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.     

Quantitative assessment of the hemodynamic consequences of aortic regurgitation by means of continuous wave Doppler recordings

The purpose of this study was to evaluate the ability of continuous wave Doppler ultrasound recordings to reflect the magnitude and hemodynamic effects of aortic regurgitation. Forty-five patients with angiographically proved aortic regurgitation had Doppler studies performed within 24 hours of cardiac catheterization. High quality spectral recordings of the regurgitant jet were obtained in 31 patients, whereas 14 patients exhibited dropout of high velocity signals precluding measurement of maximal velocities. The slope of the peak to end-diastolic velocity decrease measured by Doppler examination was compared with the decay in the aortic to left ventricular diastolic pressure gradient by catheterization and was found to correlate well (r = 0.86). The Doppler velocity decay slope was generally higher in patients with angiographically severe rather than mild or moderate aortic regurgitation, but considerable overlap was present among groups. However, a diastolic velocity decay slope of greater than 3 m/s2 was seen only in those patients with advanced (3 or 4+) aortic regurgitation. Left ventricular end-diastolic pressure was estimated from the Doppler recordings by subtracting the end-diastolic pressure gradient obtained by the modified Bernoulli equation from the cuff diastolic blood pressure. A correlation was observed (r = 0.84) between Doppler and catheterization left ventricular end-diastolic pressure in the 31 patients with high quality spectral data, although the SEE was substantial (5.5 mm Hg). These data demonstrate that continuous wave Doppler recordings of the regurgitant jet can be useful in assessing the angiographic severity and hemodynamics of aortic regurgitation.     

Doppler assessment of aortic regurgitation. Correlation with hemodynamics and angiography

The Doppler method by permitting assessment of transvalvular blood flow velocity has provided a direct means to interrogate aortic regurgitant flow. Pulsed Doppler permits detection of disturbed diastolic flow by sampling proximal to the aortic valve in the outflow tract and is highly sensitive for diagnosis of aortic regurgitation (AR). For semi-quantitative assessment of the severity, left ventricular (LV) mapping can be performed and a ratio of the area of retrograde diastolic to antegrade systolic flow in the descending aorta can be used. According to the continuity principle, it should be possible to estimate regurgitant fraction by examination of forward flows from two different sites, one representative of forward output and one of total left ventricular output, but this method has not yet been sufficiently validated. Continuous wave (CW) Doppler is nearly as sensitive for detection of aortic regurgitation as pulsed wave (PW) Doppler. Signal strength of regurgitant jet provides an indirect clue to its severity: generally a strong signal indicates moderate to severe degree, a weak signal is associated with mild degrees of regurgitation. The spectral outline of regurgitant jet velocity is determined by instantaneous pressure difference between aortic root and the left ventricle during diastole and an indirect clue to severity of aortic regurgitation is provided by the slope of the curve. A steeper slope or shorter velocity half-time is associated with more severe degrees of regurgitation and vice versa. However, there is considerable scatter in this correlation for any given grade of severity of aortic regurgitation, providing a limited predictive value.(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantification of aortic regurgitation utilizing continuous wave Doppler ultrasound

Aortic regurgitation and mitral stenosis are hemodynamically similar, insofar as both result in passive ventricular filling across a narrow orifice driven by a declining pressure gradient. Because mitral stenosis is successfully characterized by Doppler ultrasound determination of the velocity half-time, or time constant, aortic regurgitation might be quantified in an analogous fashion. Eighty-six patients with diverse causes of aortic regurgitation underwent continuous wave Doppler examination before cardiac catheterization or urgent aortic valve replacement. The Doppler velocity half-time was defined as the time required for the diastolic aortic regurgitation velocity profile to decay by 29%, whereas catheterization pressure half-time was calculated as the time required for transvalvular pressure to decay by 50%. Doppler velocity and catheterization pressure half-times were linearly related (r = 0.91). Doppler velocity half-times were inversely related to regurgitant fraction (r = -0.88). Angiographic severity (1+ = mild to 4+ = severe) was also inversely related to pressure and velocity half-time; a Doppler half-time threshold of 400 ms separated mild (1+, 2+) from significant (3+, 4+) aortic regurgitation with high specificity (0.92) and predictive value (0.90). The Doppler velocity half-time was independent of pulse pressure, mean arterial pressure, ejection fraction and left ventricular end-diastolic pressure. Estimation of transvalvular aortic pressure half-time utilizing continuous wave Doppler ultrasound is a reliable and accurate method for the noninvasive evaluation 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)     

