Quantification of mitral regurgitation orifice area by 3-dimensional echocardiography: comparison with effective regurgitant orifice area by PISA method and proximal regurgitant jet diameter

BACKGROUND: The evaluation of mitral regurgitation (MR) by 3-dimensional (3D) echo has generally been performed by reconstruction of Doppler regurgitant jets but there are little data on measuring anatomic regurgitant orifice area (AROA) directly from 3D mitral valve (MV) reconstructions. METHODS AND RESULTS: Transoesophageal echo (TOE) 3D images were acquired from 38 unselected patients (age 59+/-11 years, ten in atrial fibrillation) with various degrees of MR. In all patients MV was reconstructed en face from the left atrium (LA) and the left ventricle (LV). AROA was measured by planimetry from 3D pictures and compared to the effective regurgitant orifice area (EROA) by proximal isovelocity surface area and proximal MR jet width from 2D echo. AROA was measured in 95% of patients from LA, 89% from LV and in 84% from both LA and LV. Good correlation was found between EROA and AROA measured from both LA (r=0.97, P<0.0001) and LV (r=0.87, P<0.0001). The mean difference between LA-AROA and EROA was -3.01+/-6.12 mm(2) and -7.18+/-13.84 mm(2) for LV-AROA (P<0.01, respectively). An acceptable correlation was found between the proximal MR jet width and AROA from LA (r=0.71, P<0.0001) and LV perspective (r=0.68, P<0.0001). AROA>or=25 mm(2) differentiated mild MR (graded 1-2) from moderately severe (graded 3-4) with 80-90% accuracy. CONCLUSIONS: 3D TOE provides important quantitative information on both the mechanism and the severity of MR in an unselected group of patients. AROA enables quantification of MR with excellent agreement with the accepted clinical method of proximal flow convergence.     

Can signal intensity of the continuous wave Doppler regurgitant jet estimate severity of mitral regurgitation?

Visual estimates of the intensity of the continuous wave (CW) Doppler regurgitant jet signal have been used to estimate the severity of valvular regurgitation. Theoretically, the strength of the reflected Doppler signal is a function of the number of scatterers. To test this approach quantitatively, free jets were produced in 27 experiments using a power injector and cornstarch suspension varying in concentration from 1% to 3%. Flow volume was varied from 5 to 15 ml, and orifice diameter varied from 2.5 to 10 mm. Machine settings were kept constant. Also, 22 patients with mitral regurgitation (MR)--5 mild, 11 moderate, and 6 severe by angiography--were studied. Average signal intensity under the CW Doppler flow curve was calculated using a computer image processor. In MR patients, average regurgitant flow (RF) intensity was compared with average mitral forward flow (FF) signal intensity. (1) The intensity under the CW flow signal in the free jet experiments correlated well with injection volume (r greater than 0.98). (2) RF average signal intensity did not correlate with angiographic MR severity (r = 0.21), but the ratio of RF to FF average signal intensity did correlate with MR severity (r = 0.73). (3) The sensitivity and the specificity of an RF/FF ratio greater than 0.65 for angiographically severe mitral regurgitation were both 83%. (4) The sensitivity and specificity of an RF/FF ratio less than 0.50 for angiographic mild mitral regurgitation were both 80%. The ratio of regurgitant to forward mitral flow CW Doppler signal intensity appears to be an accurate and clinically applicable method for estimating the severity of mitral regurgitation.     

Sources of variability for Doppler color flow mapping of regurgitant jets in an animal model of mitral regurgitation

