A simplified method for determining regurgitant fraction by Doppler echocardiography in patients with aortic regurtitation

Objectives. This study attempted to develop and validate a simple method for calculating aortic regurgitant fraction by use of pulsed wave Doppler echocardiography.Background. Although several investigators have been able to determine aortic regurgitant fraction by Doppler echocardiography, the methods used require accurate determination of the cross-sectional areas of intracardiac sites at which the volumetric flow is calculated.Methods. Our concept was based on a constant relation that exists between the cross-sectional area of the left ventricular outflow tract and the mitral valve annulus in normal subjects. To verify this, we used Doppler echocardiography to measure the flow velocity integral of the left ventricular outflow tract and the mitral annulus in the apical view in 50 normal subjects (32 men, 18 women, mean age 34 years).Results. Close correlation (r = 0.95) was observed between the flow velocity integral (FVI) of the outflow tract (OT) and that of the mitral annulus (MA): FVI_MA/FVI_OT= 0.77. Because mitral flow equals aortic flow in normal subjects, the ratio of the cross-sectional area of the mitral annulus to that of the outflow tract was 1/0.77. In patients with aortic regurgitation, the regurgitant fraction (RF) = (Aortic flow − Mitral flow)/Aortic flow = 1 − Mitral flow/Aortic flow. Substituting 0.77 for the area component of flow, RF = 1 − (1/0.77) · (FVI_MA/FVI_OT). To evaluate the accuracy of this method, we compared the regurgitant fraction derived by Doppler echocardiography with that from catheterization findings in 20 patients with aortic regurgitation (an isolated lesion was found in 14). The regurgitant fraction by catheterization was the difference between total (angiographic) and forward (thermodilution) stroke volumes as a percent of total flow. Good correlation was observed between catheterization and Doppler regurgitant fraction (r = 0.88, SEE 9%, p < 0.01).Conclusions. Thus, regurgitant fraction can be estimated from Doppler echocardiography in patients with aortic regurgitation by a method that requires only measurements of the flow velocity integral from the mitral annulus and left ventricular outflow tract.     

Measurement of aortic regurgitation by Doppler echocardiography

In an attempt to develop a new approach to the non-invasive measurement of aortic regurgitation, transmitral volumetric flow (MF) and left ventricular total stroke volume (SV) were measured by Doppler and cross sectional echocardiography in 23 patients without aortic valve disease (group A) and in 26 patients with aortic regurgitation (group B). The transmitral volumetric flow was obtained by multiplying the corrected mitral orifice area by the diastolic velocity integral, and the left ventricular total stroke volume was derived by subtracting the left ventricular end systolic volume from the end diastolic volume. The aortic regurgitant fraction (RF) was calculated as: RF = 1 - MF/SV. In group A there was a close agreement between the transmitral volumetric flow and the left ventricular total stroke volume, and the difference between the two measurements did not differ significantly from zero. In group B the left ventricular total stroke volume was significantly larger than the transmitral volumetric flow, and there was good agreement between the regurgitant fractions determined by Doppler echocardiography and radionuclide ventriculography. Discrepancies between the two techniques were found in patients with combined aortic and mitral regurgitation or a low angiographic left ventricular ejection fraction (less than 35%). The effective cardiac output measured by Doppler echocardiography accorded well with that measured by the Fick method. Doppler echocardiography provides a new and promising approach to the non-invasive measurement of aortic regurgitation.     

Measurement of aortic regurgitation by Doppler echocardiography.

In an attempt to develop a new approach to the non-invasive measurement of aortic regurgitation, transmitral volumetric flow (MF) and left ventricular total stroke volume (SV) were measured by Doppler and cross sectional echocardiography in 23 patients without aortic valve disease (group A) and in 26 patients with aortic regurgitation (group B). The transmitral volumetric flow was obtained by multiplying the corrected mitral orifice area by the diastolic velocity integral, and the left ventricular total stroke volume was derived by subtracting the left ventricular end systolic volume from the end diastolic volume. The aortic regurgitant fraction (RF) was calculated as: RF = 1 - MF/SV. In group A there was a close agreement between the transmitral volumetric flow and the left ventricular total stroke volume, and the difference between the two measurements did not differ significantly from zero. In group B the left ventricular total stroke volume was significantly larger than the transmitral volumetric flow, and there was good agreement between the regurgitant fractions determined by Doppler echocardiography and radionuclide ventriculography. Discrepancies between the two techniques were found in patients with combined aortic and mitral regurgitation or a low angiographic left ventricular ejection fraction (less than 35%). The effective cardiac output measured by Doppler echocardiography accorded well with that measured by the Fick method. Doppler echocardiography provides a new and promising approach to the non-invasive measurement of aortic regurgitation.     

