(Circulation. 1997;96:3409-3415.)
© 1997 American Heart Association, Inc.
Articles |
From the Division of Cardiovascular Diseases and Internal Medicine (K.S.D., M.E.-S., R.A.N., J.B.S., A.J.T.) and the Section of Biostatistics (K.R.B.), Mayo Clinic and Mayo Foundation, Rochester, Minn.
| Abstract |
|---|
|
|
|---|
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.
Key Words: angiography echocardiography mitral valve regurgitation
| Introduction |
|---|
|
|
|---|
To define the degree of regurgitation quantitatively, new methods9 10 and new concepts11 12 using Doppler echocardiography have allowed the measurement of RVol, RF,13 14 15 and ERO, a measure of lesion severity.11 12 These methods have been validated and their accuracy verified in confirmatory studies.11 12 13 14 15 They can be used alternatively or in combination to define the degree of mitral regurgitation as values of RVol, RF, and ERO. However, because of their more recent application, a calibration and clinical perception of the values of these quantitative variablesparticularly the thresholds corresponding to severe mitral regurgitationhave not been fully developed. Preliminary values of these thresholds based on the physiological consequences of regurgitation have been suggested,12 but because of the limitations of pilot studies (ie, small numbers and possible selection bias), the calibration of a gradation framework in routine practice is warranted.
Because qualitative angiography has long been used in routine practice to assess mitral regurgitation,16 17 a clinical perception of the grades of mitral regurgitation, which is widely shared and comprehended, has formed despite the pitfalls of the method.18 Therefore, notwithstanding these pitfalls and the fact that angiographic grading is not a gold standard, it is a unique method to calibrate newer quantitative methods and to translate the perception of angiography to quantitative variables. Performed in routine practice, to avoid selection biases, this calibration should allow development of a framework for interpreting quantitative measurements of mitral regurgitation.
Therefore, our prospective experience with both Doppler echocardiographic quantification and angiographic assessment of mitral regurgitation obtained in routine practice was used to determine (1) thresholds of quantitative variables corresponding best to each angiographic grade and (2) a definition, based on these criteria, of severe mitral regurgitation as encountered in clinical practice.
| Methods |
|---|
|
|
|---|
30 mm Hg
between the two studies.
Echocardiographic Analysis
A comprehensive Doppler echocardiographic
examination was performed and analyzed as described
previously.19 20 21 The mechanism of mitral
regurgitation was determined on the basis of the
two-dimensional appearance of the left ventricle, subvalvular
apparatus, and valve leaflets and the dimension of the
mitral annulus. Organic mitral regurgitation was
characterized by intrinsic valvular disease, and
ischemic/functional mitral regurgitation was
characterized by normal valves, enlarged annulus, and global or
regional left ventricular dysfunction. Quantification of
mitral regurgitation was performed by two methods.
Quantitative Doppler method. As previously described,15 20 two-dimensional and Doppler echocardiography were used to make annular cross-sectional area and TVI measurements to calculate the mitral and aortic stroke volumes. Next, the Doppler RVol, RF, and ERO were calculated as follows: RVol=(mitral-aortic) stroke volume; RF=RVol/mitral stroke volume; and ERO=RVol/regurgitant TVI, where regurgitant TVI is the TVI (ie, stroke distance in centimeters) of the mitral regurgitant jet obtained by continuous-wave Doppler.
Proximal isovelocity area method. This method used
the proximal flow convergence22 23 24 and was performed as
previously described24 : regurgitant
flow=2
xr2xVr, where r is radius of
proximal flow convergence and Vr is aliasing velocity;
ERO=regurgitant flow/peak regurgitant velocity; RVol=EROxregurgitant
TVI; and RF=RVol/[(regurgitant+aortic) stroke volumes].
Final quantitative values. The final quantitative values of RVol, RF, and ERO were either the mean of those calculated by the two methods or the values calculated by the method used. Both methods were used in 40 patients, quantitative Doppler was used exclusively in 85, and proximal flow convergence was used exclusively in 55.
Angiographic Assessment
In each patient, left ventriculography was performed in a
biplane 30° right and 60° left anterior oblique projection with
50 mL of iopamidol (100% concentrated) injected over 3 to 4 seconds
and recorded on a 35-mm cinefilm at 60 frames per second. The
angiographic severity of mitral regurgitation was
graded according to a historically accepted grading
scheme16 17 in four grades (1, 2, 3, and 4, from mild to
severe). The left ventricular angiogram was interpreted at
the time of catheterization by an experienced
angiographer who reviewed the 35-mm film without knowledge that the
data would be analyzed for the present study.
Statistical Methods
Group results were reported as mean±SD for continuous
variables and as percentages for categorical variables. Group
comparison relied on the standard t test or, for multiple
group comparisons, on ANOVA. The relation between angiographic severity
of mitral regurgitation and RVol, RF, and ERO was
examined by use of the Spearman rank-order correlation.