To determine whether Doppler color flow mapping could be used to quantify changing levels of regurgitant flow and define the technical variables that influence the size of color flow images of regurgitant jets, nine stable hemodynamic states of mitral insufficiency were studied in four open chest sheep with regurgitant orifices of known size. The magnitude of mitral regurgitation was altered by phenylephrine infusion. Several technical variables, including the type of color flow instrument (Irex Aloka 880 versus Toshiba SSH65A), transducer frequency, pulse repetition frequency and gain level, were studied. Significant increases in the color flow area, but not in color jet width measurements, were seen after phenylephrine infusion for each regurgitant orifice. For matched levels of mitral regurgitation, an increase in gain resulted in a 125% increase in color flow area. An increase in the pulse repetition and transducer frequencies resulted in a 36% reduction and a 28% increase in color flow area, respectively. Jet area for matched regurgitant volumes was larger on the Toshiba compared with the Aloka instrument (5.2 +/- 3.1 versus 3.2 +/- 1.2 cm2, p less than 0.05). Color flow imaging of mitral regurgitant jets is dependent on various technical factors and the magnitude of regurgitation. Once these are standardized for a given patient, the measurement of color flow jet area may provide a means of making serial estimates of the severity of mitral insufficiency.     

The QuantumCor device for treating mitral regurgitation: An animal study

Objectives : The mitral annular contraction achieved could help reduce mitral regurgitation (MR), and with appropriate modifications, be applied to human subjects providing a potentially effective percutaneous method of valve repair. Background : MR is an important source of morbidity and is an independent predictor of mortality. A variety of percutaneous approaches are being developed to address this issue. We introduce a novel potential method utilizing radiofrequency (RF) energy to heat and shrink the mitral valve annulus in an animal model. Methods : In open‐heart procedures in 16 healthy sheep (six with naturally occurring MR), we used a malleable probe (QuantumCor, Lake Forest, CA) that conforms to the annular shape to deliver RF energy via a standard generator to replicate a surgical mitral annular ring. Seven sheep were followed chronically and their mitral annulus dimensions measured serially. Results : All sheep underwent intracardiac echocardiography or direct circumferential measurement of the mitral annulus before and after RF therapy. RF therapy was administered in less than 4 min in each case, and the mean anteroposterior (AP) annular distance was reduced by a mean of 23.8% (AP diameter reduction 5.75 ± 0.86 mm, P < 0.001) acutely. In the six sheep with nonischemic MR, regurgitation was eliminated. Acute histopathology (HP) demonstrated no damage to the leaflets, coronary sinuses, or coronary arteries. At the end of the intended 6‐month period of the chronic part of the study, four of the seven animals survived. The four treatment animals showed significant reductions in mitral A‐P dimension, with a percent diameter reduction of 26.4% (AP diameter reduction 7 ± 2.3 mm). Conclusion : The application of RF directly to heat the mitral annulus has resulted in sustained contraction of the annulus in this limited preclinical animal study. With further study and possible modifications, it holds promise for future application in human subjects with MR. © 2009 Wiley‐Liss, Inc.     

The spectrum of mitral regurgitation in idiopathic mitral valve prolapse: a Color Doppler study

To characterize the spectrum of mitral regurgitation in mitral valve prolapse, one hundred patients were studied by color Doppler flow mapping. The findings were correlated with the clinical presentation and with the possible complications. Mitral regurgitation was absent in 46 patients, mild in 26 patients, moderate in 18 patients and severe in 10 patients. The jet orientation was central in 15 patients, antero-medial in 13 patients and postero-lateral in 26 patients. The regurgitation was early systolic in 7 patients, late systolic in 20 patients and holosystolic in 27 patients. A good agreement was observed between the color flow patterns and the presence, timing and radiation of a murmur. Systolic clicks were not predictors of the presence or the severity of regurgitation. The grade of mitral regurgitation was positively correlated with age, left heart enlargement and valvular redundancy. No sex difference was observed. The prevalence of serious arrhythmias or cerebral ischemic events was not significantly increased when a regurgitation was present.     

