Doppler echocardiography diagnosis and classification of the degree of aortic valve insufficiency in patients with aortic stenoses and mitral valve diseases

To test the capacity of pulsed Doppler echocardiography in the detection and quantification of aortic regurgitation, 64 consecutive patients with aortic and mitral valve disease were examined clinically and by echocardiography before cardiac catheterization. The severity of aortic regurgitation was determined angiographically (I-IV) and compared with the extent of the regurgitant jet in the left ventricle measured by pulsed Doppler echocardiography. In 15 of 64 patients neither angiography nor pulsed Doppler echocardiography showed aortic regurgitation (specificity 100%). Apart from 3 patients with poor echo quality pulsed Doppler echocardiography correctly detected aortic regurgitation in 46 of 49 patients (sensitivity 94%). Clinical examination (63%) and M-mode echocardiography (63%) were significantly less sensitive than Doppler echocardiography (p less than 0.001). The pulsed Doppler echocardiographic degree of aortic regurgitation correlated strongly with angiography (corrected contingency coefficient 0.91). In patients with severe aortic stenosis (systolic gradient greater than 50 mm Hg) aortic regurgitation I was slightly overestimated by pulsed Doppler echocardiography (p less than 0.003). Differentiation of aortic regurgitation III and IV was not possible. Mitral valve disease did not affect quantification of aortic regurgitation (n = 23).     

Measurement of isovolumic relaxation: comparison of echocardiographic mitral valve opening and Doppler mitral valve flow

The relation between mitral valve opening and transmitral blood flow was investigated by M-mode echocardiography and Doppler ultrasound in 50 normal subjects to allow the measurement of the timing of the end of isovolumic relaxation. Standard parasternal M-mode echocardiograms of the mitral valve to show the onset of cusp separation were recorded with a simultaneous electrocardiogram and phonocardiogram. Pulse wave Doppler ultrasound using both amplitude and spectral analysis was recorded with a transducer at the apex, and the initial diastolic blood flow towards the transducer was taken as the onset of flow. For each subject five cardiac cycles of similar length were measured using the three methods. Isovolumic relaxation could be measured with a high degree of reliability (retest reliability coefficient greater than 0.94). The echocardiographic measurement of isovolumic relaxation ranged from 52 to 82 ms (mean(SD) 67(9) ms). Isovolumic relaxation measured by Doppler was 52-83 ms (mean(SD) 67(9) ms) using amplitude analysis and 54-89 ms (mean(SD) 72(11) ms) using spectral analysis. There was a strong correlation between the echocardiographic isovolumic relaxation and measurements made using spectral analysis (r = 0.93, slope 0.97) and amplitude analysis (r = 0.97, slope 0.98). Therefore in normal subjects the end of isovolumic relaxation can be reliably measured by echocardiographic and Doppler methods, and whereas the amplitude signal is coincidental with that measured by echocardiography that measured by spectral analysis is delayed by approximately 5 ms.     

Clinical significance of Doppler echocardiographic determination of the severity of aortic valve stenoses

The purpose of the study was to evaluate the clinical significance of Doppler echocardiography in the determination of the severity of aortic stenosis, in particular, to determine to what extent a therapeutic decision in the individual patient is possible solely on the basis of noninvasive investigations. Forty consecutive patients (mean age 53 +/- 13 years, 58% males) with suspected aortic valve disease of purely or mainly stenotic nature, were examined by two-dimensional echocardiography and continuous-wave Doppler echocardiography on average 48 h before cardiac catheterization. An adequate Doppler registration was obtained in 93% (37/40). In 59% the right sternal border proved to be the best window. The gradient determined in the Doppler examination correlated well with the maximum catheter gradient (r = 0.95; SYX +/- 6.2 mm Hg; p less than 0.0005) and with the peak-to-peak catheter gradient (r = 0.93; SYX +/- 6.0 mm Hg; p less than 0.0005). However, in the individual case, clinical assessment on the basis of the Doppler gradient alone proved to be misleading. This was the case in early systolic gradients (aortic incompetence, high cardiac output) or in pronounced left ventricular dysfunction. However, additional consideration of the ratio time to peak velocity (Vmax)/left ventricular ejection time (LVET) (criterion for operation greater than 0.35) and of the echocardiographically determined ejection fraction, enabled us to make the same therapeutic decision in all 37 patients (17 conservative, 20 operative) as that made following the result of cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)     

