Detection of mild aortic regurgitation by range-gated pulsed doppler echocardiography

In order to assess the sensitivity and specificity of the range-gated pulsed Doppler echocardiogram for the detection of aortic regurgitation, a study with use of this technique was carried out in 46 patients. They were classified into 3 groups: Group I was composed of 19 patients with a variety of heart diseases but with a competent aortic valve. Cardiac catheterization revealed no aortic regurgitation in any of the 19 patients, and the Doppler echocardiogram detected no turbulent diastolic flow in the left ventricular outflow tract. Group II was composed of 17 patients who clinically and by auscultation had aortic regurgitation, which was confirmed by cardiac catheterization in 6. In all 17 patients the Doppler echocardiogram detected several grades of turbulent diastolic flow compatible with aortic regurgitation in the left ventricular outflow tract. Group III was composed of 10 patients with aortic regurgitation but without the expected clinical or auscultatory evidence. The echocardiogram detected mitral valve flutter in only 1 patient. Cardiac catheterization revealed aortic regurgitation graded $\text{1}\text{4}$ and $\text{2}\text{4}$ in 9 patients, and the patient who did not undergo catheterization had a murmur of aortic insufficiency 6 months later. In all 10 patients the Doppler echocardiogram detected a regurgitating turbulent flow compatible with aortic regurgitation in the left ventricular outflow tract.It is concluded that the Doppler echocardiogram was more useful than auscultation and echocardiography for the detection of mild aortic regurgitation. In this study the range-gated pulsed Doppler echocardiogram proved 100% sensitive and specific. However, it will be necessary to study larger groups in order to assess its utility in more complicated conditions (obesity, emphysema, and heart failure) and the differential diagnosis with other diastolic murmurs.     

Doppler echocardiographic measurement of aortic valve area in aortic stenosis: a noninvasive application of the Gorlin formula

Thirty adult patients with aortic stenosis had Doppler echocardiography within 1 day of cardiac catheterization. Noninvasive measurement of the mean transaortic pressure gradient was calculated by applying the simplified Bernoulli equation to the continuous wave Doppler transaortic velocity recording. Stroke volume was measured noninvasively by multiplying the systolic velocity integral of flow in the left ventricular outflow tract (obtained by pulsed Doppler ultrasonography) by the cross-sectional area of the left ventricular outflow tract (measured by two-dimensional echocardiography). Non-invasive measurement of aortic valve area was calculated by two methods. In method 1, the Gorlin equation was applied using Doppler-derived mean pressure gradient, cardiac output and systolic ejection period. Method 2 used the continuity equation. These noninvasive measurements were compared with invasive measurements using linear regression analysis, and mean pressure gradients correlated well (r = 0.92). Aortic valve area by either noninvasive method also correlated well with cardiac catheterization values (method 1, r = 0.87; method 2, r = 0.88). The sensitivity of Doppler detection of critical aortic stenosis was 0.86, with a specificity of 0.88 and a positive predictive value of 0.86. Cardiac output measured nonsimultaneously showed poor correlation (r = 0.51). Doppler echocardiography can distinguish critical from noncritical aortic stenosis with a high degree of accuracy. Measurement of aortic valve area aids interpretation of Doppler-derived mean pressure gradient data when the gradients are in an intermediate range (30 to 50 mm Hg).     

Determination of the stenotic aortic valve area in adults using Doppler echocardiography

The severity of aortic stenosis was evaluated by Doppler echocardiography in 48 adults (mean age 67 years) undergoing cardiac catheterization. Maximal Doppler systolic gradient correlated with peak to peak pressure gradient (r = 0.79, y = 0.63x + 25.2 mm Hg) and mean Doppler gradient correlated with mean pressure gradient (r = 0.77, y = 0.59x + 10.0 mm Hg) by manometry. The transvalvular pressure gradient is flow dependent, however, and associated left ventricular dysfunction was common in our patients (33%). Thus, of the 32 patients with an aortic valve area less than or equal to 1.0 cm2 at catheterization, 6 (19%) had a peak Doppler gradient less than 50 mm Hg. To take into account the influence of volume flow, aortic valve area was calculated as stroke volume, measured simultaneously by thermodilution, divided by the Doppler systolic velocity integral in the aortic jet. Aortic valve areas calculated by this method were compared with results at catheterization in the total group (r = 0.71). Significant aortic insufficiency was present in 71% of the population. In the subgroup without significant coexisting aortic insufficiency, closer agreement of valve area with catheterization was noted (n = 14, r = 0.91, y = 0.83x + 0.24 cm2). Transaortic stroke volume can be determined noninvasively by Doppler echocardiographic measures in the left ventricular outflow tract, just proximal to the stenotic valve. Aortic valve area can then be calculated as left ventricular outflow tract cross-sectional area times the systolic velocity integral of outflow tract flow, divided by the systolic velocity integral in the aortic jet.(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantification of aortic regurgitation using Doppler imaging