A new approach to noninvasive evaluation of aortic regurgitant fraction by two-dimensional Doppler echocardiography

The aortic regurgitant fraction was estimated noninvasively in 20 patients with aortic regurgitation from systolic aortic and pulmonary volume flow determined by duplex Doppler echocardiography. By assuming that an excess of the aortic volume flow (AF) compared with the pulmonary volume flow (PF) is due to aortic regurgitant flow, the aortic regurgitant fraction (RF) was calculated as follows: RF(%) = (AF - PF)/AF X 100. The aortic and pulmonary volume flows were determined as products of systolic integrals of ejection flow velocities and cross-sectional areas of the left and right ventricular outflow tracts, respectively. The Doppler estimate of the regurgitant fraction was compared by semiquantitative grading (1+ to 4+) by cineaortography and with the measurement of regurgitant fraction by catheter technique. The mean Doppler-determined aortic regurgitant fraction was 2.4% for normal subjects, 28.0% for the patients with 1+, 32.6% for the patients with 2+, 53.3% for the patients with 3+, and 62.4% for the patients with 4+. A fair correlation was found between Doppler estimates of regurgitant fraction and semiquantitative cineaortographic grades (r = .80, p less than .01). In the patients without associated mitral regurgitation, a close correlation was observed between Doppler and catheter estimates of regurgitant fraction (r = .96, p less than .01; y = 1.0x - 0.08). In the patients with associated mild mitral regurgitation, however, Doppler estimates of regurgitant fraction substantially underestimated those determined by the conventional catheter technique, which cannot separately quantitate the aortic regurgitant fraction in the presence of mitral regurgitation. These observations indicate that the proposed Doppler technique provides a useful method to evaluate the aortic regurgitant fraction specifically regardless of the presence of associated mitral lesions.     

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.     

Measurement of mitral regurgitation by Doppler echocardiography.

In an attempt to develop a new approach to the non-invasive measurement of mitral regurgitation, Doppler echocardiography and left ventriculography were performed in 20 patients without valvar heart disease (group A) and in 30 patients with pure mitral regurgitation (group B). Volumetric flows through the aortic and the mitral orifices were determined by Doppler echocardiography. Aortic flow (AF) was calculated as the product of the aortic orifice area and the systolic velocity integral. The mitral flow (MF) was calculated as the product of the corrected mitral orifice area and the diastolic velocity integral. The mitral regurgitant fraction (RF) was calculated as RF = 1 - AF/MF. In group A aortic and mitral flow were very similar and the difference between the two did not differ significantly from zero. In group B the mitral flow was significantly larger than the aortic flow. There was a good correlation (r = 0.82) between the regurgitant fraction determined by Doppler echocardiography and the regurgitant grades determined by left ventriculography. The regurgitant fraction increased significantly with each grade of severity. These results show that Doppler echocardiography can be used to give a reliable measure of both aortic and mitral flow. This technique is a new and promising approach to the non-invasive measurement of mitral regurgitation.     

Noninvasive evaluation of the magnitude of aortic and mitral regurgitation by means of Doppler two-dimensional echocardiography