Quantification of mitral regurgitation by Doppler color flow mapping: comparison of mitral regurgitant fraction and volume with Doppler measurements]

Color flow imaging of the regurgitant areas has been used to quantitate the severity of valvular regurgitation, however, the exact relationship between color flow areas and regurgitant volumes or fraction has not been clarified. This study was designed to determine whether measurements of jet flow areas and distances using color flow imaging are closely related to the regurgitant volume (MRV:ml/beat) and fraction (MRF: %). Doppler examinations were performed in 29 patients with mitral regurgitation (MR). The MR jet was depicted as the largest clearly definable flow disturbance on the echo images, and the maximal jet area (cm2) and length (cm) were measured. The MRV and MRF were obtained from the Doppler measurements of the transmitral flow (TMF) and the aortic flow (AF) as follows: MRV = TMF-AF, MRF = MRV/TMF x 100. The maximal jet area showed significant correlations with the MRV and MRF (r = 0.75 and 0.75, p < 0.01), and the maximal jet length showed even better correlations with the MRV and MRF (r = 0.82 and 0.80, p < 0.01), irrespective of the etiology of MR. Thus, both the maximal jet area and length obtained from color flow imaging can be simple and useful measurement methods for predicting the MRV and MRF.     

Assessment of severity of mitral regurgitation by measuring regurgitant jet width at its origin with transesophageal Doppler color flow imaging.

BACKGROUND. The ability of transesophageal color Doppler echocardiography to provide high-resolution images of both cardiac structure and blood flow in real time is advantageous for many clinical purposes. This study was performed to determine the utility of the regurgitant jet width at its origin measured by transesophageal Doppler color flow imaging in the assessment of severity of mitral regurgitation. METHODS AND RESULTS. Sixty-three consecutive patients with mitral regurgitation underwent transesophageal color Doppler examination, and the diameter of regurgitant jet at its origin was measured. Both right and left cardiac catheterizations were performed within 24 hours of Doppler studies, and angiographic grading of mitral regurgitation and regurgitant stroke volume were evaluated. There was a close relation between the jet diameter at its origin measured by transesophageal Doppler color flow imaging and the angiographic grade of mitral regurgitation (r = 0.86, p less than 0.001). A jet diameter of 5.5 mm or more identified severe mitral regurgitation (grade III or IV) with a sensitivity of 92%, specificity of 92%, and positive and negative predictive values of 88% and 95%, respectively. In 31 patients with isolated mitral regurgitation, the jet diameter correlated well with the regurgitant stroke volume determined by a combined hemodynamic-angiographic method (r = 0.85, p less than 0.001). A jet diameter of 5.5 mm or more identified a regurgitant stroke volume of 60 ml or more with a sensitivity of 88%, specificity of 93%, and positive and negative predictive values of 94% and 87%, respectively. CONCLUSIONS. The regurgitant jet width at its origin measured by transesophageal Doppler color flow imaging provides a simple and useful method of measuring the severity of mitral regurgitation, and it may allow differentiation between mild and severe mitral regurgitation.     

Color Doppler diagnosis of mechanical prosthetic mitral regurgitation: usefulness of the flow convergence region proximal to the regurgitant orifice

In prosthetic or paravalvular prosthetic mitral regurgitation, transthoracic color Doppler flow mapping can sometimes fail to detect the regurgitant jet within the left atrium because of the shadowing by the prosthetic valve. To overcome this limitation, we assessed the utility of color Doppler visualization of the flow convergence region (FCR) proximal to the regurgitant orifice in 20 consecutive patients with mechanical prosthetic mitral regurgitation documented by surgery and cardiac catheterization (13 of 20 patients). In addition, we studied 33 patients with normally functioning mitral prostheses. Doppler studies were performed in the apical, subcostal, and parasternal long-axis views. An FCR was detected in 95% (19 of 20) of patients with prosthetic mitral regurgitation. A jet area in the left atrium was detected in 60% (12 of 20) of patients. In 18 of 19 patients with Doppler-detected FCR, the site of the leak was correctly identified by observing the location of the FCR. A trivial jet area was detected in eight patients with a normally functioning mitral prosthesis; in none was an FCR identified. Thus color Doppler visualization of the FCR proximal to the regurgitant orifice is superior to the jet area in the diagnosis of mechanical prosthetic mitral regurgitation. Moreover, FCR permits localization of the site of the leak with good accuracy.     

Determinants of anterior mitral leaflet fluttering in pure aortic regurgitation from pulsed Doppler study of the early diastolic interaction between the regurgitant jet and mitral inflow

Fluttering of the anterior mitral leaflet may be absent in patients with moderate to severe aortic regurgitation (AR), suggesting that the volumetric severity of AR alone does not determine the presence or absence of abnormal diastolic mitral valve motion. Fifteen patients with moderate to severe AR and normal mitral valves, 9 of whom demonstrated anterior mitral leaflet fluttering, were studied to elucidate the determinants of abnormal anterior mitral leaflet motion in these patients. Pulsed Doppler mapping of the flow-velocity disturbance of AR demonstrated its presence in the third of the left ventricular outflow tract adjacent to the anterior mitral leaflet in 8 of 9 patients with anterior mitral leaflet fluttering and none of the 6 patients without anterior mitral leaflet fluttering (p less than 0.02). The impact of this regurgitant jet on early diastolic transmitral inflow was examined with pulsed Doppler in these 2 groups of patients with AR and in age-matched control subjects. Deceleration of early diastolic transmitral filling was slower in patients with AR and anterior mitral leaflet fluttering than in age-matched control subjects (283 +/- 107 vs 457 +/- 176 cm/s2, p less than 0.02), whereas it was not significantly different from controls in AR patients without anterior mitral leaflet fluttering. This resulted in significant prolongation of the duration of early diastolic transmitral filling in patients with AR and anterior mitral leaflet fluttering (297 +/- 93 vs 203 +/- 44 ms for age-matched control subjects, p less than 0.02), which was not observed in patients with AR who did not have anterior mitral leaflet fluttering.(ABSTRACT TRUNCATED AT 250 WORDS)     

Color M-mode regurgitant flow propagation velocity: a new echocardiographic method for grading of mitral regurgitation

PURPOSE: The aim of this study was to evaluate the reliability of mitral regurgitation color M-mode regurgitant flow propagation velocity (RFPV) in grading mitral regurgitation (MR). METHODS: We prospectively examined 52 consecutive patients with grades of MR mild in 10 patients, moderate in 19 patients, and severe in 23 patients with quantitative pulse Doppler echocardiography. MR was evaluated by vena contracta diameter (VCD), regurgitant jet area (RJA), and RFPV. These qualitative and quantitative methods were compared with the pulsed Doppler quantitative flow measurements and concordance of these three methods was determined. RESULTS: The mean RFPV for mild, moderate, and severe MR were 26.4 +/- 7 cm/sec, 43.3 +/- 7 cm/sec, and 60.3 +/- 7.3 respectively (P < 0.001). RFPV is highly sensitive and moderately specific in differentiating mild and severe MR from other subgroups. Sensitivity and specificity were 92.1%-64.3% for mild and 100%-68.5% for severe MR, respectively. Significant correlation was observed between pulse Doppler quantitative grades, RFPV, VC, and RJA (P < 0.0001, r = 0.87; P < 0.0001, r = -0.84; P < 0.0001, r = 0.76, respectively). CONCLUSION: This results show that RFPV is a reliable and simple semiquantitative new method that can be used for determining severity of MR.     

Color Doppler echocardiographic assessment of the change in the mitral regurgitant volume

We studied the possibility that a mitral regurgitant Doppler signal area on a two-dimensional color Doppler echocardiogram can reflect changes in mitral regurgitant volume in 24 patients with several types of mitral regurgitation. In 20 patients, mitral regurgitant Doppler signal areas were clear enough to measure. Injections of phenylephrine were given to these patients during the recording of the mitral regurgitant Doppler signal area in the same views and with the same Doppler gains. The mitral regurgitant Doppler signal area, blood pressure, and heart rate were measured before and after phenylephrine provocation. In addition, inhalation of amyl nitrite was performed during the recording of the mitral regurgitant Doppler signal area in the same way. Injection of phenylephrine resulted in an increase in the mitral regurgitant Doppler signal area accompanied by an increase in blood pressure and a decrease in heart rate. On the other hand, inhalation of amyl nitrite resulted in a decrease in the mitral regurgitant Doppler signal area, a decrease in blood pressure, and an increase in heart rate. A positive correlation between the change in blood pressure and that in the mitral regurgitant Doppler signal area was observed. In conclusion, two-dimensional color Doppler echocardiography may be useful in the assessment of the acute change in regurgitant volume in the patient with mitral regurgitation.     

A regurgitant jet and echocardiographic abnormalities in aortic regurgitation: an experimental study

Acute aortic regurgitation was created experimentally in 21 mongrel dogs to examine the relationship of the regurgitant jet to observed echocardiographic findings. The direction of the regurgitant jet was studied by echo contrast injections in the aortic root. Diastolic fluttering of the anterior mitral leaflet (AML) was noted in all 21 dogs irrespective of direction of the jet. Diastolic fluttering of the interventricular septum (IVS) was noted in six of the seven dogs with a tear of the noncoronary cusp and in one of seven dogs with lesions in the left coronary cusp. In all seven dogs with echocardiographically demonstrated IVS fluttering, a regurgitant jet impinged on the anterior part of the IVS. Amplitude of the AML excursion was not significantly different from control when the lesions involved the noncoronary or the left coronary cusps. However, all seven dogs that had a lesion in the right coronary cusp demonstrated a significant reduction in the amplitude of the AML excursion. The regurgitant jet in these dogs impinged uniformly on the AML. We conclude that diastolic fluttering of the AML is uniformly observed and unrelated to the direction of the regurgitant jet, diastolic fluttering of the IVS is caused by the regurgitant jet impinging upon the IVS, and amplitude of the AML may be reduced as a result of a jet impingement of the AML.     

Color Doppler regurgitant characteristics of normal mechanical mitral valve prostheses in vitro.

BACKGROUND. To evaluate normal regurgitant characteristics of St. Jude (SJ) and Medtronic-Hall (MH) mitral valves, four sizes (25-31 mm) of each were studied in a pulsatile flow model. METHODS AND RESULTS. Regurgitant flow was measured by flowmeter at left ventricular pressures of 80, 130, and 180 mm Hg. Peak regurgitant flow rates ranged from 6.2 to 12.7 cm3/sec in SJ valves and from 7.9 to 17.5 cm3/sec in MH valves. Regurgitant orifice areas calculated from the Doppler continuity equation ranged from 1.6 to 2.0 mm2 in SJ valves and from 2.2 to 2.9 mm2 in MH valves. Regurgitant volumes across the closed valve at a left ventricular pressure of 130 mm Hg were normalized to an ejection time of 280 msec and ranged from 1.5 to 1.9 cm3 in SJ valves and from 2.1 to 2.8 cm3 in MH valves. Jets were imaged by color Doppler in six rotational planes, and jet size and morphology were compared with those of regurgitant jets from circular orifices with sizes comparable to the calculated prosthetic valve regurgitant orifices (1.1-3.1 mm2). SJ valves showed two converging jets from the pivot points, one central jet, and a variable number of peripheral jets. The mean color jet area derived from the six image planes ranged from 1.6 to 5.3 cm2. Aliasing occurred only close to the valve (maximal distance 0.5-2.0 cm). MH valves showed a large central jet with a maximal length of aliased flow between 2.0 and 5.5 cm. Depending on valve size, driving pressure, and image plane, one or two small peripheral jets were found. These jets did not show aliasing in any case. The mean color jet area ranged from 5.1 to 11.0 cm2. Jets originating from circular orifices of comparable size showed jet areas from 5.5 to 13.9 cm2 and aliasing distances from 3.3 to 7.3 cm. At similar regurgitant orifice areas, driving pressures, and regurgitant flows, the measured color areas and aliasing distances were smallest in SJ valves, larger in MH valves, and largest in simple circular orifices. CONCLUSIONS. Large, complex regurgitant jets can be found in normal closed SJ and MH valves by color Doppler, although regurgitant flow volume is minimal. Jet size and velocity distribution differs markedly between SJ valves, MH valves, and circular orifices, even with comparable driving pressure, regurgitant orifice area, and regurgitant volume. The characteristic patterns of normal regurgitation must be recognized to avoid incorrect diagnoses of pathological regurgitation in SJ and MH prosthetic valves. MH valves should not be removed solely on the basis of a central regurgitant jet with a long aliasing distance. Peripheral jets in MH valves and all jets in SJ valves should be considered normal as long as no or only minimal aliasing is present. In contrast, peripheral jets with significant aliasing may represent strong evidence of pathological regurgitation.     

Determination of regurgitant fraction in isolated mitral or aortic regurgitation by pulsed Doppler two-dimensional echocardiography

Measurements of mitral and aortic valve flows were obtained with two-dimensional Doppler echocardiography in 25 patients with isolated mitral (n = 19) or aortic (n = 6) regurgitation and regurgitant fraction was calculated as the difference between the two flows divided by the flow through the regurgitant valve. Results were compared with measurements of regurgitant fraction determined by combined left ventricular angiography and thermodilution. Regurgitant fraction averaged 56 +/- 18% (range 19 to 79) by Doppler echocardiography and 48 +/- 17% (range 13 to 72) by angiography. A significant correlation was observed between the two methods (r = 0.91; SEE = 7%). In contrast, no significant correlation was found between regurgitant fraction measured by either method and the angiographic 1+ to 4+ qualitative classification of regurgitation. Doppler echocardiography appears to be an accurate method for the non-invasive quantification of severity of regurgitation in isolated left-sided valve lesions.     

Impact of impinging wall jet on color Doppler quantification of mitral regurgitation

BACKGROUND. In clinical color Doppler examinations, mitral regurgitant jets are often observed to impinge on the left atrial wall immediately beyond the mitral valve. In accordance with fluid dynamics theory, we hypothesized that a jet impinging on a wall would lose momentum more rapidly, undergo spatial distortion, and thus have a different observed jet area from that of a free jet with an identical flow rate. METHODS AND RESULTS. To test this hypothesis in vivo, we studied 44 patients with mitral regurgitation--30 with centrally directed free jets and 14 with eccentrically directed impinging wall jets. Maximal color jet areas (cm2) (with and without correction for left atrial size) were correlated with mitral regurgitant volumes, flow rates, and fractions derived from pulsed Doppler mitral and aortic forward flows. The groups were compared by analysis of covariance. Mean +/- SD mitral regurgitant fraction, regurgitant volume, and mean flow rate averaged 37 +/- 17%, 3.06 +/- 2.65 l/min, and 147 +/- 118 ml/sec, respectively. The maximal jet area from color Doppler imaging correlated relatively well with the mitral regurgitant fraction in the patients with free mitral regurgitant jets (r = 0.74, p less than 0.0001) but poorly in the patients with impinging wall jets (r = 0.42, p = NS). Although the mitral regurgitant fraction was larger (p less than 0.05) in patients with wall jets (44 +/- 20%) than in those with free jets (33 +/- 15%), the maximal jet area was significantly smaller (4.78 +/- 2.87 cm2 for wall jets versus 9.17 +/- 6.45 cm2 for free jets, p less than 0.01). For the same regurgitant fraction, wall jets were only approximately 40% of the size of a corresponding free jet, a difference confirmed by analysis of covariance (p less than 0.0001). CONCLUSIONS. Patients with mitral regurgitation frequently have jets that impinge on the left atrial wall close to the mitral valve. Such impinging wall jets are less predictable and usually have much smaller color Doppler areas in conventional echocardiographic views than do free jets of similar regurgitant severity. Jet morphology should be considered in the semiquantitative interpretation of mitral regurgitation by Doppler color flow mapping. Future studies of the three-dimensional morphology of wall jets may aid in their assessment.     

Quantitation of Doppler color flow jet areas for mitral regurgitation in children: angiographic correlation.