For each quantitative variable (RVol, RF, and ERO), thresholds optimally separating the continuous quantitative variables in correspondence with the angiographic grades were determined sequentially for three levels, that is, for separation of grade 1 from 2, grades 1 and 2 from grades 3 and 4, and grade 3 from 4. The thresholds that best separated these angiographic grades were determined by testing the whole range of each variable by increments of 5 units (ie, 5 mL of RVol, 5% of RF, 5 mm2 of ERO) and determining for each level the sensitivity, specificity, negative and positive predictive values, odds ratio, and negative and positive likelihood ratios.25 The candidate thresholds that were considered to best separate the continuous quantitative variables in correspondence with the angiographic grades were those with the highest sum of sensitivity and specificity and the lowest value of their difference. If more than one value met these criteria, the final choice was made by prioritizing sensitivity. However, the results of alternative choices of interest were also presented. ROC curves were calculated for the diagnosis of grade 3 or 4 mitral regurgitation for the three quantitative variables, and the areas under the curves, which represent the diagnostic value of the quantitative variables, were compared by the paired t test. To determine the range of uncertainty of the thresholds between grades, the analysis was repeated with logistic regression between the angiographic grade (dependent, classified as grade 1 versus 2 to 4, 1 to 2 versus 3 to 4, and 1 to 3 versus 4) and quantitative degree of mitral regurgitation (independent), and the thresholds for each grade with their standard errors (by ANCOVA) were determined. All probability values were two-tailed, and a value of P<.05 was considered significant.
| Results |
|---|
|
|
|---|
|
Calibration of Echocardiographic Quantification
With Angiographic Grades
The mitral regurgitation grade by angiography was
2.7±1.3. The distribution of patients among the four angiographic
grades and the values of RVol, RF, and ERO for each angiographic grade
are summarized in Table 1
and demonstrate significant differences
between grades (overall P<.001, P<.001, and
P<.001 for RVol, RF, and ERO, respectively; all-group
comparison, P<.05). Significant correlation was found
between angiographic grades and ERO (r=.79,
P<.0001) (Fig 1
), RVol
(r=.80, P<.0001) (Fig 2
), and RF (r=.78,
P<.0001) (Fig 3
). There were
notable overlaps between grades (Figs 1 through 3![]()
![]()
), as expected, but
despite this, the differences between each angiographic grade in terms
of RVol, RF, and ERO were significant (Table 1
, all P<.05).
Possible threshold values for ERO, RVol, and RF corresponding to each
angiographic grade are listed in Table 2
,
with the descriptors of their diagnostic values. The
thresholds that were finally selected as best separating the grades at
each level are in boldface in Table 2
and summarized in Table 3
. The superimposition of the selected
thresholds on the scatterplots is shown in Figs 1B
, 2B
, and 3B
for ERO,
RVol, and RF, respectively. The area under the ROC curves for the
diagnosis of grade 3 to 4 mitral regurgitation was 0.93
for RVol, which was not significantly different from 0.92 for ERO
(P=.08) and 0.90 for RF (P=.08) (Fig 4
). The use of logistic regression to
determine the thresholds for the four grades yielded results similar to
those of the analysis based on the diagnostic value
and, most importantly, demonstrated that despite the overlap, the
standard errors of the thresholds were narrow (for RVol, 28±2.2,
47±2.7, and 62±3.4 mL; for RF, 31±3.4%, 42±1.4%, and 49±1.4%;
for ERO, 17±2, 31±2.2, and 43±2.7 mm2 for the
thresholds of grades 2, 3, and 4, respectively). No interaction was
found between the type of regurgitation (organic or
ischemic/functional) and the thresholds defined
(P=.08, .63, and .19, respectively, for RVol, RF, and
ERO).
|
|
|
|
|
|
| Discussion |
|---|
|
|
|---|
60 mL per beat, RF
50%, and
ERO
40 mm2.
Importance of Grading Mitral Regurgitation
The degree of mitral regurgitation is a
determinant of outcome in terms of both morbidity and mortality.
Patients with mild mitral regurgitation do not usually
develop left ventricular remodeling,12 26
whereas left ventricular dysfunction is a frequent and
serious complication of severe mitral
regurgitation.4 5 Moreover, in patients
with predominantly mild regurgitation, survival is
excellent,1 whereas in those with predominantly severe
regurgitation, excess mortality and high morbidity are
noted.2 Surgical correction of mitral
regurgitation is highly successful3 ;
however, the operative risk of valve repair or replacement, despite
recent improvements, is still not negligible.3 4 27
Therefore, surgery, particularly for patients with no or minimal
symptoms,28 should be considered mostly for patients with
well-documented severe mitral regurgitation.
Methods of Grading Mitral Regurgitation
Semiquantitative methods for the assessment of mitral
regurgitation often show disagreement,29
and all these techniques have important theoretical and practical
limitations. Semiquantification by the
echocardiographic color flow-jet area method has
pitfalls in that it tends to underestimate the severity of eccentric
jets6 7 and to overestimate the severity of central
jets.8 Quantitative methods allow the measurement of RVol
and RF to assess volume overload and also the measurement of ERO area,
a surrogate of lesion severity.11 12 Because quantitative
methods have only recently been introduced into routine
practice,9 10 13 15 a clinical comprehension and
perception of the values calculated have not yet developed. Calibration
of quantitative indexes was tentatively defined by determining
thresholds associated with marked degrees of left
ventricular enlargement and elevation of pulmonary
artery pressure,12 14 but full documentation of a
gradation framework is warranted.