Using transmitral flow velocity and left ventricular ejection flow velocity, we measured left ventricular inflow volume (LVIV) and left ventricular outflow volume (LVOV) by pulsed Doppler echocardiography in 73 patients who had mitral valve regurgitation (MR), aortic valve regurgitation (AR), or no valvular regurgitation. Doppler-determined regurgitant volume (DOPRV), Doppler-determined regurgitant fraction (DOPRF), total stoke volume, and forward stroke volume were calculated to compare the severity assessed by angiographic scoring and the regurgitant fraction determined by radionuclide angiography (RIRF). In 17 patients with MR, LVIV (84.4 +/- 20.4 ml) was significantly greater (p less than 0.01) than LVOV (52.5 +/- 15.7 ml). LVOV, which is equivalent to forward stroke volume, was lower in patients with MR (52.2 +/- 15.7 ml) than in normal subjects (67.0 +/- 15.7 ml). In 15 patients with AR, LVOV (121.7 +/- 61.1 ml) was significantly greater (p less than 0.01) than LVIV (75.1 +/- 28.1 ml) and LVOV, which is equivalent to total stroke volume, was greater in patients with AR (121.7 +/- 61.1 ml) than in normal subjects (64.0 +/- 14.4 ml). DOPRF correlated with RIRF (r = 0.79, p less than 0.01, n = 11). DOPRV (mild: 10.5 +/- 8.5 ml; moderate: 28.8 +/- 13.6 ml; severe: 74.5 +/- 36.7 ml) and DOPRF (mild: 13.7% +/- 11.5%; moderate: 33.1% +/- 14.2%; severe: 52.6% +/- 15.3%) increased markedly with the severity of regurgitation as assessed by cineangiography. In AR, total stroke volume influenced both forward stroke volume and regurgitant volume, and in MR, regurgitant volume influenced both total stroke volume and forward stroke volume. Total stroke volume in AR and regurgitant volume in MR may play a key role in valvular regurgitation.     

Measurement of mitral regurgitation by Doppler echocardiography

In an attempt to develop a new approach to the non-invasive measurement of mitral regurgitation, Doppler echocardiography and left ventriculography were performed in 20 patients without valvar heart disease (group A) and in 30 patients with pure mitral regurgitation (group B). Volumetric flows through the aortic and the mitral orifices were determined by Doppler echocardiography. Aortic flow (AF) was calculated as the product of the aortic orifice area and the systolic velocity integral. The mitral flow (MF) was calculated as the product of the corrected mitral orifice area and the diastolic velocity integral. The mitral regurgitant fraction (RF) was calculated as RF = 1 - AF/MF. In group A aortic and mitral flow were very similar and the difference between the two did not differ significantly from zero. In group B the mitral flow was significantly larger than the aortic flow. There was a good correlation (r = 0.82) between the regurgitant fraction determined by Doppler echocardiography and the regurgitant grades determined by left ventriculography. The regurgitant fraction increased significantly with each grade of severity. These results show that Doppler echocardiography can be used to give a reliable measure of both aortic and mitral flow. This technique is a new and promising approach to the non-invasive measurement of mitral regurgitation.     

Quantification of regurgitant fraction in mitral regurgitation by cardiovascular magnetic resonance: comparison of techniques

BACKGROUND AND AIM OF THE STUDY: Cardiovascular magnetic resonance (CMR) assessment of mitral regurgitant volume from the subtraction of the right ventricular stroke volume (RVSV) from left ventricular stroke volume (LVSV) has commonly been performed using volumetric techniques. This is sensitive to errors in RVSV visualization and regurgitation of other heart valves, and therefore subtracting aortic flow volume from LVSV may be preferable. The study aim was to compare both techniques in a single CMR examination. METHODS: Twenty-eight patients with isolated mitral regurgitation underwent left ventricular (LV) and right ventricular (RV) volumetry and aortic flow volume measurements. Mitral regurgitant fraction (RF) was calculated as either RF(VOL) = [LVSV - RVSV] or RF(FLOW) = [LVSV - aortic flow volume], both expressed as a fraction of LVSV. The agreement of the measurements was assessed as a measure of robustness in clinical practice. RESULTS: There was good agreement between aortic and pulmonary flow (mean +/- SD difference -0.8 +/- 8.1 ml), and aortic flow volume and RVSV by volumetry (mean difference -2.6 +/- 11.8 ml). Intra- and interobserver variability (SD) of aortic flow volume (+/-6.6 ml and +/-5.3 ml) was superior to that of the RVSV (+/-8.5 ml and +/-12 ml). The intra- and inter-observer variability (SD) of RF(FLOW) was lower (+/-4.8% and +/-7.7%) than by RF(VOL) (+/-6.7% and +/-8.8%). CONCLUSION: The RF(FLOW) technique maximized intra- and inter-observer agreement, and is the optimal CMR technique to quantify mitral regurgitation. RF(FLOW) also has the advantage of allowing correction for aortic regurgitation when it is present, and is potentially independent of the effects of tricuspid and pulmonary regurgitation.     

Noninvasive quantification of mitral regurgitation in dilated cardiomyopathy: correlation of two Doppler echocardiographic methods

The presence and severity of functional mitral regurgitation were quantified by Doppler echocardiography in 17 patients with dilated cardiomyopathy and no evidence of primary valvular disease. Mitral regurgitant fraction was greater than 20% in 11 of the 17 patients, and exceeded 40% in four patients. Total stroke volume, calculated from the difference between end-diastolic and end-systolic volumes obtained by two-dimensional echocardiography, correlated well with mitral valve inflow determined by Doppler echocardiography (r = 0.90, p less than 0.001). Similarly, mitral regurgitant volume, calculated as the difference between echocardiographic total stroke volume and forward aortic volume obtained by Doppler echocardiography, correlated well with regurgitant volume calculated as the difference between mitral valve inflow and forward aortic flow, both determined by Doppler echocardiography (r = 0.90, p less than 0.001). Accordingly, functional mitral regurgitation can be conveniently demonstrated in patients with dilated cardiomyopathy by two different Doppler echocardiography methods, whose results are closely correlated. Mitral regurgitant fraction is greater than 20% in two thirds of the patients with a dilated cardiomyopathy.     

Quantitation of mitral regurgitation by Doppler echocardiography

The evaluation and care of patients with mitral regurgitation would be facilitated by an easy, reproducible and noninvasive method that could quantitate the hemodynamic burden. In this study, we describe a new Doppler echocardiographic method that measures the regurgitant fraction and we compare it with angiographic and scintigraphic methods. A total of 27 patients with mitral regurgitation were evaluated by echocardiography and either cardiac catheterization or scintigraphy. With two-dimensional echocardiography, diastolic and systolic volumes were measured to derive the left ventricular stroke volume (LVSV). The forward stroke volume (FSV) was obtained from the product of M mode-derived aortic valve area and ascending aortic flow velocity integral assessed by continuous-wave Doppler. Regurgitant fraction was calculated as follows: (LVSV - FSV)/LVSV. Comparisons showed that regurgitant fraction calculated by Doppler echocardiography correlated with regurgitant fraction determined by both cardiac catheterization (r = .82) and by scintigraphy (r = .89). There was, however, an important interobserver variability within each method: 10%, 13%, and 11% for Doppler echocardiography, angiography, and scintigraphy, respectively. In conclusion, Doppler echocardiography can be used to quantitate mitral regurgitation. Serial noninvasive determinations of regurgitant fraction may be useful in the evaluation of therapy and in the follow-up of patients with mitral insufficiency.     

Cross-sectional visualization of regurgitant jet by color flow mapping to evaluate aortic regurgitation

In the noninvasive evaluation of aortic regurgitation by Doppler echocardiography, flow mapping of the aortic regurgitant jet using the long-axis approach is of limited value in cases of combined mitral stenotic lesions. This is because the transmitral flow yields flow disturbances in the left ventricle, making it difficult to identify the extent of the aortic regurgitant jet. To overcome these limitations, the severity of aortic regurgitation was evaluated using the cross-sectional area of the aortic regurgitant jet at the level of the aortic valve as visualized by color flow imaging technique. The study population consisted of 16 patients with aortic regurgitation (10 with pure aortic regurgitation, five with superimposed mitral stenosis, and one with mitral valve replacement). Three normal subjects served as controls. The cross-section of the aortic regurgitant jet was visualized as a mosaic of yellow and blue in all patients with aortic regurgitation, but not in any of the controls. Planimetric measurements of the cross-sectional area of the regurgitant jet (J) and the aortic annulus area (Ao) were performed, and the Doppler parameter, J/Ao, was calculated. As a reference, the aortic regurgitant fraction (RF) was calculated from Doppler measurements of systolic aortic and pulmonary flows (AF and PF); RF (%) = (AF - RF)/AF x 100. The Doppler parameter, J/Ao, correlated well with the Doppler measurement of RF (r = 0.82, p less than 0.005), irrespective of the presence of associated mitral lesions. Thus, the cross-sectional area of the aortic regurgitant jet determined by color flow imaging technique would be a useful estimate of the severity of aortic regurgitation, even in the presence of associated mitral stenotic changes.     