Quantitative assessment of aortic regurgitation by combined two-dimensional, continuous-wave and colour flow Doppler measurements.

The width of the regurgitant jet at the aortic valve plane, i.e. the core flow diameter, the ratio of the jet width to the left ventricular outflow diameter, the regurgitant volume and regurgitant fraction were determined using two-dimensional, continuous wave and colour flow Doppler echocardiography. The relationship between the non-invasive measurements and semiquantitative angiographic grading of the regurgitant flow (1 + to 4+) was examined in a primary group of 20 patients with chronic aortic regurgitation. Cut-off points for the non-invasive measurements were selected so as to separate patients with mild or moderate regurgitation (1+ or 2+) from patients with moderately severe or severe regurgitation (3+ or 4+). These cut-off points were prospectively applied in a new group of 35 patients with aortic regurgitation to predict the angiographic grading. Jet width correctly predicted the angiographic grading in 86% of cases, the ratio of the jet width to the outflow diameter in 83% of cases, the regurgitant volume in 86% of cases and the regurgitant fraction in 91% of cases. We conclude that the severity of aortic regurgitation as determined by angiographic grading can be estimated with reasonable accuracy by non-invasive techniques based on colour flow imaging.     

Pulsed and continuous wave Doppler echocardiographic assessment of valvular regurgitation in normal subjects

To assess the prevalence and flow characteristics of valvular regurgitation detected by Doppler echocardiography in normal subjects, pulsed and continuous wave Doppler studies were performed in 100 adult volunteers without evidence of heart disease. Evidence of valvular regurgitation was present in 73% of subjects. There were 46 subjects with regurgitation of one valve, 24 with regurgitation of two valves and 3 with regurgitation of three valves. Right-sided regurgitation was significantly more common than was left-sided regurgitation (81 versus 22 valves, p less than 0.01). Regurgitant flow was never detected farther than 1 cm from the valve by pulsed Doppler study. Tricuspid regurgitation was detected in 50 subjects and was characterized by a holosystolic velocity signal; a complete spectral envelope was recorded in 32 subjects. The peak velocity of the regurgitant jet for this group was 1.7 to 2.3 m/s (mean 2.0 +/- 0.2). Thirty-one subjects were found to have pulmonary regurgitation with a peak velocity of 1.2 to 1.9 m/s (mean 1.5 +/- 0.2); no subject demonstrated regurgitant flow in early diastole. There were 21 subjects with mitral regurgitation; continuous wave Doppler signals were always of low intensity with a poorly defined spectral envelope and an absence of high velocities. Peak velocities ranged from 1.1 to 4.4 m/s (mean 2.3 +/- 0.9) and in 19 subjects were less than 3.5 m/s. The mean age of subjects with mitral regurgitation was significantly higher than that of subjects without mitral regurgitation (p = 0.01). Aortic regurgitation was detected in only one subject. This study provides further evidence that valvular regurgitation is frequently detected by Doppler echocardiography in normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Calculation of aortic regurgitation orifice area by Doppler echocardiography: an application of the continuity equation.