Accurate noninvasive quantification of stenotic aortic valve area by Doppler echocardiography

Laminar flow through a conduit is equal to the mean velocity times the cross-sectional area of the orifice. Therefore, volume is equal to the time-velocity integral multiplied by the cross-sectional area. In aortic stenosis, flow in the stenotic jet is laminar and the aortic valve area should be equal to the volume of blood ejected through the valve divided by the time-velocity integral of the aortic jet velocity recorded by continuous-wave Doppler echocardiography. To test whether this concept can be used to accurately determine aortic valve area noninvasively by the Doppler method, 39 patients (age 35 to 82 years, mean 63) underwent pulsed Doppler combined with two-dimensional echocardiography for measurement of stroke volume at the aortic, pulmonic, and mitral anulus as well as continuous-wave Doppler recording of the aortic jet. Aortic valve area determined at cardiac catheterization by the Gorlin equation ranged between 0.4 and 2.07 cm2 (mean 0.89 +/- 0.45). Doppler-derived valve area, determined with the stroke volume value from either the aortic, pulmonic, or mitral anulus, correlated well with the area determined at cardiac catheterization (r = .95, .97, and .96, respectively). A simplified method for measuring aortic valve area derived as the cross-sectional area of the aortic anulus times peak velocity just proximal to the aortic valve divided by peak aortic jet velocity correlated well with measurements obtained at cardiac catheterization (r = .94). An excellent separation between critical and noncritical aortic stenosis was seen using either one of the Doppler methods.(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive quantification of the aortic valve area in aortic stenosis by Doppler echocardiography

To develop a noninvasive approach to the quantification of thestenotic aortic valve area, Doppler echocardiography and cardiaccatheterisation were performed in 24 patients with pure aorticstenosis. The transmitral volumetric flow was measured by Dopplerechocardiography and calculated as the product of the correctedmitral orifice area (CM A) and the diastolic velocity integral(DVI). The maximal aortic jet velocities were recorded by Dopplertechnique and integrated to obtain the systolic velocity integral(SVl). Assuming that the aortic and mitral volumetric flowsare equal, the aortic valve area (A VA) was calculated as: AVA= CM A x DVI/SVI. Mean pressure gradient and cardiac outputwere measured during catheterisation and the aortic valve areawas calculated by the Gorlin formula. Comparison between theaortic valve area determined by Doppler technique and catheterisationyielded a close correlation (r = 0.92, P<0.001), and therewas no significant difference between the two measurements.Good correlations of the instantaneous pressure gradient andthe stroke volume were also obtained between the two techniques(r = 0.91 and r = 0.90, respectively, P<0.001). These resultsdemonstrate that our Doppler echocardiographic method providesa promising approach to the noninvasive quantification of theaortic valve area in aortic stenosis     

Color Doppler echocardiography and radionuclide ventriculography in aortic and mitral valve insufficiency

In 99 stable patients with auscultatory findings of aortic (n = 52) or mitral regurgitation (n = 47), the regurgitant fraction was determined by radionuclide ventriculography (RNV). In addition, color-coded Doppler echocardiography (CDE) was performed to assess semi-quantitatively the severity of valve incompetence. In aortic regurgitation, the results of both methods concurred in 73% of cases. With CDE, the regurgitation was underestimated in 10% by one class and overestimated in 17% by one class. In mitral regurgitation the results concurred only in 60% of the patients. CDE seemed to overestimate the incompetence, by one class, in 19% and to underestimate the lesion in 21% of the patients. In 2/47 patients the difference was more than one class. In conclusion, both noninvasive methods are applicable to assess the severity of mitral and aortic regurgitation. The RNV appears superior in follow-up assessment because of a slightly better reproducibility and investigator-independence.     