Left ventricular angiography can define the degree of mitral regurgitation based on the retrograde opacification of the left atrium,16 17 but it is limited by its invasive nature and small inherent risk30 31 and thus cannot be used for regular follow-up. Another limitation is the frequent disagreement with the findings of other methods,29 and even in simultaneous studies, only modest correlations with quantitative indexes have been obtained.18 32 33 Therefore, the capacity of left ventricular angiography as a gold standard and accurate reference method in validation studies is questionable. However, one of its major merits is the historic use, which has created a clinical perception of the semiquantitative grading scale that is used to report angiographic degrees of mitral regurgitation.16 17 29 Therefore, left ventricular angiography is an essential tool for calibration of quantitative methods to define corresponding grading frameworks34 and to translate the perception of angiography to values reported by quantitative methods.
Pilot studies on new quantitative methods did not define ranges of degree of mitral regurgitation, for several reasons. First, the studies consisted of small populations of patients.12 13 15 35 36 Second, the pitfalls of the quantitative methods were not fully determined in the initial pilot studies, precluding meaningful comparison with angiography,9 10 37 but more recent studies have defined the field of applicability of the quantitative methods.12 14 22 38 Third, restrictive inclusion criteria of pilot studies23 24 35 36 necessary for validation of quantitative methods may induce a selection bias,39 40 leading to results that may not reflect the framework of gradation in routine practice. Therefore, calibration of quantitative measurements of mitral regurgitation using angiographic grades obtained in routine practice, as reported for the first time here, is essential. By design, without restrictive inclusion, a notable overlap between grades is expected.18 41 42 Despite this expected overlap, adequate correlations were found. Also, all angiographic grades showed significant differences in RVol, RF, and ERO, demonstrating that a statistical (in addition to visual) separation between grades is present. Furthermore, the diagnostic values of the thresholds defined in this study were good, allowing these thresholds to be used for the interpretation of quantitative data in routine clinical practice. Of note, regurgitation may not always be graded similarly by ERO and by RVol or RF. For any given ERO, higher afterload may result in higher RVol.43 Nevertheless, the present framework should allow enhanced comprehension of the results of quantitative methods and, in particular, of the role of lesion severity11 12 and loading conditions26 43 in the overall severity of mitral regurgitation.
What Is Severe Mitral Regurgitation?
The ROC curves in Fig 4
suggest that the quantitative methods are
an excellent test to distinguish grade 1 to 2 from grade 3 to 4. This
implies that several candidate threshold values can be identified that
have both good sensitivity and good specificity to separate between
grades, as reported in Table 2
. For example, for the threshold
separating grade 3 from grade 4, an ERO of 50 mm2
prioritized specificity but had a low sensitivity, and a threshold of
40 mm2 prioritized sensitivity with some loss in
specificity. The final choice is to be made by each physician depending
on the goals defined for routine clinical practice. The boldface values
in Table 2
represent our final choice, based mostly on
prioritizing sensitivity for severe degrees of mitral
regurgitation.
Table 3
summarizes these choices. The thresholds of RVol
60 mL/beat,
RF
50%, and ERO area
40 mm2 provide a relatively
high sensitivity for severe, grade 4 mitral
regurgitation. The corresponding thresholds for mitral
regurgitation of grade 3 or 4 are 45 mL/beat, 40%, and
30 mm2, respectively. These thresholds are close to
the ranges defined previously on the magnitude of the
pathophysiological consequences of mitral
regurgitation.12 They are also
consistent with the limited data previously available with
other quantitative methods.32 33 44 Ultimately, the exact
definition of severe mitral regurgitation should be
determined by the influence of the degree of volume overload (RVol and
RF) and lesion severity (ERO) on long-term outcome. However, follow-up
since the inception of the most applicable methods is limited and
cannot provide this crucial outcome information at the present
time.9 10 11 12 Therefore, the present calibration of
quantitative measures of the degree of mitral
regurgitation by angiography represents a
unique possibility of defining a framework of gradation and is
essential for the clinical use of quantitative data. Such a framework,
congruent with the long-used and well-perceived semiquantitative
gradation, should allow a better perception of the values calculated by
quantitative Doppler echocardiographic methods and
improve communication between physicians.29
Study Limitations
Not all patients in the present study had results of
quantification by two methods. However, the two Doppler
echocardiographic methods used to calculate ERO, RVol,
and RF show high correlations in the present study
(r=.94, P<.0001; r=.93,
P<.0001; r=.92, P<.0001,
respectively), as in previous studies,14 and no
significant difference in their results (P=.09,
P=.84, and P=.10, respectively). Also, the ROC
curves of RVol, RF, and ERO for the separation of grade 1 to 2 from
grade 3 to 4 did not differ between the two methods. Therefore, the
methods used do not represent a limitation but rather reflect
the use of quantification of regurgitation in routine
practice.
The patients included in the present study had chronic mitral regurgitation; therefore, the thresholds defined for severe mitral regurgitation apply primarily to chronic and not to acute mitral regurgitation. Future studies should analyze the pathophysiology of acute mitral regurgitation to better define specific diagnostic criteria.
