to validate the colour M-mode PISA method for measurement of MVA in MS and to define using this method the physiologic flow-dependent changes of MVA during diastole. METHODS AND RESULTS: In 50 patients with native MS, MVA was measured by planimetry (MVA-2D), Doppler pressure half-time (MVA-PHT), and two-dimensional PISA (2D-PISA). MVA measurement by colour M-mode PISA in early diastole (M-PISA) (1.27+/-0.46 cm(2)) with rigorously timed flow and velocity measurements by continuous wave Doppler did not differ and correlated well with MVA-2D (1.29+/-0.44 cm(2), p=0.59; r=0.85, p<0.001) and MVA-PHT (1.30+/-0.41 cm(2), p=0.52; r=0.80, p<0.001). In contrast a trend towards underestimation of MVA by 2D-PISA was observed (1.23+/-0.42 cm(2); p=0.10 and p=0.07). Timed analysis of transvalvular haemodynamics at early, mid, mid-late, and late diastole showed marked changes in flow and velocities (both p<0.0001) but not in MVA (respectively 1.27+/-0.46, 1.29+/-0.47, 1.28+/-0.51 and 1.27+/-0.49 cm(2); ns). CONCLUSIONS: In MS, the high temporal resolution of colour M-mode PISA allows accurate MVA measurements. It also allows for the first time, sequential MVA assessment during diastole. Notwithstanding marked flow and velocities changes, MVA remained unchanged throughout diastole underscoring the lack of flow-related valvular reserve in MS.     

A nomogram for measurement of mitral valve area by proximal isovelocity surface area method

INTRODUCTION: Although its accuracy has been documented in many studies, the proximal isovelocity surface area (PISA) method is not used widely for mitral valve area (MVA) measurement. In this study, we prepared a new nomogram and tested its use in MVA assessment. MATERIAL AND METHODS: The study included 23 patients (age: 27 +/- 5 years) with mitral stenosis, of whom 7 were in atrial fibrillation. The MVA was measured by four methods: planimetry (PL) (reference method), pressure-half time (PHT), conventional PISA (CP), and nomogram (Nomo) methods. The nomogram included two unknowns: (1) r; the radius of the first PISA section; (2) a; the length of the border opposite to the PISA angle in the triangle with both adjacent borders of 1 cm. The nomogram was also tested for its popularity potential by eight echocardiographers, none of whom were included in the author list. RESULTS: Mean MVA(PL) was 1.85 +/- 0.53 cm(2) (range: 0.72-2.99), mean MVA(PHT) was 1.72 +/- 0.56 cm(2) (range: 0.91-3.30), mean MVA(CP) was 1.69 +/- 0.45 cm(2) (range: 0.97-2.54), and MVA(Nomo) was 1.70 +/- 0.44 cm(2) (0.96-2.49). The nomogram correlated with planimetry (r = 0.87; P < 0.001), pressure half-time (r = 0.71; P < 0.001) and conventional PISA (r = 0.99; P = 0.000) methods. The nomogram method also correlated with planimetry in patients with atrial fibrillation (r = 0.81; P = 0.026). The echocardiographers found that the nomogram is superior to the planimetry and conventional PISA methods but inferior to the pressure half-time method in terms of simplicity. CONCLUSION: The new nomogram is potentially helpful in measurement of MVA. It may be used as an additional method in assessing severity of mitral stenosis.     

Usefulness of three-dimensionally guided assessment of mitral stenosis using matrix-array ultrasound