Doppler echocardiographic assessment of hemodynamic progression of valvular aortic stenosis over time: comparison between aortic valve resistance and valve area.

BACKGROUND: Doppler-derived aortic valve resistance (AVR), i.e. the ratio between pressure gradient and flow rate, has been proposed as an alternative parameter to valve area (AVA) for assessing the hemodynamic severity of aortic stenosis (AS). There are no data on the evaluation of hemodynamic progression of AS using AVR. METHODS: Forty-five adult patients (24 women and 21 men, mean age 72 +/- 10 years) with AS were followed up for 18 months (range 6 to 45 months) with serial Doppler-derived AVR (Isaaz, JACC 1991; 18: 1661) and AVA (continuity equation). Rates of change of AVR and AVA over time were indexed for year of follow-up; furthermore, variations of these parameters during follow-up were expressed as percent change from baseline. RESULTS: During the follow-up period, AVA decreased from 0.74 +/- 0.28 to 0.6 +/- 0.17 cm2 (p < 0.05), with a rate of change of -0.1 +/- 0.13 cm2/year; AVR increased from 349 +/- 187 to 462 +/- 180 dyne/s/cm-5 (p < 0.05), with a rate of change of 79 +/- 69 dyne/s/cm-5/year. Variations observed in AVR, expressed as percent change from baseline, were larger than those observed in AVA (51 +/- 62% versus -16.5 +/- 15%). AVR percent change from baseline significantly correlated with AVA percent change from baseline (r = 0.83, p < 0.05). During follow-up, 6 patients showed no change in AVA: AVR was unchanged in 3 and increased in the remaining 3 patients (6, 11 and 58%, respectively), indicating a progression of AS severity that could not be appreciated from AVA alone. CONCLUSIONS: Serial changes in AVR, as assessed by Doppler echocardiography, significantly correlate with changes in AVA. Thus, the noninvasive assessment of AVR may be utilized in the evaluation of hemodynamic progression of AS and, in conjunction with AVA, may also provide complementary information for the management of these patients.     

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.     

Assessment of pulsed Doppler echocardiography in detection and quantification of aortic and mitral regurgitation.

Pulsed Doppler echocardiography was employed to detect disturbed or turbulent flow diagnostic of aortic or mitral regurgitation. Sensitivity, specificity, diagnostic accuracy, and predictive value were assessed by the independent interpretation and comparison of aortic root angiograms (91 patients) and left ventriculograms (94 patients) to the time interval histogram display of the pulsed Doppler. Sensitivity of Doppler in detecting mitral regurgitation was 94 per cent, with specificity 89 per cent, predictive value 81 per cent, and diagnostic accuracy 90 per cent (32 patients with, 62 without regurgitation). In aortic regurgitation, sensitivity was also 94 per cent, specificity 82 per cent, predictive value 94 per cent, and the diagnostic accuracy was 91 per cent (69 patients with, 22 without aortic regurgitation). Additionally, no Doppler evidence of mitral or aortic regurgitation was present in 20 normal subjects. The aetiology of left-sided valvular regurgitation varied widely, with prosthetic valvular insufficiency being the cause of mitral and aortic regurgitation in seven and 10 patients, respectively. Sixteen of 17 (94%) paraprosthetic leaks were correctly identified by pulsed Doppler. In patients with aortic regurgitation the flow-velocity curve recorded in the ascending aorta frequently showed a negative (or reversed) diastolic component, the magnitude of which (expressed as percentage negative area) correlated significantly with angiographic severity of regurgitation. Thus, pulsed Doppler echocardiography is a highly accurate and objective non-invasive technique for detecting mitral and aortic regurgitation. In aortic regurgitation, estimation of severity is possible from inspection of the Doppler ascending aortic flow velocity curve.     