A change in loading conditions between echocardiography and angiography could account for some of the misclassifications between quantification and angiographic grade observed in this study.43 Despite a significant difference between systolic blood pressure at the time of echocardiography and angiography, the absolute difference was small and the hemodynamic conditions were clinically similar. In routine practice, these tests are rarely performed simultaneously, and despite possible changes in loading conditions, the interpretation of the nonsimultaneous grading guides all clinical decisions. Therefore, the design of the present study is highly relevant to routine clinical practice.29
Furthermore, the aim of the present study was not to validate the quantitative methods, which have been endorsed in multiple studies from various medical centers,6 9 10 11 12 13 15 41 42 but rather to calibrate for the first time ranges of severity. Angiography may be conducive to misclassifications, which may partly explain the overlap observed,18 but these random misclassifications, which may reduce the coefficient of correlation, have little effect on the determination of the thresholds45 corresponding to the four grades and therefore do not hinder the present calibration. This is confirmed by the narrow standard error of the thresholds defined by the logistic regression, further emphasizing that the overlap does not represent a significant limitation of the present study.
Clinical Implications
Despite an overlap between angiographic grades, as expected in
routine practice, the diagnostic value of the quantitative
Doppler variables is excellent, as demonstrated by the ROC
curves. Therefore, in most cases, duplication of gradation does not
appear to be indispensable. The calibration of quantitative Doppler
echocardiographic measures of the degree of mitral
regurgitation by angiographic grading provides grading
ranges for the quantitative variables and should allow an improved
perception of the meaning and interpretation of the measured values. On
the basis of this calibration, patients with RVol
60 mL, RF
50%,
and ERO
40 mm2 are classified as having severe
mitral regurgitation.
| Selected Abbreviations and Acronyms |
|---|
|
| Acknowledgments |
|---|
| Footnotes |
|---|
Received January 30, 1997; revision received May 29, 1997; accepted July 3, 1997.
| References |
|---|
|
|
|---|
2.
Ling LH, Enriquez-Sarano M, Seward JB, Tajik AJ,
Schaff HV, Bailey KR, Frye RL. Clinical outcome of mitral
regurgitation due to flail leaflet.
N Engl J Med. 1996;335:1417-1423.
3.
Enriquez-Sarano M, Schaff HV, Orszulak TA, Tajik AJ,
Bailey KR, Frye RL. Valve repair improves the outcome of surgery
for mitral regurgitation: a
multivariate analysis.
Circulation. 1995;91:1022-1028.
4.
Enriquez-Sarano M, Tajik AJ, Schaff HV, Orszulak TA,
Bailey KR, Frye RL. Echocardiographic prediction
of survival after surgical correction of organic mitral
regurgitation. Circulation. 1994;90:830-837.
5. Enriquez-Sarano M, Tajik AJ, Schaff HV, Orszulak TA, McGoon MD, Bailey KR, Frye RL. Echocardiographic prediction of left ventricular function after correction of mitral regurgitation: results and clinical implications. J Am Coll Cardiol. 1994;24:1536-1543.[Abstract]
6. Enriquez-Sarano M, Tajik AJ, Bailey KR, Seward JB. Color flow imaging compared with quantitative Doppler assessment of severity of mitral regurgitation: influence of eccentricity of jet and mechanism of regurgitation. J Am Coll Cardiol. 1993;21:1211-1219.[Abstract]
7.
Chen CG, Thomas JD, Anconina J, Harrigan P,
Mueller L, Picard MH, Levine RA, Weyman AE. Impact of impinging
wall jet on color Doppler quantification of mitral
regurgitation. Circulation. 1991;84:712-720.
8. McCully RB, Enriquez-Sarano M, Tajik AJ, Seward JB. Overestimation of severity of ischemic/functional mitral regurgitation by color Doppler jet area. Am J Cardiol. 1994;74:790-793.[Medline] [Order article via Infotrieve]
9.
Bargiggia GS, Tronconi L, Sahn DJ, Recusani F, Raisaro
A, De Servi S, Valdes-Cruz LM, Montemartini C. A new method for
quantitation of mitral regurgitation based on color
flow Doppler imaging of flow convergence proximal to regurgitant
orifice. Circulation. 1991;84:1481-1489.
10.
Recusani F, Bargiggia GS, Yoganathan AP, Raisaro
A, Valdes-Cruz LM, Sung HW, Bertucci C, Gallati M, Moises VA, Simpson
IA, Tronconi L, Sahn DJ. A new method for quantification of
regurgitant flow rate using color Doppler flow imaging of the flow
convergence region proximal to a discrete orifice: an in vitro
study. Circulation. 1991;83:594-604.
11.
Vandervoort PM, Rivera JM, Mele D, Palacios IF,
Dinsmore RE, Weyman AE, Levine RA, Thomas JD. Application of
color Doppler flow mapping to calculate effective regurgitant
orifice area: an in vitro study and initial clinical
observations. Circulation. 1993;88:1150-1156.
12. Enriquez-Sarano M, Seward JB, Bailey KR, Tajik AJ. Effective regurgitant orifice area: a noninvasive Doppler development of an old hemodynamic concept. J Am Coll Cardiol. 1994;23:443-451.[Abstract]
13.