The evaluation of aortic regurgitation by current echocardiographic techniques has been qualitative and load-dependent. The area of the regurgitant orifice, which is theoretically independent of haemodynamic conditions, has not been determined non-invasively. In 20 patients with various degrees of aortic regurgitation, this area was determined by use of the continuity equation applied during diastole. The velocity-time integrals were determined at the supravalvar (VTIs) and regurgitant orifice (VTIj) levels by pulsed and continuous wave Doppler respectively. The cross sectional area at the supravalvar level (As) was also measured by cross sectional echocardiography. The regurgitant orifice is given by: (As x VTIs)/VTIj. Other non-invasive measurements of the aortic regurgitation severity were also recorded: (a) an overall echo score (1-5+) given blindly by two echocardiographers, (b) the maximal proximal jet width by colour Doppler, (c) left ventricular end systolic and end diastolic volumes and left ventricular mass. The regurgitant area ranged from 0.25 to 1.7 cm2 and this area accorded with the overall echo score and the maximal proximal jet width measured by colour Doppler. The aortic regurgitation orifice area can be calculated non-invasively and it may be a quantitative measure of the severity of aortic regurgitation.     

Pitfalls in the diagnosis of periprosthetic valvular regurgitation by pulsed Doppler echocardiography

Pulsed Doppler echocardiographic diagnosis of periprosthetic valvular insufficiency may be difficult. This report details the pulsed Doppler echocardiographic findings in two patients who developed severe periprosthetic mitral regurgitation after porcine mitral valve replacement. In both patients, mitral regurgitation was difficult to diagnose and left atrial turbulence, when detected, appeared localized, suggesting only mild mitral regurgitation. However, the combination of abnormally high peak transmitral diastolic flow velocity, with a normal pressure half-time, and increased flow velocity in the tricuspid regurgitant jet compatible with severe pulmonary hypertension, in the absence of other apparent left heart disease, suggested the correct diagnosis of severe mitral regurgitation in both cases. Techniques for optimal pulsed Doppler assessment of the mitral anulus region are emphasized, as are the theoretic advantages of continuous wave and color-coded pulsed Doppler echocardiography for detection of periprosthetic regurgitation.     

Effective aortic regurgitant orifice area: description of a method based on the conservation of mass

The natural history of aortic regurgitation is incompletely understood in part because of the lack of a simple method to estimate the defect size. A method of determining the effective regurgitant orifice area that combines Doppler catheter and Doppler echocardiographic techniques and is based on the principle of conservation of mass (the continuity equation) is described. To validate the application of the Doppler catheter system for measuring regurgitant supravalvular diastolic flow, an in vitro model of retrograde aortic flow was used. These studies indicated that measurements of supravalvular retrograde velocity with the Doppler catheter accurately reflect retrograde diastolic velocity when the aorta is less than 4.8 cm in diameter. Twenty-three patients undergoing cardiac catheterization were studied; 20 of these patients had aortic regurgitation. Retrograde supravalvular diastolic velocity was determined from a Doppler catheter positioned above the aortic valve. The effective regurgitant orifice area was calculated with use of the Doppler catheter-derived regurgitant volume and mean transvalvular diastolic velocity as determined by either catheterization or continuous wave Doppler echocardiography. The catheterization-derived regurgitant orifice area increased with the angiographic grade of as follows: 1+ (0.04 to 0.10 cm2), 2+ (0.15 to 0.49 cm2), 3+ (0.29 to 1.11 cm2) and 4+ (1.24 to 1.33 cm2). By combining Doppler catheter, echocardiographic and cardiac catheterization techniques, the effective aortic regurgitant orifice area may be estimated; this hydrodynamic area correlates with grading by supravalvular aortography. Calculation of this area provides a quantitative alternative to aortography for estimating the severity of aortic regurgitation but should be used with caution in patients with a markedly dilated aorta.     

