Assessment of mitral regurgitation severity by Doppler color flow mapping of the vena contracta

BACKGROUND: Although Doppler color flow mapping is widely used to assess the severity of mitral regurgitation (MR), a simple, accurate, and quantitative marker of MR by color flow mapping remains elusive. We hypothesized that vena contracta width by color flow mapping would accurately predict the severity of MR. METHODS AND RESULTS: We studied 80 patients with MR. Vena contracta width was measured in multiple views with zoom mode and nonstandard angulation to optimize its visualization. Flow volumes across the left ventricular outflow tract and mitral annulus were calculated by pulsed-Doppler technique to determine regurgitant volume. Effective regurgitant orifice area was calculated by dividing the regurgitant volume by the continuous-wave Doppler velocity-time integral of the MR jet. The cause of MR was ischemia in 24, dilated cardiomyopathy in 34 mitral valve prolapse in 12, endocarditis in 2, rheumatic disease in 2, mitral annular calcification in 1, and uncertain in 5. Regurgitant volumes ranged from 2 to 191 mL. Regurgitant orifice area ranged from 0.01 to 1.47 cm2. Single-plane vena contracta width from the parasternal long-axis view correlated well with regurgitant volume (r = .85, SEE = 20 mL) and regurgitant orifice area (r = .86, SEE = 0.15 cm2). Biplane vena contracta width from apical views correlated well with regurgitant volume (r = .85, SEE = 19 mL) and regurgitant orifice area (r = .88, SEE = 0.14 cm2). A biplane vena contracta width > or = 0.5 cm was always associated with a regurgitant volume > 60 mL and a regurgitant orifice area > 0.4 cm2. A biplane vena contracta width < or = 0.3 cm predicted a regurgitant volume < 60 mL and a regurgitant orifice area < 0.4 cm2 in 24 of 29 patients. No other parameter, including jet area, left atrial size, pulmonary flow reversal, or semiquantitative MR grade, correlated significantly with regurgitant volume or regurgitant orifice area in a multivariate analysis. CONCLUSIONS: Our results demonstrate that careful color flow mapping of the vena contracta of the MR jet provides a simple quantitative assessment of MR that correlates well with quantitative Doppler techniques.     

Clinical usefulness of the effective regurgitant orifice area determined by transesophageal echocardiography in patients with eccentric aortic regurgitation

BACKGROUND AND AIMS OF THE STUDY: The aortic regurgitant jet is frequently eccentric, and Doppler color flow mapping techniques of the distal jet is influenced by this eccentricity. The aim of the present study was to determine whether the effective regurgitant orifice area (EROA), determined by the proximal isovelocity surface area (PISA) method using multiplane transesophageal echocardiography (m-TEE), could be used to evaluate the severity of aortic regurgitation (AR) in patients with an eccentric jet. METHODS: Forty-eight patients with eccentric AR were studied. Values of EROA determined by the PISA method were compared with results from cross-sectional area (CSA), vena contracta (VC) width, aortic angiography, and regurgitant fraction. RESULTS: Values of EROA correlated well with results from CSA (r = 0.73, p < 0.001), VC (r = 0.74, p < 0.001), angiographic grade (rs = 0.90 p < 0.001), and regurgitant fraction (r = 0.84, p < 0.001) in patients with eccentric aortic regurgitation. Values of EROA > 0.27 cm2 were always associated with a regurgitant fraction > 0.4, while EROA values < 0.27 cm2 were always associated with a regurgitant fraction < 0.4. CONCLUSIONS: We conclude that, in patients with an eccentric jet, measurement of EROA values by the PISA method using m-TEE is a reliable method of assessing the severity of AR.     

Color Doppler regurgitant jet area for evaluating eccentric mitral regurgitation: an animal study with quantified mitral regurgitation