Summary Aortic insufficiency induces the development of a jet within the left ventricular outflow tract. The cross sectional area of this jet at its origin is the major determinant of the severity of the regurgitation. M mode Doppler imaging reportedly allows the measurement of jet diameter. This study was designed to evaluate the quantification of aortic regurgitation using a measurement of the jet diameter by M mode Doppler imaging. The left ventricular outflow tract of 32 patients was imaged using either a multigate pulsed Doppler velocimeter or color flow mapping system (Hewlett Packard). The jet diameter was compared to a 4 grade semiquantification derived from supravalvular aortography. Adequate imaging was obtained in the 32 patients. Four of them had no regurgitation: no diastolic flow image could be found during their Doppler investigation. A clear jet image was obtained in the 28 remaining patients. We found a close relationship between the jet diameter (jd in mm) and the angiographic grade (ag): jd = 2.4 + 6.1 ag, r = 0.88, the most significant differences being found between grade 0 and grade 1, and grade 1 and grade 2. In conclusion, direct M mode measurement of the regurgitant jet of aortic insufficiency at its origin offers an additional approach of the severity of the leak.     

M-mode and cross-sectional echocardiographic features of flail aortic leaflets

The echocardiographic features in seven patients with flail aortic leaflets are described and are correlated with the anatomical appearance of the valve at the time of surgery or autopsy. M-mode echocardiography showed coarse and "shaggy" diastolic echoes within the aortic root and thickening of the aortic leaflets during systole in all patients. Six patients had coarse and "shaggy" diastolic echoes within the left ventricular outflow tract in continuity with similar echoes within the aortic root. Cross-sectional echocardiography in three patients revealed a cord-like mass prolapsing into the left ventricular outflow tract during diastole. Three of the patients had no vegetations at the time of surgery. Both modes of echocardiography are of value in demonstrating abnormal echoes prolapsing into the left ventricular outflow tract, characteristic of flail aortic leaflets that can occur in the presence or absence of vegetations.     

Quantitative evaluation of aortic insufficiency by continuous wave Doppler echocardiography

To assess the usefulness of continuous wave Doppler echocardiography in the evaluation of aortic insufficiency, the aortic regurgitant flow velocity pattern obtained with continuous wave Doppler examination was compared with the results of aortography and conventional pulsed Doppler techniques in 25 individuals with aortic insufficiency. The diastolic deceleration slope as measured from the continuous wave tracing was significantly different among subgroups of patients with mild (1.6 +/- 0.5 m/s2), moderate (2.7 +/- 0.5 m/s2) and severe (4.7 +/- 1.5 m/s2) aortic insufficiency as determined from aortography. Deceleration slopes greater than 2 m/s2 separated individuals with moderate and severe insufficiency from those with mild insufficiency. Similar findings were seen when comparing the pressure half-time method of diastolic velocity decay with the more severe grades of aortic insufficiency exhibiting the shortest pressure half-times. There was also a high correlation (r = 0.85) between the deceleration slope measured by continuous wave Doppler recordings and the grade of insufficiency as assessed by pulsed Doppler echocardiography. End-diastolic velocities correlated poorly (r = 0.28) with catheter-measured end-diastolic pressure difference between the aorta and the left ventricle. These findings demonstrate that the aortic regurgitant flow pattern by continuous wave Doppler echocardiography may be useful in quantitating the degree of aortic insufficiency by assessing the rate with which aortic and left ventricular pressures equilibrate during diastole.     

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.     

Aortic regurgitation: evaluation by pulsed Doppler echocardiography

Ninety-one consecutive patients with aortic regurgitation, either isolated (23 subjects) or associated with other valvular diseases (68 subjects), were studied with pulsed Doppler echocardiography and subsequent aortography, and the results were compared in order to assess the value of the noninvasive technique for a semiquantitative evaluation of the degree of the aortic regurgitation. Both the noninvasive and invasive estimations were graded on a four-point scale. In the long-axis parasternal view, the outflow tract of the left ventricle was divided in four areas going from the aortic valve to the apex. Echo-Doppler grading (from + 1 to +4) was obtained by assessing the area where the abnormal diastolic flow could still be recorded. In the group as a whole, concordant degrees of the aortic insufficiency were obtained in 73 of 91 patients (r = .93; p less than .001); the degree of the aortic regurgitation was overestimated in 8 cases (9%) and underestimated in 10 cases (11%). Most of the discrepancies between the Doppler and the aortographic evaluation were found in patients with intermediate degree (+2, +3) of aortic regurgitation; the degree of discordance was never more than +1 or -1. Correlation between Doppler and aortography was higher in the subjects with pure aortic regurgitation (r = .94, p less than .001) and lower in the subgroup of the subjects with associated mitral stenosis (r = .87, p less than .001). Two-dimensional pulsed Doppler echocardiography is a simple and little time consuming technique that in selected groups of patients can be relied upon for the semiquantitated evaluation of the degree of aortic regurgitation.     

Pulsed doppler echocardiographic detection of right-sided valve regurgitation: Experimental results and clinical significance

Pulsed Doppler echocardiography may allow noninvasive detection of tricuspid insufficiency as disturbed or turbulent systolic flow in the right atrium and pulmonary insufficiency as turbulent diastolic flow in the right ventricular outflow tract. Accordingly, six open chest mongrel dogs were examined with Doppler echocardiography before and after surgical creation of tricuspid and pulmonary insufficiency. The Doppler technique detected the appropriate lesion in all instances, with a specificity of 100 percent.In 121 patients (20 without heart disease, 101 with heart disease of various causes), pulsed Doppler echocardiography was used to detect right-sided valve regurgitation. Results were compared with right-sided pressure measurements and M mode echocardiographic findings in all, and with right ventricular angiography in 21 patients. Pulsed Doppler study detected tricuspid insufficiency in 61 of 100 patients, 12 (20 percent) of whom had clinical evidence of this lesion. Angiographic evidence of tricuspid regurgitation was present in 18 patients, 17 of whom had positive Doppler findings (sensitivity 94 percent), and absent in 3, all with negative Doppler findings. Pulmonary insufficiency was found on pulsed Doppler study in 47 of 91 patients, 3 of whom (all after pulmonary valvotomy) had clinical evidence of this lesion. Increased right ventricular systolic pressure (greater than 35 mm Hg) was noted more often in patients with (55 of 61 or 90 percent) than in those without (22 of 59 or 37 percent) tricuspid insufficiency (p <0.01). Pulmonary arterial mean pressure was elevated (22 mm Hg or less) more often in patients with (38 of 43 or 88 percent) than in those without (24 of 64 or 38 percent) pulmonary insufficiency (p <0.01).Thus, pulsed Doppler echocardiography appears to be an accurate noninvasive technique for detection of right-sided valve regurgitation. The absence of diagnostic physical findings in many of the patients indicates that the hemodynamic severity of the Doppler-detected valve insufficiency was probably insignificant. However, because of its high incidence rate (87 percent) and association with pulmonary hypertension (87 percent), pulsed Doppler detection of tricuspid or pulmonary insufficiency, or both (in the absence of pulmonary stenosis) was found superior to M mode echocardiographic measurements (right ventricular size, pulmonary valve motion) in the prediction of pulmonary hypertension.     