Eighteen patients with chronic isolated rheumatic mitral regurgitation aged between 7 and 19 years (mean age +/-SD, 12.69+/-3.47 years) were analyzed with color Doppler imaging. Sixteen patients were performed cardiac catheterization within 24 h. Jets were classified as eccentric and central. Regurgitant jet area and its ratio to left atrial area and body surface area were measured by Doppler color flow imaging. Regurgitant volume and regurgitant fractions were calculated with angiography. There was a good correlation between regurgitant jet area and angiographic grade of mitral regurgitation (P<0.01). The correlation between regurgitant jet area/left atrial area ratios and angiographic grade of mitral regurgitation was limited (P<0.01). There was excellent correlation between regurgitant jet area/body surface area and angiographic regurgitant fraction (r = 0.85; P<0.001). There was also a good correlation between regurgitant jet area and regurgitant fraction (r = 0.82; P<0.001). However, the relation of regurgitant jet area/left atrial area to regurgitant fraction was weak (r = 0.72; P<0.01). In conclusion, the measurement of regurgitant fraction and its ratios to left atrial area and body surface area by color Doppler flow imaging can predict the angiographic severity in children who have even eccentric regurgitant jets.     

Three-dimensional echocardiographic planimetry of maximal regurgitant orifice area in myxomatous mitral regurgitation: intraoperative comparison with proximal flow convergence

Objectives. We sought to validate direct planimetry of mitral regurgitant orifice area from three-dimensional echocardiographic reconstructions.Background. Regurgitant orifice area (ROA) is an important measure of the severity of mitral regurgitation (MR) that up to now has been calculated from hemodynamic data rather than measured directly. We hypothesized that improved spatial resolution of the mitral valve (MV) with three-dimensional (3D) echo might allow accurate planimetry of ROA.Methods. We reconstructed the MV using 3D echo with 3° rotational acquisitions (TomTec) using a transesophageal (TEE) multiplane probe in 15 patients undergoing MV repair (age 59 ± 11 years). One observer reconstructed the prolapsing mitral leaflet in a left atrial plane parallel to the ROA and planimetered the two-dimensional (2D) projection of the maximal ROA. A second observer, blinded to the results of the first, calculated maximal ROA using the proximal convergence method defined as maximal flow rate (2πr²v_a, where r is the radius of a color alias contour with velocity v_a) divided by regurgitant peak velocity (obtained by continuous wave [CW] Doppler) and corrected as necessary for proximal flow constraint.Results. Maximal ROA was 0.79 ± 0.39 (mean ± SD) cm²by 3D and 0.86 ± 0.42 cm²by proximal convergence (p = NS). Maximal ROA by 3D echo (y) was highly correlated with the corresponding flow measurement (x) (y = 0.87x + 0.03, r = 0.95, p < 0.001) with close agreement seen (ΔROA (y − x) = 0.07 ± 0.12 cm²).Conclusions. 3D echo imaging of the MV allows direct visualization and planimetry of the ROA in patients with severe MR with good agreement to flow-based proximal convergence measurements.     

Non-invasive measurement of the regurgitant fraction by pulsed Doppler echocardiography in isolated pure mitral regurgitation.

OBJECTIVE--To assess the usefulness of pulsed Doppler echocardiography as a method of measuring the regurgitant fraction in patients with mitral regurgitation. PATIENTS AND METHODS--Twenty controls and 27 patients with isolated mitral regurgitation underwent Doppler studies. In the patients the study was performed within 48 hours of cardiac catheterisation. Aortic outflow was measured in the centre of the aortic annulus, and mitral inflow was derived from the flow velocity at the tip of the leaflets and the area of the elliptical mitral opening. The regurgitant fraction was calculated as the difference between the two flows divided by the mtiral inflow. RESULTS--In the 20 controls the two flows were almost identical (mitral inflow, 4.44 (SD 0.88) l/min; aortic outflow, 4.58 (SD 0.84) l/min), with a mean regurgitant fraction of 4.2 (SD 8.4)%. In patients with mitral regurgitation, the mitral inflow was significantly higher than the aortic outflow (8.8 (3.6) v 4.3 (1.1) l/min). In most patients the Doppler-derived regurgitant fraction (45.8 (19.2)%) accorded closely with the regurgitant fraction (41.3 (SD 17.8)%) determined by the haemodynamic technique. CONCLUSION--Pulsed Doppler echocardiography, with an instantaneous velocity-valve area method for calculating mitral inflow, reliably measured the severity of regurgitation in patients with mitral regurgitation.