Ultrasonic aortic valve decalcification: serial Doppler echocardiographic follow-up

Serial two-dimensional and Doppler echocardiography was performed on 61 patients who had surgical ultrasonic aortic valve decalcification for calcific aortic stenosis. The mean patient age at the time of operation was 77.4 +/- 7.0 years; 93% had moderate to severe preoperative symptomatic limitation. Compared with preoperative studies, Doppler echocardiographic evaluation before hospital discharge revealed a significant reduction in the mean aortic valve pressure gradient (45.3 +/- 16.2 to 14.4 +/- 6.5 mm Hg, p less than 0.0001) and improvement in aortic valve area (0.62 +/- 0.17 to 1.33 +/- 0.33 cm2, p less than 0.0001). There was no initial change in aortic regurgitation grade. Follow-up Doppler echocardiographic evaluation was possible in 43 patients alive at 9.3 +/- 3.9 months. A small but statistically significant trend toward aortic restenosis was found; only one patient had severe restenosis. Severe aortic regurgitation had developed in 26% of patients and moderate aortic regurgitation in 37%. Aortic valve replacement was performed in six patients (14%) with severe symptomatic aortic regurgitation. Significant deficiency in central coaptation as a result of cusp scarification and retraction appeared to be the mechanism of postdecalcification regurgitation. Attempted salvage of the native aortic valve in severe calcific stenosis by ultrasonic decalcification adequately relieves stenosis but leads to an unacceptable incidence of significant aortic regurgitation at follow-up study.     

Color-guided Doppler echocardiographic assessment of aortic valve stenosis

The severity of valvular aortic stenosis was assessed by Doppler color flow mapping in 100 consecutive patients who underwent successful cardiac catheterization within 2 weeks of the Doppler study. The maximal width of the aortic stenosis jet seen in 61 of these patients (Group A) was measured at the aortic valve. Color-guided continuous wave Doppler examination was used to measure the mean transaortic pressure gradient, and the aortic valve area was estimated using the simplified continuity equation. The aortic stenosis jet was not seen in 39 patients (Group B), and the mean pressure gradient and aortic valve area in these patients were assessed by conventional Doppler echocardiography alone. The mean pressure gradient obtained by continuous wave Doppler study and cardiac catheterization in the 61 Group A patients correlated well (r = 0.90); the correlation was lower in the 39 Group B patients (r = 0.70). The overall correlation for the combined Groups A and B was good (r = 0.82). The aortic valve area estimated by continuous wave Doppler study and cardiac catheterization in 54 Group A patients correlated well (r = 0.92); the correlation in 22 Group B patients was lower (r = 0.71). The correlation for all 76 patients (Groups A and B) was good (r = 0.80). The maximal aortic stenosis jet width also correlated well with the aortic valve area estimated at catheterization in 54 patients (r = 0.90). Group C represented an additional 14 patients in whom the left ventricle could not be entered during cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)     

Non-invasive quantification of aortic regurgitation by Doppler echocardiography

This study was undertaken to assess the contribution of Doppler echocardiography to the quantification of aortic valve regurgitation. Ultrasound examination was performed by recording aortic arch blood flow from the suprasternal notch. A non-invasive index of valve regurgitation was obtained by calculating the ratio between the maximal amplitude of forward flow during systole and the amplitude of retrograde flow during diastole measured at the onset of the R wave of the electrocardiogram. This index was compared with semiquantitative data derived from supravalvular aortography in 93 patients. In pure aortic regurgitation (67 patients) the results showed a high correlation coefficient between Doppler and angiographic estimates. In cases of associated aortic valve stenosis there were problems in the accurate estimation of systolic blood flow which led to global overestimation in general of the degree of regurgitation and considerable lack of precision in individual patients. But in general Doppler echocardiography appeared to be a successful technique to quantify pure aortic regurgitation.     