In vitro measurement of stenotic human aortic valve orifice area in a pulsatile flow model. Validation of the continuity equation

Aortic valve orifice area estimation in patients with aortic stenosis may be obtained non-invasively using several Doppler echocardiographic methods. Their validity has been established by correlation with catheterization data using the Gorlin formula, with its inherent limitations, and small discrepancies between the methods are present. To evaluate these differences further, 15 patients with severe aortic stenosis (mean transvalvular gradient 70, range 40-130 mmHg) had aortic valve area estimations by Doppler echocardiography using two variations of the continuity equation. The intact valves removed at valve replacement surgery were then mounted in a pulsatile model and the anatomical area was measured (mean 0.67 +/- 0.17 cm-2) from video recordings during flow at 5.4 l min-1. Aortic valve area calculated using the integrals of the velocity-time curves measured at the left ventricular outflow tract and aortic jet (mean 0.65 +/- 0.17 cm2) correlated best with the anatomical area (r = 0.87, P less than 0.001). The area derived by using the ratio of maximum velocities from the left ventricular outflow tract and aortic jet (mean 0.69 +/- 0.18 cm2) also correlated well with the anatomical area (r = 0.79, P less than 0.001). The index between the left ventricular outflow tract and aortic jet maximum velocities was less than or equal to 0.25 in all. In patients with severe aortic stenosis the aortic valve area can be reliably estimated using Doppler echocardiography.     

Evaluation of aortic insufficiency by Doppler color flow mapping

The color Doppler echocardiographic studies and aortic angiograms of all patients who had these procedures performed within 2 weeks of each other between October 1984 and August 1985 were reviewed to determine whether any parameters of the regurgitant jet visualized by color Doppler study predicted the severity of aortic insufficiency as assessed by angiographic grading. Patients with an aortic valve prosthesis were excluded. Twenty-nine patients had aortic insufficiency and had adequate color Doppler studies for analysis. The mean time between color Doppler examination and angiography was 2.3 days (range 0 to 12). The maximal length and area of the regurgitant jet were poorly predictive of the angiographic grade of aortic insufficiency. The short-axis area of the regurgitant jet from the parasternal short-axis view at the level of the high left ventricular outflow tract relative to the short-axis area of the left ventricular outflow tract at the same location best predicted angiographic grade, correctly classifying 23 of 24 patients. However, the jet could be seen from this view in only 24 of the 29 patients. The height of the regurgitant jet relative to left ventricular outflow tract height measured from the parasternal long-axis view just beneath the aortic valve correctly classified 23 of the 29 patients. Mitral stenosis or valve prosthesis, which was present in 10 patients, did not interfere with the diagnosis or quantitation of aortic insufficiency by these methods.(ABSTRACT TRUNCATED AT 250 WORDS)     

Aortic regurgitation associated with hypertrophic cardiomyopathy: a colour Doppler echocardiographic study.

The frequency, severity, and cause of aortic regurgitation were assessed by colour Doppler and cross sectional echocardiography in 87 patients (mean SD) age 57 (12) years) with hypertrophic cardiomyopathy, and 48 age matched controls (57 (8) years). Aortic regurgitant murmurs were recorded in only three of 87 patients and in none of the controls. Colour Doppler echocardiography showed an aortic regurgitant signal in 20 (23%) of the patients and three (6%) of the 48 controls. The colour Doppler signals typical of aortic regurgitation were limited to the left ventricular outflow tract. There were no significant differences between patients with hypertrophic cardiomyopathy with and without aortic regurgitation in terms of age (59 years v 56 years), blood pressure (140/84 mm Hg v 136/80 mm Hg), aortic diameter (34 mm v 33 mm), or frequency of calcification of the aortic valve (15% v 10%) and of systolic anterior motion of the mitral valve with mitral-septal contact (25% v 16%). On cross sectional echocardiograms, the degree of septal protrusion into the left ventricular outflow tract during systole was significantly more prominent (15 v 10 mm), and the portion of the basal septum that protruded most deeply into the left ventricular outflow tract was significantly closer to the aortic annulus in patients with aortic regurgitation than in those without it (11 v 14 mm). Mild aortic regurgitation was found in almost a quarter of patients with hypertrophic cardiomyopathy. The regurgitation was related to the morphological abnormality of the left ventricular outflow tract.     