Two-dimensional (2-D) planimetry is limited by the technical demands, time, and observer variability required to locate the minimal orifice area, limiting the confident clinical reporting of mitral valve area (MVA). In 27 consecutive patients, MVA was determined independently by 2 observers using the conventional 2-D method and a new 3-D-guided method. Using a matrix-array probe, the valve was visualized in a long-axis view and a cursor steered to intersect the leaflet tips and provide a perpendicular short-axis plane viewed side-by-side. Two-dimensional and 3-D-guided methods allowed planimetry in 24 patients. Consistent with better orifice localization, 3-D guidance eliminated the overestimation of internal orifice diameters in the planimetered short-axis view relative to the limiting diameter defined by the long-axis view (for 3-D guidance, 0.73 +/- 0.20 vs 0.73 +/- 0.21 cm, p = 0.98, vs 0.90 +/- 0.27 cm in the 2-D short-axis view, p <0.01). Accordingly, mean values for the smallest orifice area by 3-D guidance were less than by 2-D imaging (1.4 +/- 0.5 vs 1.5 +/- 0.5 cm(2), p <0.01), changing the clinical severity classification in 11 of 24 patients (46%). The 2-D method also overestimated MVA relative to 3-D guidance compared with Doppler pressure halftime and (n = 6) Gorlin areas. Phantom studies verified no differences in resolution for the 2 acquisition modes. Three-dimensional guidance reduced intraobserver variability from 9.8% to 3.8% (SEE 0.14 to 0.06 cm(2), p <0.01) and interobserver variability from 10.6% to 6.1% (SEE 0.15 to 0.09 cm(2), p <0.02). In conclusion, matrix-array technology provides a feasible and highly reproducible direct 3-D-guided method for measuring the limiting mitral orifice area.     

Reliability of the Doppler pressure half-time method for assessing effects of percutaneous mitral balloon valvuloplasty

The mitral valve areas determined by Doppler pressure half-time and by cardiac catheterization with use of the Gorlin formula were compared in 18 adult patients who underwent percutaneous mitral balloon valvuloplasty. Doppler measurements and catheterization were performed simultaneously before, immediately after and 24 to 48 h after valvuloplasty. A high correlation between Doppler- and catheterization-derived mitral valve areas was found before mitral valvuloplasty (r = 0.81, Y = 0.88X + 0.1, SEE = 0.11 cm2) and 24 to 48 h after valvuloplasty (r = 0.84, Y = 0.70X + 0.67, SEE = 0.20 cm2). In contrast, the correlation immediately after valvuloplasty was only moderate (r = 0.72, Y = 0.43X + 1.1, SEE = 0.49 cm2). The Doppler-derived mitral valve area (2.41 +/- 0.61 cm2) immediately after valvuloplasty was significantly larger than the catheterization-derived area (2.08 +/- 0.39 cm2, p less than 0.05). In conclusion, the Doppler echocardiographic measurement performed with the pressure half-time method may lead to significant error immediately after mitral balloon valvuloplasty, but clinically accurate measurement can be obtained 24 to 48 h after valvuloplasty.     

Quantification of tricuspid regurgitation by measuring the width of the vena contracta with Doppler color flow imaging: a clinical study

OBJECTIVE: We sought to evaluate the vena contracta width (VCW) measured using color Doppler as an index of severity of tricuspid regurgitation (TR). BACKGROUND: The VCW is a reliable measure of mitral and aortic regurgitation, but its value in measuring TR is uncertain. METHODS: In 71 consecutive patients with TR, the VCW was prospectively measured using color Doppler and compared with the results of the flow convergence method and hepatic venous flow, and its diagnostic value for severe TR was assessed. RESULTS: The VCW was 6.1+/-3.4 mm and was significantly higher in patients with, than those without, severe TR (9.6+/-2.9 vs. 4.2 +/- 1.6 mm, p<0.0001). The VCW correlated well with the effective regurgitant orifice (ERO) by the flow convergence method (r = 0.90, SEE = 0.17 cm2, p<0.0001), even when restricted to patients with eccentric jets (r = 0.93, p < 0.0001). The VCW also showed significant correlations with hepatic venous flow (r = 0.79, p < 0.0001), regurgitant volume (r = 0.77, p<0.0001) and right atrial area (r = 0.46, p< 0.0001). A VCW > or =6.5 mm identified severe TR with 88.5% sensitivity and 93.3% specificity. In comparison with jet area or jet/right atrial area ratio, the VCW showed better correlations with ERO (both p<0.01) and a larger area under the receiver operating characteristic curve (0.98 vs. 0.88 and 0.85, both p<0.02) for the diagnosis of severe TR. CONCLUSIONS: The VCW measured by color Doppler correlates closely with severity of TR. This quantitative method is simple, provides a high diagnostic value (superior to that of jet size) for severe TR and represents a useful tool for comprehensive, noninvasive quantitation of TR.     

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.     

A study of the correlation between Doppler and cposs-sectional echocardiography in the determination of mitral valve area

Fifty-five consecutive adult patients with mitral stenosis (MS)were in vestigatedby Doppler echocardiography, to assess theseverity of MS. The measurement of mitral valve area (MVA) bycross-sectional echocardiography (CSE) was considered as thereference method, because catheterization data are often inadequatewhen combined lesions are present. Doppler MVA was calculatedfrom apical mitral flow using the pressure half-time method. Adequate Doppler recordings (52 on 55) were easier to obtainthan adequate CSE images[47]. The correlation between both methodswas excellent (r = 0.90, SEE: 0.42 cm²) despite systematic underestimationof MVA by Doppler versus CSE. From our data, the following regressionequation could be drawn, providing MVA from Doppler measurements:MVA = 250 (pressure half-time)^–1 +0.15, where the areais in cm1 and half-time in ms. Both severe and mild MS wereidentified by Doppler with enough accuracy for clinical use.Reproducibility, inter and intraobserver variability were betterfor Doppler than for CSE. We conclude that Doppler seems particularly suitable for noninvasivequantification of MS and for patient follow-up.     

Effect of heart rate on transmitral flow velocity profile and Doppler measurements of mitral valve area in patients with mitral stenosis.

To study the effect of heart rate changes on Doppler measurements of mitral valve area atrial pacing was performed in 14 patients with mitral stenosis and sinus rhythm. Continuous wave Doppler and haemodynamic measurements were performed simultaneously at rest and during pacing-induced tachycardia. (1) Mitral valve area was determined using the conventional pressure half time method. (2) Additionally, mitral valve area was calculated with a combined Doppler and thermodilution technique according to the continuity equation. (3) Simultaneous invasive measurements were used for calculation of the mitral valve area according to the Gorlin formula. With increasing heart rate (69 +/- 13-97 +/- 15-114 +/- 13 beats min-1) mitral valve area either determined by the continuity equation (1.0 +/- 0.2-1.0 +/- 0.3-1.1 +/- 0.4 cm2) or the Gorlin formula (1.2 +/- 0.3-1.2 +/- 0.4-1.3 +/- 0.4 cm2) remained constant. Both methods correlated closely not only at rest (r = 0.88, SEE = 0.11 cm2, P less than 0.001), but also during atrial pacing (first level: r = 0.95, SEE = 0.10 cm2, P less than 0.001, second level: r = 0.95, SEE = 0.13 cm2, P less than 0.001). In contrast, mitral valve area calculated according to the pressure half time method increased significantly during atrial pacing (1.0 +/- 0.3-1.8 +/- 0.5-2.0 +/- 0.5 cm2).(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Effect of mitral regurgitation and volume loading on pressure half-time before and after balloon valvotomy in mitral stenosis

Doppler pressure half-time (PHT) is frequently used to assess mitral valve area (MVA), but the reliability of PHT has recently been challenged, specifically in the setting of balloon mitral valvotomy when hemodynamics have been abruptly altered. The effect of volume loading both before and after balloon mitral valvotomy on computation of MVA by Gorlin and by PHT in 18 patients with high-fidelity micromanometer measurements of left atrial and left ventricular pressure was therefore examined. Echocardiographic MVA increased from 0.91 +/- 0.15 to 1.97 +/- 0.42 cm2 after valvotomy. Volume loading produced significant increases in left atrial pressure (16 to 23 before and 12 to 20 mm Hg after valvotomy), in cardiac output (3.7 to 4.1 before and 3.9 to 4.6 liters/min after valvotomy), and in mitral valve gradient (11 to 14 before and 5 to 7 mm Hg after valvotomy). These hemodynamic changes were associated with modest but significant decreases in PHT and increases in MVA estimated by 220/PHT (0.66 to 0.81 before and 1.64 to 1.96 cm2 after valvotomy), whereas the MVA by Gorlin was not affected in a consistent fashion by volume loading (0.85 to 0.89 before and 1.66 to 1.69 cm2 after valvotomy). The correlation between Gorlin MVA and 220/PHT was only fair (r = 0.73, p less than 0.001) and was significantly poorer among patients with greater than 1+ mitral regurgitation (r = 0.72) than among those with less or no regurgitation (r = 0.79) (p = 0.001 by analysis of covariance for mitral regurgitation effect).(ABSTRACT TRUNCATED AT 250 WORDS)     