Strategy for optimal aortic regurgitation quantification by Doppler echocardiography: agreement among different methods

BACKGROUND: Although different Doppler methods have been validated for aortic regurgitation quantification, the benefit of combining information from different methods has not been defined. METHODS: Our study included 2 phases. In the initial phase (60 patients), Doppler parameters (jet width, short-axis jet area, apical jet area, regurgitant fraction from pulmonary and mitral flow, and deceleration slope) were correlated with angiography; range values for each severity grade were defined and intraobserver and interobserver and intermachine variability were studied. In the validation phase (158 patients), defined value ranges were prospectively tested and a strategy based on considering as the definitive severity grade that in which the two best methods agreed was tested. RESULTS: Jet width had the best correlation with angiography (r = 0.91), and its ratio with the left ventricular outflow diameter did not improve the correlation (r = 0.85) and decreased reproducibility. Apical jet area and regurgitant fraction from pulmonary flow permitted acceptable quantification (r = 0.87 and 0.86, respectively) but with worse reproducibility. The other methods were not assessable in 20% to 30% of studies. Concordance with angiography decreased in jet width when the jet was eccentric (90% vs 77%, P <.01), in apical jet area when mitral valve disease was present (84% vs 65%, P <.02), and in short-axis jet area and regurgitant fraction from pulmonary flow with concomitant aortic stenosis (77% vs 44%, P <.002 and 77% vs 53%, P <.02, respectively). Agreement with angiography was very high (94 [95%] of 99) when severity grade coincided in both jet width and apical jet area. In 59 cases without concordance, regurgitant fraction from pulmonary flow was used as a third method. Overall, this strategy permitted concordance with angiography in 146 patients (92%). CONCLUSIONS: Jet width is the best predictor in aortic regurgitation quantification by Doppler echocardiography. However, better results were obtained when a strategy based on concordance between jet width and another Doppler method was established, particularly when the jet was eccentric.     

Relation between Doppler color flow variables and invasively determined jet variables in patients with aortic regurgitation.

OBJECTIVES. The purpose of this study was to test the hypothesis that invasively derived jet variables including regurgitant orifice area and momentum determine the characteristics of Doppler color flow jets in patients with aortic regurgitation. BACKGROUND. In vitro studies have demonstrated that the velocity distribution of a regurgitant jet is best characterized by the momentum of the jet, which incorporates orifice area and velocity of flow through the orifice. METHODS. Peak jet momentum, peak flow rate and regurgitant orifice area were determined with intraaortic Doppler catheter and cardiac catheterization techniques in 22 patients with chronic aortic regurgitation. These invasively derived variables were compared with apical and parasternal long-axis Doppler color echocardiographic variables obtained in the catheterization laboratory. RESULTS. Jet momentum increased significantly with the angiographic grade of regurgitation. The apical color jet area of aortic regurgitation increased linearly with jet momentum and regurgitant orifice area in vivo, but the correlations were only moderately good (r = 0.63 and 0.65, respectively). Color jet length also increased linearly with jet momentum and with regurgitant orifice area. There was only a trend for Doppler color jet width to increase with all invasively derived jet variables. CONCLUSIONS. Whereas jet area by Doppler color flow imaging is directly related to both orifice area and jet momentum in vivo, Doppler color variables measured in planes normal to the orifice do not correlate well enough with either jet momentum or regurgitant orifice area to predict jet flow variables in patients with aortic regurgitation. It is likely that the important influence of adjacent boundaries will limit the use of the velocity distribution of aortic regurgitant jets for determining the severity of disease.     

Prevalence of pulmonary valve insufficiency in healthy children: a Doppler color study

One hundred patients, institutionalized for mental retardation, aged between 3 and 14 years (mean age 12.2 +/- 3) and free from cardiovascular and pulmonary diseases, were studied using Doppler technique (pulsed wave-continuous wave and color-coded Doppler), to evaluate the prevalence of pulmonary regurgitation. The authors, utilizing a triple method (diastolic turbulence above pulmonary valve detected by pulsed wave Doppler or diastolic flow detected by continuous wave Doppler, presence of regurgitant pulmonary color-jet, from short axis view, toward the right ventricular outflow tract, and presence of the same feature in the color m-multigate) to detect the presence or absence of pulmonary regurgitation found 73% positivity. There were no differences between the two sexes and the size of the pulmonary artery was in the normal range. The characteristics of regurgitation were: No holodiastolic. The regurgitant max velocity jet was not greater than 1.50 m/s. Beat to beat variability. Max length of color-jet was not more than 2 cm. Rapidly decreasing Doppler profile. We can conclude that pulmonary regurgitation is very frequent in children and is not significant if it has the above-named characteristics. This latter fact is further confirmed by other authors.     