Aortic regurgitation associated with hypertrophic cardiomyopathy: a colour Doppler echocardiographic study

The frequency, severity, and cause of aortic regurgitation were assessed by colour Doppler and cross sectional echocardiography in 87 patients (mean SD) age 57 (12) years) with hypertrophic cardiomyopathy, and 48 age matched controls (57 (8) years). Aortic regurgitant murmurs were recorded in only three of 87 patients and in none of the controls. Colour Doppler echocardiography showed an aortic regurgitant signal in 20 (23%) of the patients and three (6%) of the 48 controls. The colour Doppler signals typical of aortic regurgitation were limited to the left ventricular outflow tract. There were no significant differences between patients with hypertrophic cardiomyopathy with and without aortic regurgitation in terms of age (59 years v 56 years), blood pressure (140/84 mm Hg v 136/80 mm Hg), aortic diameter (34 mm v 33 mm), or frequency of calcification of the aortic valve (15% v 10%) and of systolic anterior motion of the mitral valve with mitral-septal contact (25% v 16%). On cross sectional echocardiograms, the degree of septal protrusion into the left ventricular outflow tract during systole was significantly more prominent (15 v 10 mm), and the portion of the basal septum that protruded most deeply into the left ventricular outflow tract was significantly closer to the aortic annulus in patients with aortic regurgitation than in those without it (11 v 14 mm). Mild aortic regurgitation was found in almost a quarter of patients with hypertrophic cardiomyopathy. The regurgitation was related to the morphological abnormality of the left ventricular outflow tract.     

Evaluation of aortic valve insufficiency using color Doppler echocardiography

Colour flow mapping Doppler echocardiography is a new, noninvasive method for studying the direction and velocity of blood flow within the cardiac chambers. In order to estimate the sensitivity and specificity of this method in the evaluation of aortic regurgitation, 44 patients were examined consecutively. In 24 patients, aortic valve incompetence was proven by angiography; in 20 patients aortography revealed no regurgitation. Quantification of the severity of aortic insufficiency was performed by grading the amount of colour of the regurgitant flow (grade I-IV) and comparing it with the angiographic data. In 43 out of 44 patients diagnostic images could be obtained with colour flow mapping Doppler echocardiography. With this method aortic insufficiency was detected in all cases (sensitivity 100%). The specificity was 97% (one false positive diagnosis). For quantification of the severity of regurgitation agreement with the angiographic findings was obtained in 18 out of 24 cases. In the remaining 6 patients the difference was one grade. Conclusion: Colour flow mapping Doppler echocardiography is an important advance in the noninvasive preoperative diagnostics of aortic incompetence.     

Clinical value of the detection of diastolic mitral regurgitation by pulsed Doppler

The reliability of pulsed Doppler echocardiography for the detection of mitral diastolic regurgitation was evaluated in 21 patients with severe aortic insufficiency and/or cardiomyopathy. Among these patients, 17 had sinus rhythm with a normal PR interval, while 4 had atrial fibrillation with short or normally lasting diastoles. Detection was negative in 10 cases (group A) and positive in the remaining 11 cases (group B). In all patients the data supplied by Doppler echocardiography were confirmed by angiography (100% sensitivity and specificity). A comparative study of right heart and left heart pressures in the two groups showed that group B patients had a special pressure profile, the most significant feature of which was an increase in pulmonary arterial and capillary pressures (p less than 0.01 and p less than 0.001 respectively). The diagnostic reliability of mitral valve diastolic regurgitation as to the presence of an abnormal mean pulmonary pressure was: sensitivity 80%, specificity 73%. Right heart pressures were either normal or very slightly elevated in group A patients. It is concluded that the presence of mitral diastolic regurgitation in patients with the pathology described indicates an unfavourable prognosis. This should be taken into account and lead to a systematic of mitral flow in these patients.     