Blumlein S, Bouchard A, Schiller NB, Dae M, Byrd BF
III, Ports T, Botvinick EH. Quantitation of mitral
regurgitation by Doppler
echocardiography. Circulation. 1986;74:306-314.
14.
Enriquez-Sarano M, Bailey KR, Seward JB, Tajik AJ,
Krohn MJ, Mays JM. Quantitative Doppler assessment of
valvular regurgitation.
Circulation. 1993;87:841-848.
15. Rokey R, Sterling LL, Zoghbi WA, Sartori MP, Limacher MC, Kuo LC, Quinones MA. Determination of regurgitant fraction in isolated mitral or aortic regurgitation by pulsed Doppler two-dimensional echocardiography. J Am Coll Cardiol. 1986;7:1273-1278.[Abstract]
16. Grossman W, Dexter L. Profiles in valvular heart disease. In: Grossman W, ed. Cardiac Catheterization and Angiography. 2nd ed. Philadelphia, Pa: Lea & Febiger; 1980:305-324.
17. Sellers RD, Levy MJ, Amplatz K, Lillehei CW. Left retrograde cardioangiography in acquired cardiac disease: technic, indications and interpretations in 700 cases. Am J Cardiol. 1964;14:437-447.[Medline] [Order article via Infotrieve]
18. Croft CH, Lipscomb K, Mathis K, Firth BG, Nicod P, Tilton G, Winniford MD, Hillis LD. Limitations of qualitative angiographic grading in aortic or mitral regurgitation. Am J Cardiol. 1984;53:1593-1598.[Medline] [Order article via Infotrieve]
19. Nishimura RA, Miller FA Jr, Callahan MJ, Benassi RC, Seward JB, Tajik AJ. Doppler echocardiography: theory, instrumentation, technique, and application. Mayo Clin Proc. 1985;60:321-343.[Medline] [Order article via Infotrieve]
20.
Lewis JF, Kuo LC, Nelson JG, Limacher MC, Quinones
MA. Pulsed Doppler echocardiographic
determination of stroke volume and cardiac output: clinical validation
of two new methods using the apical window.
Circulation. 1984;70:425-431.
21. Tajik AJ, Seward JB, Hagler DJ, Mair DD, Lie JT. Two-dimensional real-time ultrasonic imaging of the heart and great vessels: technique, image orientation, structure identification, and validation. Mayo Clin Proc. 1978;53:271-303.[Medline] [Order article via Infotrieve]
22.
Pu M, Vandervoort PM, Griffin BP, Leung DY, Stewart WJ,
Cosgrove DM III, Thomas JD. Quantification of mitral
regurgitation by the proximal convergence method using
transesophageal echocardiography:
clinical validation of a geometric correction for proximal flow
constraint. Circulation. 1995;92:2169-2177.
23. Giesler M, Grossmann G, Schmidt A, Kochs M, Langhans J, Stauch M, Hombach V. Color Doppler echocardiographic determination of mitral regurgitant flow from the proximal velocity profile of the flow convergence region. Am J Cardiol. 1993;71:217-224.[Medline] [Order article via Infotrieve]
24. Enriquez-Sarano M, Miller FA Jr, Hayes SN, Bailey KR, Tajik AJ, Seward JB. Effective mitral regurgitant orifice area: clinical use and pitfalls of the proximal isovelocity surface area method. J Am Coll Cardiol. 1995;25:703-709.[Abstract]
25. Weissler AM. Assessment and use of cardiovascular tests in clinical prediction. In: Giuliani ER, Gersh BJ, McGoon MD, Hayes DL, Schaff HV, eds. Mayo Clinic Practice of Cardiology. 3rd ed. St Louis, Mo: Mosby; 1996:400-421.
26. Bolen JL, Alderman EL. Ventriculographic and hemodynamic features of mitral regurgitation of cardiomyopathic, rheumatic and nonrheumatic etiology. Am J Cardiol. 1977;39:177-183.[Medline] [Order article via Infotrieve]
27. Scott WC, Miller DC, Haverich A, Mitchell RS, Oyer PE, Stinson EB, Jamieson SW, Baldwin JC, Shumway NE. Operative risk of mitral valve replacement: discriminant analysis of 1329 procedures. Circulation. 1985;72(suppl II):II-108-II-119.
28.
Enriquez-Sarano M, Sinak LJ, Tajik AJ, Bailey KR,
Seward JB. Changes in effective regurgitant orifice throughout
systole in patients with mitral valve prolapse: a clinical study using
the proximal isovelocity surface area method.
Circulation. 1995;92:2951-2958.
29. Slater J, Gindea AJ, Freedberg RS, Chinitz LA, Tunick PA, Rosenzweig BP, Winer HE, Goldfarb A, Perez JL, Glassman E, Kronzon I. Comparison of cardiac catheterization and Doppler echocardiography in the decision to operate in aortic and mitral valve disease. J Am Coll Cardiol. 1991;17:1026-1036.[Abstract]
30. Lozner EC, Johnson LW, Johnson S, Krone R, Pichard AD, Vetrovec GW, Noto TJ. Coronary arteriography 1984-1987: a report of the Registry of the Society for Cardiac Angiography and Interventions, II: an analysis of 218 deaths related to coronary arteriography. Cathet Cardiovasc Diagn. 1989;17:11-14.[Medline] [Order article via Infotrieve]
31.