Assessment of severity of aortic regurgitation by M-mode colour Doppler flow imaging

To assess the value of measuring the aortic regurgitant jet diameter at its origin by M-mode colour Doppler imaging, 82 patients with aortic regurgitation underwent, within 72 h of each other, colour Doppler examination and angiography. After excluding one patient without colour Doppler aortic regurgitation and five with a highly eccentric regurgitant jet, we found a close relationship between the jet diameter at its origin measured by M-mode colour Doppler and the angiographic grade of aortic regurgitation (r = 0.88). A jet diameter greater than or equal to 12 mm identified severe aortic regurgitation (grade III or IV) with a sensitivity of 86.4% and a specificity of 94.4%. In 38 patients, the jet diameter correlated well with the regurgitant fraction measured by a combined haemodynamic-angiographic method (r = 0.88). A jet diameter greater than or equal to 12 mm identified a regurgitant fraction greater than or equal to 40% with a sensitivity of 88.2% and a specificity of 95.2%. This study indicates that the size of the regurgitant jet diameter at its origin measured by M-mode colour Doppler provides a simple and useful measure of the severity of aortic regurgitation. It may allow differentiation between mild or moderate and severe aortic regurgitation and evaluation of regurgitant fraction.     

Noninvasive evaluation of aortic regurgitation by continuous-wave Doppler echocardiography

Continuous-wave Doppler echocardiography was used to examine the aortic regurgitant flow velocity pattern in 32 patients with aortic regurgitation (AR) and 10 patients without AR. The aortic regurgitant flow velocity patterns, characterized by a rapid rise in flow velocity immediately after closure of the aortic valve, high peak flow velocity, and a gradual deceleration until the next aortic valve opening, were successfully obtained in 30 of the 32 patients with AR (sensitivity 94%, specificity 100%). The velocity decline was greater in patients with severe AR; thus, the slope of the velocity decline (deceleration) and the time to decline to half the peak velocity (half-time index) were measured from the flow velocity pattern. The deceleration became greater and the half-time index shortened in accordance with angiographic grading of AR (p less than .01). The deceleration and the half-time index also correlated well with the aortic regurgitant fraction (r = .79, p less than .01; r = -.89, p less than .01). Because the half-time index could be measured easily and independently of Doppler incident angle, it seemed a simple and accurate index of assessing the severity of AR. Thus continuous-wave Doppler echocardiography permitted the noninvasive evaluation of AR.     

Independent pulsed Doppler mapping techniques. Limitations in the prediction of the angiographic severity of mitral regurgitation

Pulsed Doppler mapping of the flow disturbance of mitral insufficiency is commonly employed to estimate the severity of regurgitation. We re-examined the customary pulsed Doppler criterion of relative depth of jet penetration (MR ratio) in 50 patients undergoing left ventriculography and found a modest correlation (r = 0.70) between Doppler and angiographic estimates of regurgitant grade. The MR ratio did not provide statistically significant separation between adjacent angiographic grades 1+ to 3+ (scale 0 to 4+). However, when the data were re-analyzed for the subset of 36 patients with pure mitral regurgitation the correlation between Doppler and angiographic estimates of regurgitant grade improved dramatically (r = 0.88) and MR ratio provided statistically significant separation between all angiographic grades with the sole exception of the distinction between 1+ and 2+ regurgitation. The presence of restriction of the regurgitant orifice in the remaining 14 patients with relative mitral inflow obstruction may result in a nozzle effect on the regurgitant jet which alters the relationship between depth of jet penetration and severity of regurgitation. In this latter group of patients independent pulsed Doppler mapping techniques may provide inaccurate estimates of the angiographic severity of mitral regurgitation.     