OBJECTIVES: The purpose of the present study was to rigorously evaluate the accuracy of the color Doppler jet area planimetry method for quantifying chronic mitral regurgitation. BACKGROUND: Although the color Doppler jet area has been widely used clinically for evaluating the severity of mitral regurgitation, there have been no studies comparing the color jet area with a strictly quantifiable reference standard for determining regurgitant volume. METHODS: In six sheep with surgically produced chronic mitral regurgitation, 24 hemodynamically different states were obtained. Maximal color Doppler jet area for each state was obtained with a Vingmed 750. Image data were directly transferred in digital format to a microcomputer. Mitral regurgitation was quantified by the peak and mean regurgitant flow rates, regurgitant stroke volumes and regurgitant fractions determined using mitral and aortic electromagnetic flow probes. RESULTS: Mean regurgitant volumes varied from 0.19 to 2.4 liters/min (mean [+/- SD] 1.2 +/- 0.59), regurgitant stroke volumes from 1.8 to 29 ml/beat (mean 11 +/- 6.2), peak regurgitant volumes from 1.0 to 8.1 liters/min (mean 3.5 +/- 2.1) and regurgitant fractions from 8.0% to 54% (mean 29 +/- 12%). Twenty-two of 24 jets were eccentric. Simple linear regression analysis between maximal color jet areas and peak and mean regurgitant flow rates, regurgitant stroke volumes and regurgitant fractions showed correlation, with r = 0.68 (SEE 0.64 cm2), r = 0.63 (SEE 0.67 cm2), r = 0.63 (SEE 0.67 cm2) and r = 0.58 (SEE 0.71 cm2), respectively. Univariate regression comparing regurgitant jet area with cardiac output, stroke volume, systolic left ventricular pressure, pressure gradient, left ventricular/left atrial pressure gradient, left atrial mean pressure, left atrial v wave pressure, systemic vascular resistance and maximal jet velocity showed poor correlation (0.08 < r < 0.53, SEE > 0.76 cm2). CONCLUSIONS: This study demonstrates that color Doppler jet area has limited use for evaluating the severity of mitral regurgitation with eccentric jets.     

Transesophageal Doppler echocardiography assessment of mitral valve insufficiency: Comparison of jet area, pulmonary venous flow profile, proximal jet diameter, maximal regurgitation flow rate and regurgitation orifice area with angiography

In transesophageal echocardiography several methods have been used to grade mitral regurgitation. For a direct comparison of these techniques, 36 patients (60 +/- 13 years) with native mitral regurgitation underwent multiplane transesophageal echocardiography and angiography within 5 days. We compared the following measurements: 1) The maximal color jet area of mitral regurgitation, 2) the ratio of maximal systolic to diastolic pulmonary venous flow velocity in the left upper pulmonary vein, 3) the proximal jet width of mitral regurgitation, 4) the maximal regurgitant flow rate Qmax, measured by the proximal convergence method, 5) the regurgitant office area Areg, calculated by dividing Qmax by maximal regurgitant velocity obtained by continuous wave Doppler. RESULTS: The correlation between color jet area (r = 0.4; p < 0.05) or pulmonary venous flow (r = -0.3; p = n.s.) with angiographic severity of mitral regurgitation is low. The sensitivity of the retrospective best cut-off values is 69% (color jet area) and 83% (pulmonary venous flow). Using retrospective best cut-off values all patients with mitral regurgitation Sellers grade III and IV are correctly identified by a proximal jet width > or = 0.7 cm, Qmax > or = 300 ml/s or a Areg > or = 0.5 cm2 (sensitivity and specificity of 83-100%). Spearman's rank coefficient demonstrated a high correlation (r = 0.75-0.77; p < 0.001) between proximal jet width, Qmax and Areg and with angiographic severity. CONCLUSION: Multiplane transesophageal echocardiographic grading of mitral regurgitation by proximal jet width or proximal convergence zone shows comparably good results and is clearly superior to grading by color jet area or pulmonary venous flow, if adequate image quality is achieved.     

Color flow imaging compared with quantitative Doppler assessment of severity of mitral regurgitation: influence of eccentricity of jet and mechanism of regurgitation

OBJECTIVES: To determine the influence of jet eccentricity and mechanism of mitral regurgitation, we examined 1) the relation between jet extent and severity of mitral regurgitation, and 2) the use of Doppler color flow imaging for quantitation of mitral regurgitation. BACKGROUND: Doppler color flow imaging is widely used to assess mitral regurgitation. However, whether, how and in which subgroups it can quantify regurgitation remain controversial. METHODS: In 80 patients with mitral regurgitation, results of color flow Doppler studies obtained in two orthogonal apical views were prospectively compared with quantitative Doppler measurement of the regurgitant volume and the regurgitant fraction. Comparisons were made according to the eccentricity of the jet (group 1 eccentric jets, n = 29; group 2 central jets, n = 51); group 2 was subdivided according to the mechanism of mitral regurgitation (group 2a organic, n = 27; group 2b ischemic or functional, n = 24). RESULTS: Globally, weak correlations were found between regurgitant volume and jet area (r = 0.57) and regurgitant fraction and jet area/left atrial area ratio (r = 0.65). Groups 1 and 2 showed a correlation between regurgitant volume and jet area (r = 0.68 and r = 0.65, respectively, p < 0.0001), but the slope was steeper in group 2 than in group 1 (0.22 vs. 0.06, p < 0.0001). The same jet area corresponded to more severe regurgitation in group 1 than in group 2 (jet > or = 8 cm2, regurgitant volume 113 +/- 55 vs. 43 +/- 21 ml, p < 0.0001). Similarly, for comparable regurgitant volumes (24 +/- 22 vs. 29 +/- 11 ml, p = NS), group 2a had a smaller jet area than did group 2b (5.3 +/- 6 vs. 9.6 +/- 6 cm2, p < 0.02). Quantitation of regurgitation by Doppler color flow imaging was unreliable in group 1; in group 2b, the regression line between regurgitant fraction and jet area/left atrial area ratio was close to the identity line. CONCLUSIONS: Mitral regurgitant jet eccentricity and mechanism influence jet extent. The same regurgitant volume produces smaller jet areas for eccentric compared with central jets and for central organic compared with ischemic or functional regurgitation. Quantitation of regurgitation using Doppler color flow imaging is possible in ischemic or functional regurgitation but inappropriate in eccentric jets, where quantitative Doppler study should be recommended.     