Davis K, Kennedy JW, Kemp HG Jr, Judkins MP, Gosselin
AJ, Killip T. Complications of coronary arteriography
from the Collaborative Study of Coronary Artery Surgery
(CASS). Circulation. 1979;59:1105-1112.
32. Lopez JF, Hanson S, Orchard RC, Tan L. Quantification of mitral valvular incompetence. Cathet Cardiovasc Diagn. 1985;11:139-152.[Medline] [Order article via Infotrieve]
33. Sandler H, Dodge HT, Hay RE, Rackley CE. Quantitation of valvular insufficiency in man by angiocardiography. Am Heart J. 1963;65:501-513.[Medline] [Order article via Infotrieve]
34. Pu M, Vandervoort PM, Griffin BP, Stewart WJ, Rodriguez L, Cosgrove DM, Thomas JD. Assessment of mitral regurgitant severity using quantitative Doppler transesophageal echocardiography: comparison with angiography. J Am Coll Cardiol. 1996;27(suppl A):349A. Abstract.
35. Mego DM, Nottestad SY, McClure JW, Rubal BR. Validation of a new Doppler-echocardiographic method for quantifying mitral regurgitation. J Am Soc Echocardiogr. 1995;8:897-903.[Medline] [Order article via Infotrieve]
36.
Schwammenthal E, Chen C, Benning F, Block M, Breithardt
G, Levine RA. Dynamics of mitral regurgitant flow and orifice
area: physiologic application of the proximal flow convergence method:
clinical data and experimental testing. Circulation. 1994;90:307-322.
37. Chen C, Koschyk D, Brockhoff C, Heik S, Hamm C, Bleifeld W, Kupper W. Noninvasive estimation of regurgitant flow rate and volume in patients with mitral regurgitation by Doppler color mapping of accelerating flow field. J Am Coll Cardiol. 1993;21:374-383.[Abstract]
38.
Rodriguez L, Anconina J, Flachskampf FA, Weyman AE,
Levine RA, Thomas JD. Impact of finite orifice size on
proximal flow convergence: implications for Doppler quantification
of valvular regurgitation. Circ
Res. 1992;70:923-930.
39. Salerno DM, Wang K, Goldenberg IF, Van Tassel RA. The impact of selection bias on measurement of noninvasive test accuracy. Am J Cardiol. 1993;72:223-225. Editorial.[Medline] [Order article via Infotrieve]
40.
Miller MG, Miller LS, Fireman B, Black SB.
Variation in practice for discretionary admissions: impact on estimates
of quality of hospital care. JAMA. 1994;271:1493-1498.
41. Zhang Y, Ihlen H, Myhre E, Levorstad K, Nitter-Hauge S. Quantification of mitral regurgitation by Doppler echocardiography. Eur Heart J. 1987;8(suppl C):59-62.
42.
Tribouilloy C, Shen WF, Slama MA, Dufosse H, Choquet D,
Marek A, Lesbre JP. Non-invasive measurement of the regurgitant
fraction by pulse Doppler echocardiography in
isolated pure mitral regurgitation. Br
Heart J. 1991;66:290-294.
43.
Borgenhagen DM, Serur JR, Gorlin R, Adams D,
Sonnenblick EH. The effects of left ventricular load
and contractility on mitral regurgitant orifice size
and flow in the dog. Circulation. 1977;56:106-113.
44. Geffers H, Stauch M. Assessment of regurgitation fractions by radionuclide ventriculography. Z Kardiol. 1979;68:491-496.[Medline] [Order article via Infotrieve]
45. Viana MA. Bayesian small-sample estimation of misclassified multinomial data. Biometrics. 1994;50:237-243.[Medline] [Order article via Infotrieve]
This article has been cited by other articles:
![]() |
R. Pizarro, O. O. Bazzino, P. F. Oberti, M. Falconi, F. Achilli, A. Arias, J. G. Krauss, and A. M. Cagide Prospective validation of the prognostic usefulness of brain natriuretic peptide in asymptomatic patients with chronic severe mitral regurgitation. J. Am. Coll. Cardiol., September 15, 2009; 54(12): 1099 - 1106. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. V. Schaff Asymptomatic Severe Mitral Valve Regurgitation: Observation or Operation? Circulation, February 17, 2009; 119(6): 768 - 769. [Full Text] [PDF] |
||||
![]() |
S. Buchner, K. Debl, F. Poschenrieder, S. Feuerbach, G. A.J. Riegger, A. Luchner, and B. Djavidani Cardiovascular Magnetic Resonance for Direct Assessment of Anatomic Regurgitant Orifice in Mitral Regurgitation Circ Cardiovasc Imaging, September 1, 2008; 1(2): 148 - 155. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Buck, B. Plicht, P. Kahlert, I. M. Schenk, P. Hunold, and R. Erbel Effect of Dynamic Flow Rate and Orifice Area on Mitral Regurgitant Stroke Volume Quantification Using the Proximal Isovelocity Surface Area Method J. Am. Coll. Cardiol., August 26, 2008; 52(9): 767 - 778. [Abstract] [Full Text] [PDF] |
||||
![]() |
P A Grayburn How to measure severity of mitral regurgitation Postgrad. Med. J., August 1, 2008; 84(994): 395 - 402. [Full Text] [PDF] |
||||
![]() |
P. A Grayburn How to measure severity of mitral regurgitation Heart, March 1, 2008; 94(3): 376 - 383. [Full Text] [PDF] |