End diastolic flow velocity just beneath the aortic isthmus assessed by pulsed Doppler echocardiography: a new predictor of the aortic regurgitant fraction

End diastolic flow velocity just beneath the aortic isthmus was measured within 72 hours of cardiac catheterisation by pulsed Doppler echocardiography in 30 controls and 61 patients with aortic regurgitation. The end diastolic flow velocity was determined at the peak R wave on a simultaneously recorded electrocardiogram. In all controls there was no reverse flow at the end diastole beneath the aortic isthmus. In patients with aortic regurgitation the end diastolic flow velocity correlated well with the angiographic grade of regurgitation (r = 0.81) and regurgitant fraction (r = 0.82). The mean (SD) values were 6.3 (5.2), 12.2 (4.3), 22.1 (5.7), and 34.3 (9.3) cm/s for patients with regurgitant fraction of less than 20%, between 20% and 40%, between 41% and 60%, and greater than 60%, respectively. An end diastolic flow velocity of greater than 18 cm/s predicted a regurgitant fraction of greater than or equal to 40% with a sensitivity of 88.5% and a specificity of 96%. The study suggests that the pulsed Doppler derived end diastolic flow velocity is a useful index in the routine non-invasive assessment of the severity of aortic regurgitation.     

End diastolic flow velocity just beneath the aortic isthmus assessed by pulsed Doppler echocardiography: a new predictor of the aortic regurgitant fraction.

End diastolic flow velocity just beneath the aortic isthmus was measured within 72 hours of cardiac catheterisation by pulsed Doppler echocardiography in 30 controls and 61 patients with aortic regurgitation. The end diastolic flow velocity was determined at the peak R wave on a simultaneously recorded electrocardiogram. In all controls there was no reverse flow at the end diastole beneath the aortic isthmus. In patients with aortic regurgitation the end diastolic flow velocity correlated well with the angiographic grade of regurgitation (r = 0.81) and regurgitant fraction (r = 0.82). The mean (SD) values were 6.3 (5.2), 12.2 (4.3), 22.1 (5.7), and 34.3 (9.3) cm/s for patients with regurgitant fraction of less than 20%, between 20% and 40%, between 41% and 60%, and greater than 60%, respectively. An end diastolic flow velocity of greater than 18 cm/s predicted a regurgitant fraction of greater than or equal to 40% with a sensitivity of 88.5% and a specificity of 96%. The study suggests that the pulsed Doppler derived end diastolic flow velocity is a useful index in the routine non-invasive assessment of the severity of aortic regurgitation.     

Doppler techniques in the detection of valvular regurgitation: their value and limitations

To evaluate the clinical value of various Doppler techniques in detecting valvular regurgitation, we compared the sensitivity, timing and duration of regurgitation, and the peak velocity of regurgitant signals among conventional pulsed Doppler, color Doppler, continuous wave Doppler and HPRF Doppler echocardiography. 1. Sensitivity of Doppler techniques in detecting mitral regurgitation: Among fifty patients with mitral regurgitation confirmed by left ventriculography, mitral regurgitation was detected in 48 (96%) using color Doppler and pulsed Doppler echocardiography; in 41 (82%) by HPRF Doppler; and in 37 (74%) by continuous wave Doppler echocardiography. In 103 consecutive normal volunteers, mitral regurgitant signals were detected in 46 (45%) by color Doppler, in 39 (38%) by pulsed Doppler, in 16 (16%) by HPRF Doppler, and in 8 (8%) by continuous wave Doppler echocardiography. 2. Timing and duration of regurgitant signals: To assess the timing and duration of regurgitant signals, 43 patients with regurgitant signals of short duration during systole or diastole were studied using M-mode color Doppler echocardiography. Using the latter method, regurgitant signals throughout systole and the isovolumic relaxation period could be demonstrated in all but four patients who had regurgitant signals of short duration during systole, but suggesting mitral or tricuspid regurgitation. In all patients with regurgitant signals of short duration during diastole, aortic or pulmonary regurgitant signals throughout diastole could be demonstrated with M-mode color Doppler echocardiography. Thus, this technique is superior to conventional pulsed Doppler echocardiography for detecting accurate timing and duration of valvular regurgitation. 3. Peak velocity of regurgitant flow: To compare the peak velocity of regurgitant flow by continuous wave Doppler and by HPRF Doppler echocardiography, 20 patients with mitral regurgitation and 22 patients with tricuspid regurgitation were examined using the both methods. In patients with severe mitral regurgitation, the peak velocity detected by HPRF Doppler echocardiography correlated well (r = 0.96) with that detected by continuous wave Doppler echocardiography. However, in patients with mild mitral regurgitation, the peak velocity detected by HPRF Doppler echocardiography was higher than that detected by continuous wave Doppler echocardiography. In patients with severe tricuspid regurgitation, the peak velocity had a close correlation (r = 0.99) with the both techniques. In patients with mild tricuspid regurgitation, the peak velocity was higher by HPRF than by continuous wave Doppler echocardiography. In conclusion, color or pulsed Doppler echocardiography should be used for detecting valvular regurgitation. M-mode color Doppler echocardiography is superior to conventional pulsed Doppler echocardiography for detecting timing and duration of valvular regurgitation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Quantification of aortic regurgitation with amplitude-weighted mean flow velocity from continuous wave Doppler spectra