Comparison of transesophageal Doppler methods with angiography for evaluation of the severity of mitral regurgitation

Doppler evaluation of mitral regurgitation remains difficult; thus, a head-to-head comparison of the diagnostic accuracy of Doppler methods was undertaken. Fifty patients with native mitral regurgitation underwent multiplane transesophageal echocardiography within 5 days of catheterization. Angiographic grade of mitral regurgitation and, in 20 patients with grade II-IV regurgitation, invasively determined regurgitant stroke volume were compared with color Doppler area, regurgitant jet diameter, ratio of systolic to diastolic peak pulmonary venous flow velocities, and (based on the proximal convergence zone) maximal regurgitant flow rate and regurgitant orifice area. Rank correlation coefficients of angiographic grade with Doppler parameters were 0.61 for color jet area, -0.61 for pulmonary venous flow velocity ratio, 0.69 for color jet diameter, 0.79 for maximal regurgitant flow rate, and 0.78 for regurgitant orifice area (all P < .01). Convergence zone-based parameters also correlated best (r=0.73) with invasively determined regurgitant stroke volume. Receiver operating characteristic curve analysis confirmed higher diagnostic accuracy for proximal jet width and proximal convergence zone parameters than for color jet area or pulmonary venous flow velocity ratio. Proximal convergence zone parameters and proximal color jet diameter best distinguished severe from mild forms of mitral regurgitation.     

An integrated approach to the quantification of aortic regurgitation by Doppler echocardiography

BACKGROUND: Although different Doppler methods have been proposed for the quantification of aortic regurgitation, no study has prospectively compared these methods with each other and their correlation with angiography. The aim of this study was to prospectively analyze the usefulness of different Doppler echocardiography parameters by testing all such parameters in each patient. METHODS: Fifty-one patients with aortic regurgitation underwent 2-dimensional and Doppler echocardiographic studies and catheterization. The following Doppler indexes were analyzed and compared with aortography. Color Doppler: (1) jet color height/left ventricular outflow tract height in parasternal long-axis view, and (2) jet color area/left ventricular outflow tract area in short-axis view. Continuous Doppler: (3) regurgitant flow pressure half-time, (4) regurgitant flow time velocity integral (in centimeters), and (5) regurgitant flow time velocity integral (in centimeters)/diastolic period (in milliseconds). Pulsed Doppler in thoracic and abdominal aorta: (6) time velocity integral of diastolic reverse flow (in centimeters), (7) time velocity integral of systolic anterograde flow/integral of diastolic reverse flow, (8) (time velocity integral of diastolic reverse flow/diastolic period) x 100, and (9) diastolic reverse flow duration/diastolic period (as a percentage). We compared these parameters with severity of regurgitation measured by angiography and classified as mild, moderate, or severe. RESULTS: The most useful parameters were (1) jet color height/left ventricular outflow tract height (correctly classified 42 of 49 patients), (2) (time velocity integral of diastolic reverse flow/diastolic period) x 100 in the thoracic aorta (correctly classified 41 of 46 patients), and (3) (time velocity integral of diastolic reverse flow/diastolic period) x 100 in the abdominal aorta (correctly classified 42 of 49 patients). Sequential integration of these 3 parameters correctly classified 96% of patients (44 of 46 patients) and was achieved in 90% of cases. CONCLUSION: An integrated combination of several Doppler parameters can quickly and accurately classify the degree of aortic regurgitation as determined by angiography.     

Flow reversal in the descending aorta: a guide to intraoperative assessment of aortic regurgitation with transesophageal echocardiography

This study assessed the value of biplane transesophageal echocardiographic assessment of diastolic flow reversal in the descending aorta as an alternative to Doppler color flow imaging in determining severity of aortic regurgitation. In 45 patients undergoing cardiac operations, the severity of aortic regurgitation was assessed by semiquantitative grading of the width of the Doppler color flow regurgitant jet relative to the left ventricular outflow tract, and the presence of diastolic flow reversal was assessed with pulsed-wave Doppler measurements at three sites in the descending aorta. In four patients, the diastolic flow reversal method was the only available form of assessment because of inadequate visualization of the left ventricular outflow tract beneath a mitral valve prosthesis. Diastolic flow reversal in the descending aorta was not observed in patients without aortic regurgitation and was always present in patients with severe aortic regurgitation. Aortic valve replacement successfully eliminated descending aortic flow reversal in all 19 patients in whom it was present before valve replacement. Identification of diastolic flow reversal at multiple sites in the descending aorta with biplane transesophageal echocardiography helps to confirm the presence of severe aortic regurgitation and can serve as an alternative method of assessment when visualization of the left ventricular outflow tract is impaired.     

Quantification of mitral regurgitation by velocity-encoded cine nuclear magnetic resonance imaging

OBJECTIVES: The feasibility of velocity-encoded cine nuclear magnetic resonance (NMR) imaging to measure regurgitant volume and regurgitant fraction in patients with mitral regurgitation was evaluated. BACKGROUND: Velocity-encoded cine NMR imaging has been reported to provide accurate measurement of the volume of blood flow in the ascending aorta and through the mitral annulus. Therefore, we hypothesized that the difference between mitral inflow and aortic systolic flow provides the regurgitant volume in the setting of mitral regurgitation. METHODS: Using velocity-encoded cine NMR imaging at a magnet field strength of 1.5 T and color Doppler echocardiography, 19 patients with isolated mitral regurgitation and 10 normal subjects were studied. Velocity-encoded cine NMR images were acquired in the short-axis plane of the ascending aorta and from the short-axis plane of the left ventricle at the level of the mitral annulus. Two independent observers measured the ascending aortic flow volume and left ventricular inflow volume to calculate the regurgitant volume as the difference between left ventricular inflow volume and aortic flow volume, and the regurgitant fraction was calculated. Using accepted criteria of color flow Doppler imaging and spectral analysis, the severity of mitral regurgitation was qualitatively graded as mild, moderate or severe and compared with regurgitant volume and regurgitant fraction, as determined by velocity-encoded cine NMR imaging. RESULTS: In normal subjects the regurgitant volume was -6 +/- 345 ml/min (mean +/- SD). In patients with mild, moderate and severe mitral regurgitation, the regurgitant volume was 156 +/- 203, 1,384 +/- 437 and 4,763 +/- 2,449 ml/min, respectively. In normal subjects the regurgitant fraction was 0.7 +/- 6.1%. In patients with mild, moderate and severe mitral regurgitation, the regurgitant fraction was 3.1 +/- 3.4%, 24.5 +/- 8.9% and 48.6 +/- 7.6%, respectively. The regurgitant fraction correlated well with the echocardiographic severity of mitral regurgitation (r = 0.87). Interobserver reproducibilities for regurgitant volume and regurgitant fraction were excellent (r = 0.99, SEE = 238 ml; r = 0.98, SEE = 4.1%, respectively). CONCLUSIONS: These findings suggest that velocity-encoded NMR imaging can be used to estimate regurgitant volume and regurgitant fraction in patients with mitral regurgitation and can discriminate patients with moderate or severe mitral regurgitation from normal subjects and patients with mild regurgitation. It may be useful for monitoring the effect of therapy intended to reduce the severity of mitral regurgitation.     

Transesophageal echocardiography in mitral prosthesis dysfunction: usefulness and limitations in the evaluation of mitral insufficiency

This study was performed to test the usefulness of transesophageal echocardiography in the diagnosis and assessment of pathological mitral regurgitation in patients with mitral valve prostheses. Doppler color flow imaging by transesophageal echocardiography was compared to the transthoracic echocardiography and angiographic and surgical assessment. We analyzed the influence of the spatial configuration of the jet on the semiquantitative assessment of mitral regurgitation. We studied 71 patients with prostheses in mitral position which were submitted for transesophageal echocardiography examination. 51 of these patients were found to have a pathological prosthetic regurgitation that was confirmed in 21 cases by left ventriculography and in 4 during cardiac surgery. Transesophageal echocardiography Doppler color flow imaging identified a regurgitant jet in 31 patients (60.7%). There was complete agreement with the quantitative assessment of regurgitation by angiography or surgery in 36% of the cases. All patients with prosthetic insufficiency observed by angiography or during cardiac surgery were confirmed by transesophageal echocardiography. Complete agreement in grade of severity by transthoracic echocardiography was found in 84% of cases. There was a difference in grade of severity of mitral regurgitation in only 4 patients. Regurgitant jets were classified by transesophageal echocardiography color Doppler in two groups: free jets and impinging wall jets. 21 cases presented a free jet and 31 excentrically directed impinging wall jet of mitral regurgitation. There was complete agreement with hemodynamic assessment of severity in all patients with regurgitant free jets (11/11). In presence of jet wall there was understimation of mitral regurgitation in 28.5% (4/13).(ABSTRACT TRUNCATED AT 250 WORDS)     

Long-term test-retest reliability of personality disorder diagnoses in opiate dependent patients

Continuous wave Doppler methods have been widely used clinically for evaluating the severity of aortic regurgitation; however, there have been no studies comparing these continuous wave Doppler methods with a strictly quantifiable reference for regurgitant severity. The purpose of this study was to test the applicability of continuous wave Doppler methods (deceleration slope and pressure half-time) for evaluation of chronic aortic regurgitation in an animal model. Eight sheep were studied 8 to 20 weeks after surgery to create chronic aortic regurgitation. Twenty-nine hemodynamically different states were obtained pharmacologically. A Vingmed 775 system was used for recording continuous wave Doppler traces with a 5 MHz annular array transducer directly placed on the heart near the apex. The aortic regurgitation was quantified as peak and mean regurgitant flow rates, regurgitant stroke volumes and regurgitant fractions determined with pulmonary and aortic electromagnetic flow probes and meters balanced against each other. Peak regurgitant flow rates varied from 1.8 to 13.6 L/min (6.3 +/- 3.2 L/min) (mean +/- SD), mean regurgitant flow rates varied from 0.7 to 4.9 L/min (2.7 +/- 1.3 L/min), regurgitant stroke volume varied from 7.0 to 48.0 ml/beat (26.9 +/- 12.2 ml/beat), and regurgitant fraction varied from 23% to 78% (53% +/- 16%). Only marginal correlations were obtained between reference indexes and continuous wave Doppler deceleration slope and pressure half-time (r = 0.55 to 0.74). A deceleration slope greater than 3 m/sec2 and pressure half-time less than 400 msec did, however, provide 100% specificity for detecting severe AR (regurgitant fraction > 50%). Our study shows that the continuous wave Doppler deceleration slope and pressure half-time methods have limited use for quantifying aortic regurgitation.     

Noninvasive estimation of regurgitant flow rate and volume in patients with mitral regurgitation by Doppler color mapping of accelerating flow field

OBJECTIVES: This study was designed to examine the accuracy of proximal accelerating flow calculations in estimating regurgitant flow rate or volume in patients with different types of mitral valve disease. BACKGROUND: Flow acceleration proximal to a regurgitant orifice, observed with Doppler color flow mapping, is constituted by isovelocity surfaces centered at the orifice. By conservation of mass, the flow rate through each isovelocity surface equals the flow rate through the regurgitant orifice. METHODS: Forty-six adults with mitral regurgitation of angiographic grades I to IV were studied. The proximal accelerating flow rate (Q) was calculated by: Q = 2 pi r2.Vn, where pi r2 is the area of the hemisphere and Vn is the Nyquist velocity. Radius of the hemisphere (r) was measured from two-dimensional or M-mode Doppler color recording. From the M-mode color study, integration of accelerating flow rate throughout systole yielded stroke accelerating flow volume and mean flow rate. Mitral regurgitant flow rate and stroke regurgitant volume were measured by using a combination of pulsed wave Doppler and two-dimensional echocardiographic measurements of aortic forward flow and mitral inflow. RESULTS: The proximal accelerating flow region was observed in 42 of 46 patients. Maximal accelerating flow measured from either two-dimensional (372 +/- 389 ml/s) or M-mode (406 +/- 421 ml/s) Doppler color study tended to overestimate the mean regurgitant flow rate (306 +/- 253 ml/s, p < 0.05). Mean Doppler accelerating flow rate correlated well with mean regurgitant flow rate (r = 0.95, p < 0.001), although there was a tendency toward slight overestimation of mean regurgitant flow by mean accelerating flow in severe mitral regurgitation. However, there was no significant difference between the mean accelerating flow rate (318 +/- 304 ml/s) and the mean regurgitant flow rate (306 +/- 253 ml/s, p = NS) for all patients. A similar relation was found between accelerating flow stroke volume (78.27 +/- 62.72 ml) and regurgitant flow stroke volume (76.06 +/- 59.76 ml) (r = 0.95, p < 0.001). The etiology of mitral regurgitation did not appear to affect the relation between accelerating flow and regurgitant flow. CONCLUSIONS: Proximal accelerating flow rate calculated by the hemispheric model of the isovelocity surface was applicable and accurate in most patients with mitral regurgitation of a variety of causes. There was slight overestimation of regurgitant flow rate by accelerating flow rate when the regurgitant lesion was more severe.     

Factors influencing pulmonary venous flow velocity patterns in mitral regurgitation: an in vitro study

OBJECTIVES: The aim of this study was to investigate factors affecting pulmonary venous flow patterns in mitral regurgitation. BACKGROUND: Although pulmonary venous flow velocity patterns have been reported to be helpful in assessing the severity of mitral regurgitation, the influence of regurgitant jet direction, pulmonary venous location and left atrial pressures on pulmonary venous flow patterns has yet to be clarified. METHODS: The mitral regurgitant jet was produced by a pulsatile piston pump at 10, 30 and 40 ml/beat through a circular orifice, whereas the pulmonary venous flow was driven by gravity. Four different patterns of pulmonary venous flow and mitral regurgitation were examined. The V wave pressure was set at 10, 30 and 50 mm Hg and pulmonary venous flow velocity at 30 cm/s. Color and pulsed Doppler recordings were obtained with a VingMed 800 scanner interfaced with a computer facilitating digital analysis. RESULTS: The decrease in the velocity time integral of pulmonary venous flow was more prominent for any given volume of mitral regurgitation at higher left atrial pressure. When the mitral regurgitant jet was directed toward the pulmonary vein, a more prominent decrease in the velocity time integral was seen, especially for severe mitral regurgitation (40 ml) with high left atrial pressure (95% vs. 55%, p < 0.001); and the time to peak deceleration of forward flow was significantly shorter (485 vs. 523 ms, respectively, p < 0.01). Also, two different types (laminar and turbulent) of reversed pulmonary venous flow were observed. CONCLUSIONS: Multiple factors, including jet direction, mitral regurgitant volume and left atrial pressure, determine the effect of mitral regurgitation on pulmonary venous flow velocity patterns.     

Overestimation of severity of ischemic/functional mitral regurgitation by color Doppler jet area

Color Doppler jet analysis is widely used to characterize the degree of mitral regurgitation (MR), but the validity of this approach in patients with ischemic or functional MR has not been established. It was hypothesized that color Doppler jet area overestimates the magnitude of MR of ischemic or functional origin. The severity of isolated MR in 170 patients was measured by using Doppler/echocardiography. Group 1 (n = 58) included patients with ischemic or functional MR, and group 2 (n = 112) included those with organic MR. The regurgitant jet area and 2 methods of quantitation (quantitative Doppler and quantitative 2-dimensional echocardiography) were measured simultaneously. In group 1, color jet area was larger (10.6 +/- 5.3 vs 8.2 +/- 5.3 cm2, p = 0.004) but corresponded to a smaller regurgitant volume and regurgitant fraction by quantitative Doppler (28 +/- 14 vs 55 +/- 46 ml, p = 0.0006, and 31 +/- 12% vs 38 +/- 20%, p = 0.02, respectively) and by quantitative 2-dimensional echocardiography (22 +/- 11 vs 49 +/- 40 ml, p < 0.0001, and 27 +/- 12% vs 36 +/- 20%, p = 0.005, respectively). Enlargement of the left-sided chambers was more marked in group 1. In ischemic/functional MR, the diagnosis of severe regurgitation by color Doppler (jet area > 8 cm2) was confirmed by quantitative methods (regurgitant fraction > or = 50%) in only 6% to 11% of patients, whereas it was confirmed in 60% to 73% of patients with organic MR (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

A transesophageal color-coded pulsed Doppler echocardiographic study of the spatial distribution of mitral regurgitation jets

OBJECTIVE: Transesophageal echocardiographic analysis of color Doppler characteristics of mitral valvular regurgitation jets. DESIGN: Transesophageal echocardiographic prospective study. SETTING: Ambulatory patients referred to Echocardiographic Laboratory of Gregorio Mara?on General Hospital, Madrid, Spain. MATERIAL AND METHODS: We studied a group of 100 consecutive patients with mitral regurgitation diagnosis. In each patient we calculated the degree of severity, percentage of wall intersection, maximal traced area, axis direction, atrial depth, maximal transversal diameter, perimeter and angle of the mitral regurgitation jet. We divided the entire population in three different groups according to the jet direction in central (CJ), eccentric (EJ) and wall jets (WJ). MAIN RESULTS: The direction of the mitral regurgitation jet was central in 49%, eccentric in 33% and impinging the left atrial wall in 18%. The mitral regurgitation jet angle was in the CJ 80 +/- 11 degrees, EJ 33 +/- 10 degrees and WJ 6 +/- 7 degrees. Maximal mitral regurgitant traced area in CJ was 732 +/- 104 mm2, EJ was 593 +/- 110 mm2 and WJ was 267 +/- 80 mm2. Maximal regurgitant jet depth in CJ was 36 +/- 17 mm, EJ 30 +/- 15 mm and WJ 49 +/- 14 mm. The perimeter of the mitral regurgitation jet in the CJ was 87 +/- 22 mm, EJ was 68 +/- 22 mm and WJ was 92 +/- 30 mm. CONCLUSIONS: Color Doppler quantification criteria are not useful in all patients with mitral regurgitation jets. The presence of atrial walls close to the mitral regurgitation jet area is an important factor in the mitral regurgitation color Doppler evaluation.     

Automated assessment of mitral regurgitant volume and regurgitant fraction by a newly developed digital color Doppler velocity profile integration method

Recent development of the automated cardiac flow measurement (ACFM) method has provided automated measurement of stroke volume and cardiac output by spatial and temporal integration of digital Doppler velocity profile data. The purpose of this study was to evaluate the clinical usefulness of the ACFM method using digital color Doppler velocity profile integration in the assessment of mitral regurgitant volume and regurgitant fraction from measurements of both aortic outflow and mitral inflow volumes. We calculated both aortic outflow and mitral inflow volumes from the apical approach with the ACFM and pulsed Doppler (PD) methods in 20 patients with isolated mitral regurgitation. Mitral regurgitant volume and regurgitant fraction were calculated by the following equation: mitral regurgitant volume = (mitral inflow volume) - (aortic outflow volume), % regurgitant fraction = (mitral regurgitant volume)/(mitral inflow volume) x 100. Mitral regurgitant volume and regurgitant fraction were compared with that determined by the PD method. Mitral regurgitant volume measurement by the ACFM method showed a good correlation with that measured by the PD method (r = 0.90, y = 0.77x + 11.6, SEE = 9.0 ml); the mean differences between PD and ACFM measurements was -1.7 +/- 12.5 ml. Regurgitant fraction estimated by the ACFM method correlated well with that of the PD method (r = 0.92, y = 0.98x + 2.1, SEE = 8.8%). The mean difference for the measurement of regurgitant fraction between the PD and ACFM methods was 0.8 +/- 6.6%. Total time required for mitral regurgitant volume calculation in 1 cardiac cycle by the ACFM method was significantly shorter than that of the PD method (126 +/- 15 seconds vs 228 +/- 36 seconds, p <0.01). In conclusion, the newly developed ACFM method is simple, quick, and accurate in the automated assessment of mitral regurgitant volume and regurgitant fraction.     

Evaluation of tricuspid regurgitation by the ultrasonic pulsed Doppler technique from a transcutaneous approach (author's transl)

Severity of tricuspid regurgitation was assessed by using a combined system of the ultrasonic pulsed Doppler technique and two-dimensional echocardiography from a transcutaneous approach. The study group comprised 47 patients with various heart diseases, who were clinically presumed to have tricuspid regurgitation, and 10 healthy subjects. 1) Pansystolic abnormal flow signal was detected in an area from the tricuspid valve into the right atrial cavity in 43 patients including 8 patients without definitive signs of tricuspid regurgitation. Such abnormal flow had never been detected in healthy subjects and was considered to represent tricuspid regurgitant flow. Tricuspid regurgitant flow usually exhibited a wide band spectrum of velocity component indicating a disturbed flow. In 4 patients with clinical signs of severe tricuspid regurgitation, a laminar flow was detected in the right atrial cavity, which was considered to indicate a regurgitant jet in the central part of tricuspid regurgitant flow. 2) The area where tricuspid regurgitant flow was detected was interpreted as revealing the main direction and spread of tricuspid regurgitant flow. Based on this finding, severity of TR was classified into 4 grades by the assessment on the basis of the distance reached by tricuspid regurgitant flow in the right atrium. Severity of tricuspid regurgitation was also classified into 4 grades by right ventriculography. The grade of tricuspid regurgitation assessed by Doppler technique was nearly consistent with that assessed by right ventriculography. Severity of tricuspid regurgitation was also classified into 4 grades on the basis of the extent of the area where the regurgitant flow spread, and nearly the same results were obtained as those described above. 3) Thus, the combined use of Doppler flowmetry and two-dimensional echocardiography proved to be useful for detecting tricuspid regurgitant flow and assessing the severity of tricuspid regurgitation.     

Effect of transcriptional regulatory sequences on autonomous replication of plasmids in transient mammalian systems

BACKGROUND AND AIMS OF THE STUDY: Most studies on mitral regurgitation have focused on evaluating the regurgitant volume. The effects of mitral regurgitation and its associated cardiac workload on left ventricular function and mechanics may be equally important both in assessing the impact of regurgitation as well as in planning and evaluating therapy. The present study was undertaken to investigate the interrelationships of the regurgitant volume, hemodynamics and left ventricular work in an experimental animal model of chronic mitral regurgitation in which the regurgitant volume could be measured directly with electromagnetic flow probes. METHODS: A total of 21 hemodynamic states were studied in six sheep with surgically created mitral regurgitation. Regurgitant flow rates were obtained from electromagnetic flow meters. Left ventricular and atrial pressures were recorded using high-fidelity catheters. Regurgitant jet velocity was recorded by continuous wave Doppler. Left ventricular stroke work and energy losses due to the regurgitation were calculated. RESULTS: There was a close correlation between left ventricular stroke work and both jet energy and left atrial systolic pressure rise (r = 0.81, p = 0.0001 and r = 0.92, p = 0.0001, respectively). A moderate correlation to the regurgitant volume was found (r = 0.52, p = 0.01). CONCLUSIONS: The regurgitant volume itself is only one of the determinants of left ventricular stroke work in mitral regurgitation. Other factors such as left atrial mechanical properties and the regurgitant kinetic jet energy are at least as important for assessing cardiac work in patients with mitral regurgitation.     

Enhancement of Doppler signals in aortic and mitral valve diseases

Ultrasound contrast media increase backscatter from blood, thus improving the signal-to-noise ratio. Potential clinical applications of intravenous ultrasound contrast are reviewed. Contrast enhancement of continuous wave Doppler is indicated when the native recordings are noisy and no complete envelope of the Doppler spectrum is obtained. In aortic stenosis several investigations showed good agreement between the gradient calculated from Doppler measurements and the results of cardiac catheterization. In mitral insufficiency maximum area of the regurgitant jet is a widely used parameter for estimation of the severity of the regurgitation. However, assessment of the maximum jet area may not be possible because of poor acoustic windows. Contrast enhancement provides complete display of the regurgitant jet in most of the patients. The diagnostic confidence of the Doppler investigation is further improved by the recording of the pulmonary venous flow, which can be recorded in most of the patients following contrast injection. Therefore contrast enhanced transthoracic Doppler is an alternative to transesophageal Doppler investigation in patients with poor transthoracic windows.     

Grading of mitral regurgitation by quantitative Doppler echocardiography: calibration by left ventricular angiography in routine clinical practice

BACKGROUND: Quantitative Doppler echocardiography and proximal flow convergence methods are validated techniques for quantifying mitral regurgitation. However, the clinical interpretation of the values calculated is hindered by the absence of calibration of ranges of severity in large numbers of patients. METHODS AND RESULTS: In 180 consecutive patients (men, 62%; mean age+/-SD, 66+/-11 years), the results of Doppler quantification of isolated mitral regurgitation were calibrated by use of left ventricular angiographic grading performed within 3 months in routine practice and without intervening events. The thresholds of the quantitative variables corresponding to the angiographic grades were identified by maximizing the sum of sensitivity and specificity and minimizing their difference. The mitral regurgitation grade by angiography was 2.7+/-1.3. The mean value and correlation with angiographic grades for effective regurgitant orifice were 43+/-37 mm and r=.79 (P<.0001); for regurgitant volume, 62+/-45 mL and r=.80 (P<.0001); and for regurgitant fraction, 45+/-17% and r=.78 (P<.0001). Despite some overlap, differences between mitral regurgitation grades were all significant (all P<.05). The thresholds for severe mitral regurgitation (grade 4) were 60 mL, 50%, and 40 mm2 for regurgitant volume, regurgitant fraction, and orifice, respectively. CONCLUSIONS: In routine practice in large numbers of patients in a clinical laboratory, Doppler echocardiographic quantification of mitral regurgitation shows highly significant correlation with qualitative angiographic grades. Despite an expected overlap between classes, the calibration by angiography of grading ranges for the quantitative variables provides a framework for their interpretation and allows the definition in clinical practice of thresholds for severe mitral regurgitation.