Two-dimensional transesophageal echocardiographic determination of aortic valve area in adults with aortic stenosis

To determine if aortic stenosis severity could be accurately measured by two-dimensional transesophageal echocardiography (TEE), 62 adult subjects (mean age 66 +/- 12 years) with aortic stenosis had their aortic valve area (AVA) determined by direct planimetry using TEE, and with the continuity equation using combined transthoracic Doppler and two-dimensional echocardiography (TTE). Eighteen subjects had AVA calculated by the Gorlin method during catheterization. An excellent correlation (r = 0.93, SEE = 0.17 cm2) was found between AVA determined by TEE (mean 1.24 +/- 0.49 cm2; range 0.40 to 2.26 cm2) and TTE (mean 1.23 +/- 0.46 cm2; range 0.40 to 2.23 cm2). The absolute (0.13 +/- 0.12 cm2) and percent (10.8 +/- 8.9%) differences between AVA determined by TEE versus TTE were small. Excellent correlations between AVA by TEE and TTE were also found in subjects with normal systolic function (r = 0.95, SEE = 0.14 cm2; n = 38) and impaired function (r = 0.91, SEE = 0.21 cm2; n = 24). AVA determined by catheterization correlated better with AVA measured by TEE (r = 0.91, SEE = 0.15 cm2) than AVA measured with TTE (r = 0.84, SEE = 0.19 cm2). These data demonstrate that AVA can be accurately measured by direct planimetry using TEE in subjects with aortic stenosis. TEE may become an important adjunct to transthoracic echocardiography in the assessment of aortic stenosis severity.     

Mitral valve hemodynamic effects of percutaneous edge-to-edge repair with the MitraClip device for mitral regurgitation.

INTRODUCTION: The Endovascular Valve Edge-to-Edge REpair STudies (EVEREST) are investigating a percutaneous technique for edge-to-edge mitral valve repair with a repositionable clip. The effects on the mitral valve gradient (MVG) and mitral valve area (MVA) are not known. METHODS: Twenty seven patients with moderate to severe or severe mitral regurgitation (MR) were enrolled. Echocardiography was performed preprocedure, at discharge, and at 1, 6, and 12 months. Mean MVG was measured by Doppler and MVA by planimetry and pressure half-time, and evaluated in a central core laboratory. Pre- and postclip deployment, simultaneous left atrial/pulmonary capillary wedge and left ventricular pressures were obtained in eight patients. RESULTS: Three patients did not receive a clip, six patients had their clip(s) explanted by 6 months (none for mitral stenosis), and four were repaired with two clips. Results are notable for a slight increase in mean MVG by Doppler postclip deployment (1.79 +/- 0.89 to 3.31 +/- 2.09 mm Hg, P < 0.01) and an expected decrease in MVA by planimetry (6.49 +/- 1.61 to 4.46 +/- 2.14 cm(2), P < 0.001) and by pressure half time (4.35 +/- 0.98 to 3.01 +/- 1.42 cm(2), P < 0.05). There were no significant changes in hemodynamic parameters postclip deployment by direct pressure measurements. There was no change in MVA by planimetry from discharge to 12 months (3.90 +/- 1.90 to 3.79 +/- 1.54 cm(2), P = 0.78). CONCLUSIONS: Echocardiographic and hemodynamic measurements after percutaneous mitral valve repair with the MitraClip show an expected decrease in mitral valve area with no evidence of clinically significant mitral stenosis either immediately after clip deployment or after 12 months of follow-up.     