Experimental validation of Doppler echocardiographic measurement of volume flow through the stenotic aortic valve

In aortic stenosis, evaluation of aortic valve area by the continuity equation assumes that the volume of flow through the stenotic valve can be measured accurately in the left ventricular outflow tract. To test the accuracy of Doppler volume-flow measurement proximal to a stenotic valve, we developed an open-chest canine model in which the native leaflets were sutured together to create variable degrees of acute aortic stenosis. Left ventricular and aortic pressures were measured with micromanometer-tipped catheters. Volume flow was controlled and varied by directing systemic venous return through a calibrated roller pump and back to the right atrium. Because transaortic volume flow will not equal roller pump output when there is coexisting aortic insufficiency (present in 67% of studies), transaortic flow was measured by electromagnetic flowmeter with the flow probe placed around the proximal descending thoracic aorta, just beyond the ligated arch vessels. In 12 adult, mongrel dogs (mean weight, 25 kg), the mean transaortic pressure gradient ranged from 2 to 74 mm Hg, and transaortic volume flow ranged from 0.9 to 3.2 l/min. In four dogs, electromagnetic flow that was measured distal to the valve was accurate compared with volume flow determined by timed collection of total aortic flow into a graduated cylinder (n = 24, r = 0.97, electromagnetic flow = 0.87 Direct +0.13 l/min). In eight subsequent dogs, electromagnetic flow was compared with transaortic cardiac output measured by Doppler echocardiography in the left ventricular outflow tract as circular cross-sectional area [pi(D/2)2] x left ventricular outflow tract velocity-time integral x heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reproducibility of Doppler echocardiographic quantification of aortic and mitral valve stenoses: comparison between two echocardiography centers

Doppler echocardiography has been widely used as a noninvasive method to quantify valvular heart diseases. This study assessed the variability between 2 echocardiography centers concerning 2-dimensional and Doppler echocardiographic results in the quantification of mitral and aortic valve stenoses. Forty-two patients were studied by 2 different echocardiography centers in a blinded, independent fashion. In patients with aortic and mitral valve stenosis, mean and maximal flow velocities were measured. The aortic valve orifice area was calculated according to the continuity equation. Mitral valve orifice area was determined by direct planimetry and by pressure half-time. In patients with an aortic valve stenosis, a close relation between the 2 centers was found for the maximal and mean flow velocities (coefficient of correlation, r = 0.72 to 0.92; coefficient of variation, 3.7 to 7.7%). A close correlation and a small observer variability was found for the flow velocity ratio determined by flow velocities measured in the left ventricular outflow tract and over the stenotic valve (r = 0.88; coefficient of variation, 0.01 +/- 0.009). In contrast, there was a poor correlation between the diameter of the left ventricular outflow tract and the aortic orifice area (r = 0.36 and 0.59, respectively). In patients with a mitral valve stenosis, mean and maximal velocities were closely correlated (r = 0.85 and 0.77, respectively). Velocities were not found to be significantly different between the 2 centers. Variability between the 2 centers for the mitral valve orifice area was 9.8% (2-dimensional echocardiography) and 5.7% (pressure half-time).(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Left ventricular systolic and diastolic flow abnormalities determined by Doppler echocardiography in obstructive hypertrophic cardiomyopathy

To analyze the relation of systolic anterior motion (SAM) of the mitral valve, peak left ventricular (LV) outflow tract velocity, aortic flow and mitral flow, 17 patients with obstructive hypertrophic cardiomyopathy (HC) (8 men, 9 women), aged 19 to 88 years (mean 45), were studied using M-mode and 2-dimensional echocardiography and pulsed and continuous-wave Doppler echocardiography and results were compared with those from 18 age-matched normal subjects. SAM was present in all patients with HC and absent in normal subjects. Time to peak outflow velocity as a percentage of LV ejection time was 63% in patients with HC and 29% in normal subjects (p less than 0.001). In 13 patients, time from the R-wave peak to the closest approximation of the mitral valve to the ventricular septum or initial contact during SAM was determined and was 242 +/- 66 ms and time from the R-wave peak to the peak LV outflow tract velocity was 242 +/- 73 ms (r = 0.90). In 11 patients time from the R-wave peak to cessation of flow in the ascending aorta was measured and was 286 +/- 80 ms; time from the R-wave peak to the peak LV outflow tract velocity was 246 +/- 75 ms. The ratio of early to late diastolic filling velocities of the left ventricle was 1.47 +/- 0.40 in the normal subjects and 1.26 +/- 0.84 in patients with HC (difference not significant). The early to late ratio of the 12 patients without mitral regurgitation was 0.99 +/- 0.52 (p less than 0.01 vs normal subjects).(ABSTRACT TRUNCATED AT 250 WORDS)