Quantitative Doppler echocardiography diagnosis of congenital aortic and pulmonary artery stenoses

The aim of the present study was to check the value of cw-Doppler echocardiography for the assessment of severity of congenital aortic and pulmonary stenoses in children and adolescents. Over a period of 3 years 217 children and adolescents with aortic and 98 with pulmonary stenosis, resp., underwent echocardiography. In 21 patients with aortic and in 23 with pulmonary stenosis pressure gradients were determined by cw-Doppler as well as intracardiac pressure measurement. The comparison showed excellent accordance between both sorts of data for aortic stenoses (r = 0.939) and pulmonary stenosis (r = 0.969). These results show that Doppler echocardiography is a reliable diagnostic method for the determination of pressure gradients. Thus, it allows correct selection of children and adolescents with aortic stenosis for surgery. So far, 12 patients have been operated on without preoperative cardiac catheterization. Indication for balloon valvuloplasty in patients with valvular pulmonary stenosis can be based safely on 2 D- and Doppler echocardiography.     

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

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

A comparison between mitral and aortic outputs evaluated by Doppler echocardiography in a group of healthy subjects: false regurgitation

Doppler echocardiography is a potentially useful tool for the non invasive evaluation of cardiac output and, therefore, for the quantitative assessment of valvular regurgitation. The aim of our study was to establish the presence of possible pitfalls in the evaluation of mitral and aortic regurgitant fraction obtained by Doppler echocardiography comparing the cardiac output measured at the level of the mitral and aortic valve. For this purpose 19 healthy volunteers, aged between 14-68 years, were studied. Stroke volume and cardiac output were calculated at the level of the mitral and aortic valve. The methods we used for the measurement of both the mitral and aortic cardiac output had already been validated and presumes that the shape of the valve annulus, is circular. No statistically significant differences were found between the parameters obtained at the two different valvular levels. Furthermore, cardiac output values correlated fairly well (r = 0.83, ESS = 0.78 l/min). In 9 subjects the aortic cardiac output was greater than the mitral one, while in the others mitral cardiac output was greater. The average of the differences between the two cardiac outputs was 0.58 +/- 0.48 l/min with a regurgitation fraction of 9.5 +/- 7.9%. Our results show that the mitral and aortic stroke volume and cardiac output, as measured by Doppler echocardiography (considering a circular shaped valve annulus, are not statistically different and correlate fairly well in our normal subjects. Nevertheless, we observed a certain degree of variability between the mitral and the aortic cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)     

Doppler echocardiographic assessment of transmitral gradients and mitral valve area before and after mitral valve balloon dilatation

This is a comparative study of 60 sets of observations of mitral valve end-diastolic gradient, mean diastolic gradient, and mitral valve area obtained by Doppler echocardiography and cardiac catheterization. The studies were performed in 28 patients, 16 of whom underwent mitral valve balloon valvuloplasty. These 16 patients had studies performed before, immediately after valvuloplasty, and one week later. Thus 28 studies were performed before or without valvuloplasty (Group I) and 32 after valvuloplasty (Group II). The time interval between Doppler echocardiography and cardiac catheterization was less than 24 hours in 44 studies and 24 to 72 hours in 16 studies. In Doppler echocardiography the gradients were obtained by simplified Bernoulli's equation and the mitral valve area by pressure half-time method. There was excellent correlation between end-diastolic gradients (r = 0.96, p less than 0.001) and mean diastolic gradients (r = 0.92, p less than 0.001) measured by the two techniques. A statistically significant correlation also existed in the mitral valve area values (r = 0.53, p less than 0.005). On separate analysis Group I showed excellent correlation for all three variables (r values of 0.90, 0.87, and 0.82 for end-diastolic gradients, mean-diastolic gradients, and mitral valve area, respectively). Group II also showed excellent correlation of end-diastolic gradients (r = 0.80) and mean diastolic gradients (r = 0.87), but poor correlation of the mitral valve areas (r = 0.17; p = NS) by the two techniques. Doppler echocardiography can accurately measure transmitral gradients both before and after valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)     

Three-dimensional echocardiographic reconstruction of mitral valve color Doppler flow events

In vitro studies have suggested superior accuracy of 3-dimensional echocardiography over conventional methods for the characterization and quantitation of color Doppler flow events. Little in vivo work has been reported in this area; this study demonstrates the feasibility of 3-dimensional reconstruction of mitral valve flow events in an unselected group of adult patients and discusses optimal instrument settings for the acquisition of 3-dimensional datasets.