Doppler sonography quantification of mitral valve stenosis in patients with and without mitral valve insufficiency

Fifty-three patients with mitral stenosis (MS) were examined by two dimensional (2DE) and Doppler echocardiography (Dop). Twenty-nine of them also had mitral insufficiency (MI) as judged by Dop. The mitral valve area (MVA) was calculated from Doppler using the "pressure half time" and was compared with MVA by 2 DE. There was a good correlation between both methods in all 53 patients (r = 0.88; SEE = 0.34 cm2) but also in the subgroups with pure MS (r = 0.86; SEE = 0.29 cm2) and MS + MI respectively (r = 0.90; SEE = 0.38 cm2). The accuracy and the reproducibility of the Doppler method was highly dependent on the severity of the stenosis. In 19 cases with mild MS (MVA by 2 DE greater than 1.5 cm2) the absolute difference between MVA 2 DE and Dop averaged 0.39 cm2. The difference between the maximal and minimal Doppler MVA which reflects the variability of this method averaged 0.65 cm2 in this group. In cases with significant MS (MVA by 2 DE less than or equal to 1.5 cm2) the average difference 2 DE -Dop and Dop max-Dop min was only 0.20 cm2 and 0.27 cm2 respectively. In patients with comparable degrees of stenosis additional MI did not adversely affect the accuracy of the Doppler method. We conclude that Doppler echo allows an accurate quantitation of mitral stenosis even in patients with associated MI.     

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)     

Assessment of Mitral Regurgitation by the Measurement of Vena Contracta Using Power Doppler Echocardiography

The measurement of vena contracta is a promising method for quantification of mitral regurgitation (MR). No data exist regarding the ability of power Doppler echocardiography in the assessment of vena contracta in MR. We attempted to clarify the ability of power Doppler in the assessment of vena contracta in MR. The width of vena contracta was measured using power Doppler in 70 patients with chronic MR. Mean effective regurgitant orifice area (EROA) was calculated quantitatively by the spectral Doppler. The area of vena contracta was calculated by measuring the width of vena contracta from the following formula: Vena contracta area = * (vena contracta width/2)². The width of vena contracta ranged from 3.6 to 8.4 mm. The EROA varied from 0.10 to 0.56 cm². Good correlations were found between EROA and vena contracta area obtained by power Doppler (r = .95, p < .0001, SEE = 0.04 cm²). Strong relationships were observed between the area of vena contracta and regurgitant volume (r = 0.93, p < .0001, SEE = 8.1 ml/beat), and regurgitant fraction (r = 0.95, SEE = 6.1%). Power Doppler may provide an additional method for assessing vena contracta in MR. Abbreviations: MR = mitral regurgitation; LV = left ventricle; TVI = time-velocity integral; EROA = effective regurgitant orifice area     

Determination of vena contracta and its value in evaluating severity of aortic regurgitation

BACKGROUND AND AIMS OF THE STUDY: Recent studies evaluating the severity of valvular insufficiencies have focused on the effective regurgitant orifice area (EROA), which corresponds hydrodynamically to the cross-sectional area of the vena contracta (VC). The study aim was to quantify aortic regurgitation (AR) by using color Doppler imaging of the VC. METHODS: Fifty-five patients with chronic AR were enrolled into the study. VC was visualized by transthoracic echocardiography from the apical echocardiographic window. The quantitative Doppler (QD) method, depending on mitral and aortic stroke volumes, was taken as a reference method. EROA, regurgitant volume (RV) and regurgitant fraction (RF) were calculated using both VC and QD simultaneously in all patients, and the results obtained with each method were compared. RESULTS: EROA(QD) (r = 0.96), RFQD (r = 0.84), RVQD (r = 0.82), and AR grade 3+ or 4+ (r = 0.74) were statistically significantly correlated with VC (4.8+/-1.2 mm). In the multivariate analysis, VC was related only to EROA(QD). The EROA (r = 0.96, p <0.001; mean difference 0+/-0.03 cm2, SEE = 0.004 and p >0.05), RV (r = 0.97, p <0.001; mean difference =1.3+/-4.8 cm3, SEE = 0.65 cm3 and p >0.05) and RF (r = 0.93, p <0.001; mean difference = 1.46+/-4.9%, SEE = 0.66% and p >0.05) obtained by both methods agreed well with each other. VC had a sensitivity of 80%, a specificity of 86%, and an accuracy of 84% in determining severe AR for VC > or =5.5 mm. CONCLUSION: The vena contracta can be visualized using a transthoracic approach from the apical window. The severity of AR can be evaluated using the VC width itself, and also in combination with Doppler data.     

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.     

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.