Silent severe tricuspid regurgitation: a study by Doppler echocardiography

Sixty-eight patients with severe tricuspid regurgitation proven by right ventriculography were examined using pulsed and continuous wave Doppler echocardiography and color Doppler flow imaging. Among the 68 patients, there was no tricuspid regurgitant murmur in 16 (24%) in whom laminar regurgitant flow signals were demonstrated by pulsed Doppler echocardiography. The area in which laminar flow was detected ranged from 8 to 46 mm2 (mean 19.5 +/- 9.8 mm2). The peak velocities in patients without regurgitant murmurs as measured by continuous wave Doppler echocardiography ranged from 1.1 to 1.9 m/sec (mean: 1.61 +/- 0.21 m/sec). Laminar regurgitant flow signals were obtained in six; and turbulent regurgitant flow signals in 46 of 52 patients with tricuspid regurgitant murmurs, and their peak velocities ranged from 1.7 to 5.1 m/sec (2.80 +/- 0.78 m/sec). The peak velocities of the regurgitant flow signals in patients without tricuspid regurgitant murmurs were significantly lower than those in patients with regurgitant murmurs (p less than 0.01). In six patients with laminar regurgitant flow signals and regurgitant murmurs, the areas of laminar flow signals ranged from 3 to 12 mm2 (mean 7.0 +/- 3.5 mm2) and were smaller than those of patients without regurgitant murmurs (p less than 0.001). A characteristic candle flame pattern of regurgitant flow signals was observed in all patients without murmurs. Thus, the absence of a tricuspid regurgitant murmur results from laminar regurgitant flow signals of low velocity and this is characterized by a candle flame pattern using color Doppler flow imaging.     

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.     

The effect of heart rate on color M-mode Doppler flow propagation velocity and continuous-wave Doppler parameters in aortic insufficiency

BACKGROUND AND AIM OF THE STUDY: The results of previous studies have suggested that an increase in heart rate (HR) may have a beneficial effect on the hemodynamic condition of patients with aortic regurgitation (AR), and reduce AR severity. An increase in HR was shown to cause a significant increase in regurgitant slope and to significantly shorten the pressure half-time (PHT), both of which are considered to be signs of worsening regurgitation. Color M-mode Doppler flow propagation velocity (FPV) was used to assess AR severity, but no data were available regarding the effects of HR on FPV measurement of AR. The study aim was to evaluate the effect of HR on FPV, and to compare FPV and continuous-wave (CW) Doppler parameter (PHT and slope) variations resulting from an increase in HR. METHODS: Sixty-eight patients (28 males, 40 females; mean age 52 +/- 15 years) with AR of various severity were included. Color M-mode Doppler was used in FPV, while CW Doppler was used in PHT and slope measurements. Atropine sulfate was titrated in all patients to achieve at least a 20% increase in HR. The FPV, PHT, slope and regurgitant fraction (RF) of AR were measured before and after the increase in HR. RESULTS: An increase in HR (77.8 +/- 8.9 versus 103 +/- 9.9 bpm; p < 0.001) caused a decrease in color M-mode Doppler FPV (51 +/- 21 versus 44 +/- 19 cm/s), in the PHT of the regurgitant velocity curve (468 +/- 154 versus 411 +/- 128 ms), and in the RF of the AR (30.2 +/- 16.3 versus 26.1 +/- 14%). The slope of the regurgitant velocity was increased (291 +/- 136 versus 358 +/- 122 cm/s2). All of these variations were statistically significant. CONCLUSION: An increase in HR caused a decrease in the FPV and RF of the aortic regurgitation, and both changes were signs of improved regurgitation. FPV appears to be a more valuable parameter than CW Doppler parameters in determining improvements in AR resulting from an increase in HR.