||||
![]() |
B. W.L. De Boeck, M. Meine, G. E. Leenders, A. J. Teske, H. van Wessel, J. H. Kirkels, F. W. Prinzen, P. A. Doevendans, and M. J. Cramer Practical and conceptual limitations of tissue Doppler imaging to predict reverse remodelling in cardiac resynchronisation therapy Eur J Heart Fail, March 1, 2008; 10(3): 281 - 290. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. I. Fann, N. B. Ingels Jr., and D. C. Miller Pathophysiology of Mitral Valve Disease Card. Surg. Adult, January 1, 2008; 3(2008): 973 - 1012. [Full Text] |
||||
![]() |
A. Marciniak, P. Claus, G. R. Sutherland, M. Marciniak, T. Karu, A. Baltabaeva, E. Merli, B. Bijnens, and M. Jahangiri Changes in systolic left ventricular function in isolated mitral regurgitation. A strain rate imaging study Eur. Heart J., November 1, 2007; 28(21): 2627 - 2636. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Messika-Zeitoun, M. Bellamy, J.-F. Avierinos, J. Breen, C. Eusemann, A. Rossi, T. Behrenbeck, C. Scott, J. A. Tajik, and M. Enriquez-Sarano Left atrial remodelling in mitral regurgitation--methodologic approach, physiological determinants, and outcome implications: a prospective quantitative Doppler-echocardiographic and electron beam-computed tomographic study Eur. Heart J., July 2, 2007; 28(14): 1773 - 1781. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Alkadhi, S. Wildermuth, D. A. Bettex, A. Plass, B. Baumert, S. Leschka, L. M. Desbiolles, B. Marincek, and T. Boehm Mitral Regurgitation: Quantification with 16-Detector Row CT--Initial Experience Radiology, December 21, 2005; (2005) 2381042216. [Abstract] [Full Text] |
||||
![]() |
J.-L. Monin, P. Dehant, C. Roiron, M. Monchi, J.-Y. Tabet, P. Clerc, G. Fernandez, R. Houel, J. Garot, C. Chauvel, et al. Functional Assessment of Mitral Regurgitation by Transthoracic Echocardiography Using Standardized Imaging Planes: Diagnostic Accuracy and Outcome Implications J. Am. Coll. Cardiol., July 19, 2005; 46(2): 302 - 309. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Uemura, Y. Otsuji, K. Nakashiki, S. Yoshifuku, Y. Maki, B. Yu, N. Mizukami, E. Kuwahara, S. Hamasaki, S. Biro, et al. Papillary Muscle Dysfunction Attenuates Ischemic Mitral Regurgitation in Patients With Localized Basal Inferior Left Ventricular Remodeling: Insights From Tissue Doppler Strain Imaging J. Am. Coll. Cardiol., July 5, 2005; 46(1): 113 - 119. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. O. Bonow, M. D. Cheitlin, M. H. Crawford, and P. S. Douglas Task Force 3: Valvular heart disease J. Am. Coll. Cardiol., April 19, 2005; 45(8): 1334 - 1340. [Full Text] [PDF] |
||||
![]() |
M. Enriquez-Sarano, J.-F. Avierinos, D. Messika-Zeitoun, D. Detaint, M. Capps, V. Nkomo, C. Scott, H. V. Schaff, and A. J. Tajik Quantitative Determinants of the Outcome of Asymptomatic Mitral Regurgitation N. Engl. J. Med., March 3, 2005; 352(9): 875 - 883. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Grigioni, D. Detaint, J.-F. Avierinos, C. Scott, J. Tajik, and M. Enriquez-Sarano Contribution of ischemic mitral regurgitation to congestive heart failure after myocardial infarction J. Am. Coll. Cardiol., January 18, 2005; 45(2): 260 - 267. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Kanzaki, R. Bazaz, D. Schwartzman, K. Dohi, L. E. Sade, and J. Gorcsan III A mechanism for immediate reduction in mitral regurgitation after cardiac resynchronization therapy: Insights from mechanical activation strain mapping J. Am. Coll. Cardiol., October 19, 2004; 44(8): 1619 - 1625. [Abstract] [Full Text] [PDF] |
||||
![]() |
A Vitarelli, Y Conde, E Cimino, T Leone, I D'Angeli, S D'Orazio, and S Stellato Assessment of severity of mechanical prosthetic mitral regurgitation by transoesophageal echocardiography Heart, May 1, 2004; 90(5): 539 - 544. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. A. Zoghbi, M. Enriquez-Sarano, E. Foster, P. A. Grayburn, C. D. Kraft, R. A. Levine, P. Nihoyannopoulos, C. M. Otto, M. A. Quinones, H. Rakowski, et al. American Society of Echocardiography: recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and Doppler echocardiography : A report from the American Society of Echocardiography's Nomenclature and Standards Committee and The Task Force on Valvular Regurgitation, developed in conjunction with the American College of Cardiology Echocardiography Committee, The Cardiac Imaging Committee, Council on Clinical Cardiology, The American Heart Association, and the European Society of Cardiology Working Group on Echocardiography, represented by: Eur J Echocardiogr, December 1, 2003; 4(4): 237 - 261. [Full Text] [PDF] |