Aortic regurgitant fraction (RFao) was quantified by estimating the ratio of the forward blood flow through the aortic (Qao) and pulmonary (Qp) valve: RFao = 100(Qao - Qp)/Qao. Aortic and pulmonary flow were measured by the systolic time integrals of the amplitude-weighted mean velocity from continuous wave Doppler spectra recorded over the aortic and pulmonary valves. Thus, measurements are independent of the left and right ventricular outflow tract area. In 20 normal subjects, aortic regurgitant fraction ranged between -2.9% and +12.0% (mean +4.3%), the physiologic value being +2%. In 20 patients with pure aortic regurgitation, aortic regurgitant fraction obtained by Doppler spectra (y) was compared with that calculated from biplane left ventriculography and cardiac output determined with the Fick method (x). The correlation was r = 0.94, (SEE = 5.4%, which is 10.6% of the angiography-Fick mean value). The regression line was y = 0.87x + 6.6 (mean y = 51.2%, mean x = 51.1%). It is concluded that determination of aortic regurgitant fraction in pure aortic regurgitation by using the amplitude-weighted mean velocity from continuous wave Doppler spectra is accurate and allows easy noninvasive evaluation of the regurgitant fraction in routine clinical applications.     

Color Doppler regurgitant jet area for evaluating eccenteric 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 vwave 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.     

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.     

Time variation of mitral regurgitant flow in patients with dilated cardiomyopathy

Angiographic results in patients with mitral regurgitation suggest that up to 50% of the regurgitant volume occurs during the preejection period. This contrasts markedly with the electromagnetic measurements of mitral regurgitant flow in anesthetized dogs, which suggest that only 5% of mitral regurgitant flow occurs during the preejection period. Therefore, we used two-dimensional and Doppler echocardiography to quantify mitral regurgitation during aortic ejection and in the preejection and postejection periods in eight patients with severe heart failure. Mitral regurgitant volume (RV) was calculated as the difference between total stroke volume (by two-dimensional echocardiography) and forward aortic flow (by pulsed Doppler). Regurgitant velocity (V) and time (RT) were measured by continuous-wave Doppler, and the mean regurgitant area (RAm) was calculated from the RT and mean regurgitant velocity (Vm): RAm = (RV/RT)/Vm. As a first approximation, the RA was assumed to be constant during systole, and the regurgitant volume during aortic ejection and during the preejection and postejection periods was calculated from: RVi = (Vmi) (RTi) (TAm), where Ti represents the duration of the appropriate period. Percentages of total regurgitant volume occurring during the preejection, ejection, and postejection periods were 13 +/- 4%, 79 +/- 5%, and 8 +/- 5%, respectively. Thus, in contrast to previously reported angiographic studies, mitral regurgitation occurs predominantly during the aortic ejection period. These results were not substantially changed by assuming a 20% reduction in effective regurgitant orifice area between the preejection and ejection periods and are consistent with data from chronically instrumented dogs with mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.