||||
![]() |
P. Lancellotti, P. Troisfontaines, A.-C. Toussaint, and L. A. Pierard Prognostic Importance of Exercise-Induced Changes in Mitral Regurgitation in Patients With Chronic Ischemic Left Ventricular Dysfunction Circulation, October 7, 2003; 108(14): 1713 - 1717. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. I. Fann, N. B. Ingels Jr., and D. C. Miller Pathophysiology of Mitral Valve Disease Card. Surg. Adult, January 1, 2003; 2(2003): 901 - 931. [Full Text] |
||||
![]() |
S. H. Rahimtoola Drug-Related Valvular Heart Disease: Here We Go Again: Will We Do Better This Time? Mayo Clin. Proc., December 1, 2002; 77(12): 1275 - 1277. [PDF] |
||||
![]() |
M Enriquez-Sarano and C Tribouilloy Quantitation of mitral regurgitation: rationale, approach, and interpretation in clinical practice Heart, November 1, 2002; 88(90004): iv1 - 3. [Full Text] [PDF] |
||||
![]() |
T Irvine, X K Li, D J Sahn, and A Kenny Assessment of mitral regurgitation Heart, November 1, 2002; 88(90004): iv11 - 19. [Full Text] [PDF] |
||||
![]() |
B. Iung, C. Gohlke-Barwolf, P. Tornos, C. Tribouilloy, R. Hall, E. Butchart, and A. Vahanian Recommendations on the management of the asymptomatic patient with valvular heart disease Eur. Heart J., August 2, 2002; 23(16): 1253 - 1266. [PDF] |
||||
![]() |
Y. Otsuji, T. Kumanohoso, S. Yoshifuku, K. Matsukida, C. Koriyama, A. Kisanuki, S. Minagoe, R. A. Levine, and C. Tei Isolated annular dilation does not usually cause important functional mitral regurgitation: Comparison between patients with lone atrial fibrillation and those with idiopathic or ischemic cardiomyopathy J. Am. Coll. Cardiol., May 15, 2002; 39(10): 1651 - 1656. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. H. Gaasch and G. P. Aurigemma Inhibition of therenin-angiotensin systemand the left ventricularadaptation to mitral regurgitation J. Am. Coll. Cardiol., April 17, 2002; 39(8): 1380 - 1383. [Full Text] [PDF] |
||||
![]() |
F. Grigioni, M. Enriquez-Sarano, K. J. Zehr, K. R. Bailey, and A. J. Tajik Ischemic Mitral Regurgitation : Long-Term Outcome and Prognostic Implications With Quantitative Doppler Assessment Circulation, April 3, 2001; 103(13): 1759 - 1764. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E. Moller, E. Sondergaard, S. H. Poulsen, and K. Egstrup Pseudonormal and restrictive filling patterns predict left ventricular dilation and cardiac death after a first myocardial infarction: a serial color M-mode doppler echocardiographic study J. Am. Coll. Cardiol., November 15, 2000; 36(6): 1841 - 1846. [Abstract] [Full Text] [PDF] |
||||
![]() |
T Irvine, X N Li, R Rusk, D Lennon, D J Sahn, and A Kenny Three dimensional colour Doppler echocardiography for the characterisation and quantification of cardiac flow events Heart, November 1, 2000; 84(90002): 2i - 6. [Full Text] |
||||
![]() |
C. M. Tribouilloy, M. Enriquez-Sarano, K. R. Bailey, J. B. Seward, and A. J. Tajik Assessment of Severity of Aortic Regurgitation Using the Width of the Vena Contracta : A Clinical Color Doppler Imaging Study Circulation, August 1, 2000; 102(5): 558 - 564. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E. Moller, E. Sondergaard, J. B. Seward, C. P. Appleton, and K. Egstrup Ratio of left ventricular peak E-wave velocity to flow propagation velocity assessed by color M-mode Doppler echocardiography in first myocardial infarction: Prognostic and clinical implications J. Am. Coll. Cardiol., February 1, 2000; 35(2): 363 - 370. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Enriquez-Sarano, A.-J. Basmadjian, A. Rossi, K. R. Bailey, J. B. Seward, and A. J. Tajik Progression of mitral regurgitation: A prospective Doppler echocardiographic study J. Am. Coll. Cardiol., October 1, 1999; 34(4): 1137 - 1144. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. Sun, X. S. Yang, J. X. Qin, N. L. Greenberg, J. Zhou, C. J. Vazquez, B. P. Griffin, W. J. Stewart, and J. D. Thomas Quantification of mitral regurgitation by automated cardiac output measurement: experimental and clinical validation J. Am. Coll. Cardiol., October 1, 1998; 32(4): 1074 - 1082. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Kizilbash, D. L. Willett, M. E. Brickner, S. K. Heinle, and P. A. Grayburn Effects of afterload reduction on vena contracta width in mitral regurgitation J. Am. Coll. Cardiol., August 1, 1998; 32(2): 427 - 431. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1997 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |