Pulsed Doppler echocardiographic evaluation of valvular regurgitation in patients with mitral valve prolapse: comparison with normal subjects

Pulsed Doppler echocardiography was used to determine prospectively the prevalence of mitral, aortic, tricuspid and pulmonary regurgitation in 80 consecutive patients with mitral valve prolapse and 85 normal subjects with similar age and sex distribution. Mitral valve prolapse was defined by posterior systolic displacement of the mitral valve on M-mode echocardiography of 3 mm or more (40 patients), the presence of one or more mid- or late systolic clicks (61 patients), or both. Mitral regurgitation, detected by pulsed Doppler techniques in 53 patients with prolapse, was holosystolic in 24, early to mid-systolic in 6, late systolic in 15 and both holosystolic and late systolic behind different portions of the valve in 8. Definitive M-mode findings were present in only 27 of the 53 patients, and only 21 had mitral regurgitation audible on physical examination. Tricuspid regurgitation was evident by pulsed Doppler echocardiography in 15 patients (holosystolic in 9, early to mid-systolic in 1, late systolic in 4 and both holosystolic and late systolic in 1); 12 of these 15 patients, including all with an isolated late systolic pattern, had an echocardiographic pattern of tricuspid prolapse, but none had audible tricuspid regurgitation. A Doppler pattern compatible with aortic regurgitation was recorded in seven patients, all without echocardiographic aortic valve prolapse and only two with audible aortic insufficiency. A Doppler shift in the right ventricular outflow tract in diastole, suggestive of pulmonary regurgitation, was recorded in 16 of the 78 patients with an adequate Doppler examination: only 1 of the 16 had audible pulmonary insufficiency. Of the 85 normal subjects without audible regurgitation, pulsed Doppler examination detected mitral regurgitation in 3 subjects (holosystolic in 1 and early to mid-systolic in 2), aortic regurgitation in none, tricuspid regurgitation in 9 (holosystolic alone in 8 and both holosystolic and late systolic in 1) and right ventricular outflow tract turbulence compatible with pulmonary insufficiency in 15. The prevalence of valvular regurgitation, detected by pulsed Doppler echocardiography, is high in patients with mitral valve prolapse. Regurgitation may involve any of the four cardiac valves and is clinically silent in the majority of patients. The prevalence rates of mitral and aortic regurgitation are significantly higher in patients with mitral prolapse than in normal subjects, suggesting that alterations in underlying valve structure in the prolapse syndrome may indeed be responsible for this regurgitation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Color Doppler evaluation of valvular regurgitation in normal subjects

430 apparently healthy subjects were studied with color Doppler flow imaging system. There were 216 females and 214 males, their age ranged from 4-80 years (mean 41.2 years). They were divided into 6 groups by every ten years of age, with group I having age below 19 and group VI age above 70. None of the subjects had previous diagnosis of cardiovascular diseases. Mitral regurgitation was detected in 30.9-52.8% in all the groups except group I, in which it was found in 20.0% only. The prevalence rate of tricuspid regurgitation was 9.8-36% in the six groups. Pulmonary regurgitation signals were detected in 43.8-4.8% in these groups with a tendency of lower incidence in the elderly. Aortic regurgitation were detected only in the three elder groups with an incidence of 5.5% in group 4 and 13.6% in group 6. The reason for that may be the degeneration of aortic valve with aging. Our study showed that in a large proportion of normal persons color Doppler echocardiography allows recording of regurgitation signals behind cardiac valves except for aortic valve. The regurgitation volume was small and there was no significant hemodynamic effect. The size and diameter of the heart chambers were normal when compared with other studies.     

Color Doppler evaluation of valvular regurgitation in normal subjects

To determine prospectively the prevalence of mitral, aortic, tricuspid, and pulmonary regurgitation in normal persons, 211 consecutive, apparently healthy volunteers were examined with a color Doppler flow imaging system. The subjects were divided into five age groups (group 1, 6-9 years old; group 2, 10-19 years old, group 3, 20-29 years old, group 4, 30-39 years old, and group 5, 40-49 years old). The prevalence rate of mitral regurgitation in the normal subjects was 38-45% in each group. The mitral regurgitant jets came from the posteromedial commissure in all but two subjects. No aortic regurgitant flow signals were detected in the normal subjects. Tricuspid regurgitation was detected in 15-77% in each group, and pulmonary regurgitation was detected in 28-88%. Regarding the tricuspid and pulmonic valves, the prevalence rate of regurgitation is age dependent (p less than 0.01) and tends toward the lower rate in groups over the age of 30 years. The tricuspid and pulmonary regurgitant jets came from the center of the coaptation of each valve. The area of the regurgitant jet signals in normal persons was significantly smaller (p less than 0.001) than that obtained from patients with organic valve disease. Our study shows that in a large proportion of normal persons under the age of 50 years color Doppler echocardiography permits recording of regurgitant signals behind all valves except the aortic. In conclusion, one should be aware of the existence and characteristics of regurgitation in normal persons when evaluating valvular regurgitation by Doppler techniques.     

Pulsed Doppler echocardiographic indices of left ventricular diastolic function in normal subjects.

To establish the normal limits for various pulsed Doppler echocardiographic indices of left ventricular diastolic function, 92 healthy volunteers aged from 5 to 75 years were prospectively studied. The influence of various variables including age, gender, body surface area, fractional shortening, and left ventricular mass on these parameters was also assessed. Mean (2SD) values for 15 direct and 11 derived parameters were analyzed from transmitral inflow velocity waveform. No statistically significant differences were observed between males and females for any of these parameters. On stepwise multivariate linear regression analysis, age was found to be an independent strong determinant (p less than 0.001) of peak velocity of early diastolic filling wave, area of atrial filling period, deceleration slope, normalized peak filling rate, and early filling fraction. There was a significant correlation between heart rate and time to peak early diastolic velocity, total diastolic time period, early diastolic period, atrial filling period, and atrial filling fraction. It was further observed that a significant correlation (p less than 0.001) persisted between both age and heart rate with area of early filling period, one-third filling area, one-half filling area, ratio of early to atrial peak velocity and area, atrial filling fraction, and one-third filling fraction. None of the parameters were found to correlate with fractional shortening or left ventricular mass. Thus an effort was made to establish normal limits for various Doppler-derived parameters in healthy volunteers for future comparison in diseased states.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pulsed Doppler echocardiographic indices for assessing mitral regurgitation.

Pulsed Doppler indices were devised in order to grade the severity of mitral regurgitation on a quantitative basis. Indices were obtained by mapping the regurgitant jet by recording abnormal systolic Doppler signals detected on a "yes/no" basis using a 3 MHz pulsed Doppler velocimeter associated with a cross sectional real time ultrasonic scanner. Combined information from two echographic planes was used to take into account the geometrical three dimensional configuration of the jet. The following dimensions of the jet were measured: (a) the length and the height in the long axis view of the left atrium (long axis regurgitant index (LARI), 0.5 X length X height); (b) the width at the annulus in the short axis view (short axis regurgitant index (SARI); (c) the total regurgitant index (TRI) calculated as the product of LARI multiplied by SARI. Sixteen normal subjects and 94 patients including 46 cases of mitral regurgitation confirmed by angiography (32 of whom proceeded to surgery) were investigated. The diagnostic sensitivity was 91% and the specificity 94%. The jet was detected in 76% of cases. Indices were correlated with independently performed angiographic grading on a three point scale. The best linear correlation was obtained for the TRI; mean values were significantly increased for each grade of severity. Correlations with invasive procedures showed an 87% success rate for the Doppler prediction of the involved regurgitant leaflet(s) and of the anatomical site of the lesion at the annulus. In addition, an abnormal diastolic signal was found in five of the eight patients with ruptured chordae and also a decreased percentage of systolic shortening of the annulus diameter in patients with mitral regurgitation compared with those without.     

Pulsed Doppler echocardiographic analysis of mitral regurgitation after myocardial infarction

In 72 patients with previous myocardial infarction (MI), mitral regurgitation (MR) was assessed by pulsed-wave Doppler echocardiography and compared with physical and 2-dimensional echocardiographic findings. MR was found by Doppler in 29 of 42 patients (62%) with anterior MI, 11 of 30 (37%) with inferior MI (p less than 0.01) and in none of 20 normal control subjects. MR was more frequent in patients who underwent Doppler study 3 months after MI than in those who underwent Doppler at discharge (anterior MI = 83% vs 50%, p less than 0.01; inferior MI = 47% vs 27%, p = not significant). Of 15 patients who underwent Doppler studies both times, 3 (all with anterior MI) had MR only on the second study. Of the patients with Doppler MR, 12 of 27 (44%) with a left ventricular (LV) ejection fraction (EF) greater than 30% and 1 of 13 (8%) with an EF of 30% or less (p less than 0.01) had an MR systolic murmur. Mitral prolapse or eversion and papillary muscle fibrosis were infrequent in MI patients, whether or not Doppler MR was present. The degree of Doppler MR correlated with EF (r = -0.61), LV systolic volume (r = 0.47), and systolic and diastolic mitral anulus circumference (r = 0.52 and 0.51, respectively). Doppler MR was present in 24 of 28 patients (86%) with an EF of 40% or less and in 16 of 44 (36%) with EF more than 40% (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Natural history of valvular regurgitation using side-by-side echocardiographic analysis in anorexigen-treated subjects

In 1997, the US Food and Drug Administration (FDA) reported valvular regurgitation (aortic regurgitation [AR] mild or greater and/or mitral regurgitation [MR] moderate or greater) in 32.8% of patients treated with anorexigens. This study sought to determine the natural history of valvular regurgitation in patients who were included in the FDA's original report. This was a nonrandomized, natural history study of these subjects. Cohort I consisted of 155 of 186 patients (83%) who were reported to the FDA. Cohort II consisted of a similar group of 311 patients who were not included. Initial echocardiograms were obtained for medical indications before the study initiation, and study echocardiograms were standardized and obtained at 3-month intervals. Level III echocardiographers performed blinded, side-by-side comparison of the first and last study echocardiograms at a core laboratory. Cohorts I and II consisted of predominantly female, middle-aged, obese subjects. At enrollment, patients in cohorts I and II had mild or greater AR (17.9%, 13.5%) and moderate or greater MR (3.3%, 4.0%), respectively, which was less than in the FDA's report. At follow-up, there were no statistically significant changes in the degree of valvular regurgitation in either cohort when the first and last study echocardiograms were read side by side. In conclusion, this natural history follow-up study demonstrates that MR and AR in long-term anorexigen-treated patients was less than reported to the FDA, did not progress, and remained echocardiographically stable during the 10-month duration of the study.     

The prevalence of valvular regurgitation in children with structurally normal hearts: a color Doppler echocardiographic study.

To determine the prevalence of valvular regurgitation in children (from birth to 14 years old) with structurally normal hearts, the records of 1360 consecutive patients referred for echocardiographic and Doppler examination were analyzed. A total of 461 (33.9%) patients were found to have structurally normal hearts. Flow patterns across the four valves were examined by pulsed, continuous-wave, and color Doppler imaging techniques. Regurgitation was detected in 124 (26.9%). Pulmonic regurgitation was most commonly found and was detected in 101 (21.9%) patients, tricuspid regurgitation in 29 (6.3%), and mitral regurgitation in 11 (2.4%). Aortic regurgitation was not found. Regurgitation of one valve occurred in 106 (23.0%) patients and of two valves in 18 (3.9%) patients. No patient had regurgitation of more than two valves. The prevalence of pulmonic regurgitation increased significantly with age (p less than 0.0001), whereas the prevalence of mitral, tricuspid, and bivalvular regurgitation did not change with age. Valvular regurgitation was trivial or mild in 87% of patients. Thus mild valvular regurgitation is commonly found in children with structurally normal hearts.     

Prevalence of physiological valvular regurgitation in hypertensive patients: echocardiographic and color Doppler study.

Since the advent of the Doppler color flow echocardiography, the presence of a small degree of insufficiency of the cardiac valves has been detected with relative frequency in structurally and functionally normal hearts. Data about this so-called 'physiological' regurgitation are presently available only in normotensive subjects and athletes. We therefore studied the prevalence of this phenomenon in a group of patients with essential hypertension compared to a population of normotensive subjects. To this purpose, a Doppler color flow echocardiographic study was performed in 130 essential hypertensive patients (72M/58F; age 44.2 +/- 13.5 years; BP 154.3 +/- 12.8/98.3 +/- 7.1 mm Hg) without any evidence of left ventricular hypertrophy or cardiopathy and in 100 normal subjects (59M/41F; age 41.2 +/- 14.8 years; BP 119.1 +/- 8.1/79.2 +/- 8.1 mm Hg). We conclude that in patients with essential hypertension the physiological regurgitant jets are present in one or more cardiac valves; moreover, the regurgitation of the mitral and aortic valve is found with more frequency than in the normotensive control group (36.1 vs. 27.0% and 17.7 vs. 11.0%, respectively). These data suggest that the increased afterload of the left ventricle may play an important role in the pathogenesis of even minor degree of insufficiency of the cardiac valves. As this finding does not appear to have a pathological relevance, the main clinical implication of this study is that it is not advisable to create a jatrogenic heart disease in the hypertensive patients routinely screened by the echo-Doppler technique.     

Comparison of high pulse repetition frequency and continuous wave Doppler echocardiography in the assessment of high flow velocity in patients with valvular stenosis and regurgitation

Continuous wave Doppler echocardiography has proved useful in detecting and quantitating the high velocity flow disturbances that characterize many stenotic and regurgitant valvular lesions. Pulsed Doppler echocardiography, in contrast, is limited in its ability to quantitate the high velocities that are detected. Recently, new pulsed Doppler systems have been developed that employ high pulse repetition frequencies and can theoretically measure higher flow velocities than those measured by the standard pulsed Doppler systems. To determine the ability of high pulse repetition frequency Doppler echocardiography to accurately measure high velocity flow signals in comparison with the continuous wave method, 80 patients undergoing routine echocardiographic examination for the assessment of valvular heart disease were studied using both techniques. A total of 113 high velocity flow disturbances were detected in 68 patients. In 41 instances, the maximal velocities by the two methods were within 0.5 m/s of each other. In 68 of the 113 high velocity lesions, however, the high pulse repetition frequency technique underestimated the peak velocity found with continuous wave Doppler echocardiography by more than 0.5 m/s. Comparison of the peak velocities recorded by the two methods for the total group showed no significant correlation (r = 0.04, p = NS). Comparison of the difference in peak velocities obtained by the two techniques with the maximal continuous wave velocity (n = 94, r = 0.70, slope = 0.71) suggested that the underestimation becomes greater as the peak velocity increases. Fifteen of the study patients with aortic stenosis subsequently underwent catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantitative assessment of pulmonary hypertension in patients with tricuspid regurgitation using continuous wave Doppler ultrasound

Doppler ultrasound examination was performed in 69 patients with a variety of cardiopulmonary disorders who were undergoing bedside right heart catheterization. Patients were classified into two groups on the basis of hemodynamic findings. Group I consisted of 20 patients whose pulmonary artery systolic pressure was less than 35 mm Hg and Group II consisted of 49 patients whose pulmonary artery systolic pressure was 35 mm Hg or greater. Tricuspid regurgitation was detected by Doppler ultrasound in 2 of 20 Group I patients and 39 of 49 Group II patients (p less than 0.001). Twenty-six of 27 patients with pulmonary artery systolic pressure greater than 50 mm Hg had Doppler evidence of tricuspid regurgitation. In patients with tricuspid regurgitation, continuous wave Doppler ultrasound was used to measure the velocity of the regurgitant jet, and by applying the Bernoulli equation, the peak pressure gradient between the right ventricle and right atrium was calculated. There was a close correlation between the Doppler gradient and the pulmonary artery systolic pressure measured by cardiac catheterization (r = 0.97, standard error of the estimate = 4.9 mm Hg). Estimating the right atrial pressure clinically and adding it to the Doppler-determined right ventricular to right atrial pressure gradient was not necessary to achieve accurate results. These findings indicate that tricuspid regurgitation can be identified by Doppler ultrasound in a large proportion of patients with pulmonary hypertension, especially when the pulmonary artery pressure exceeds 50 mm Hg. Calculation of the right ventricular to right atrial pressure gradient in these patients provides an accurate noninvasive estimate of pulmonary artery systolic pressure.     

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.     

Continuous wave Doppler echocardiographic evaluations of the severity of mitral regurgitation

To ascertain the usefulness of continuous wave Doppler echocardiography in evaluating the severity of mitral regurgitation (MR), 29 patients with MR and 10 normal subjects were examined. The patients were categorized in three groups according to the angiographic evidence of severity of MR. To analyze the flow velocity patterns of MR, the time to peak velocity index (time from onset of MR signal to peak flow velocity/duration of MR signal), the A/B ratio (the ratio of the first and second half of the systolic MR signal area), systolic peak velocity, and diastolic peak velocity were measured using continuous wave Doppler echocardiograms. The velocity patterns of MR differed significantly among the three groups. With severer MR, the flow velocity pattern showed an earlier appearance of the peak in systole, a steeper decrease in systole and a greater increase in early diastole. The time to peak velocity index was 55 +/- 7% (mean +/- SD) in mild MR, 42 +/- 6% in moderate MR and 35 +/- 5% in severe MR. This index shortened significantly in accord with the severity of MR (mild vs moderate MR: p less than 0.001, moderate vs severe MR: p less than 0.05). The A/B ratio was 1.06 +/- 0.12 in mild MR, 1.23 +/- 0.10 in moderate MR and 1.41 +/- 0.07 in severe MR. This ratio increased significantly with the severity of MR (mild vs moderate MR: p less than 0.01, moderate vs severe MR: p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Pulsed Doppler echocardiographic assessment of transmitral flow in pacing-induced angina pectoris

We analyzed transmitral flow using pulsed Doppler echocardiography during anginal attack provoked by atrial pacing in 11 patients with coronary artery disease (CAD). Left ventricular (LV) filling period was divided into 4 time intervals (Tr1: the time interval to peak velocity of rapid filling (peak R), Tr2: the time interval from peak R to the end of rapid filling, Ts: the time interval of slow filling, Ta: the time interval of atrial contraction). The velocity in each interval was integrated by planimeter as IR1, IR2, IS or IA which indicates relative filling volume in each interval. During angina, IR1 was unchanged due to prolongation of Tr1 (82 +/- 21 to 102 +/- 23 msec, p less than 0.02), despite a decrease in peak R (54 +/- 11 to 43 +/- 11 cm/sec, p less than 0.005), while IR2 decreased (5.8 +/- 1.9 to 4.3 +/- 1.4 cm, p less than 0.005) and IA increased (6.7 +/- 1.4 to 7.3 +/- 1.3 cm, p less than 0.005). In conclusion, these results suggested that in acute myocardial ischemia in CAD a decrease in transmitral flow from the time of peak R to the end of rapid filling (IR2) reflected the impairment of the LV rapid filling, which was incompletely compensated by an increase in atrial contraction.     

Quantification of aortic regurgitation using continuous and pulsed wave Doppler echocardiography

In a prospective blind study, continuous and pulsed wave Doppler echocardiography were used to predict the severity of angiographically assessed aortic regurgitation in 36 patients. High quality continuous wave spectral recordings of the regurgitant jet were obtained in 32 patients but four patients with mild aortic regurgitation had dropout of high velocity signals precluding accurate assessment. The deceleration slope of the peak to end-diastolic velocity measured by continuous wave Doppler, and pulsed wave Doppler mapping of the regurgitant jet in the left ventricle were compared with angiographic severity. The deceleration slope was significantly steeper in patients with severe rather than mild or moderate aortic regurgitation (3.65 +/- 1.04 vs. 1.89 +/- 0.42 vs. 1.52 +/- 0.59 m sec-2). A decay slope of greater than 3 m sec-2 was observed only in patients with 3+ or 4+ aortic regurgitation and a decay slope less than 1.2 m sec-2 was seen only in mild 1+ aortic regurgitation but there was considerable overlap between groups, making it difficult in individual cases to assess severity on the basis of the continuous wave deceleration slope. The pulsed wave Doppler technique was more time consuming, added little to the continuous wave Doppler assessment and underestimated severe regurgitation in almost 50% of cases. Hence, there are significant problems using either Doppler technique in quantitatively assessing aortic regurgitation.     

Doppler echocardiographic evaluation of mitral regurgitation

Evaluation of the severity and hemodynamic significance of mitral regurgitation remains an important and difficult problem. Cardiac ultrasound has emerged as the procedure of choice for the initial evaluation of mitral incompetence, as a result of its ability to confirm the diagnosis and provide a semiquantitative estimate of the severity of incompetence, determine its etiology, and assess the hemodynamic impact of the incompetence on ventricular function. This article reviews established as well as investigational methods of evaluating mitral incompetence by echocardiography and explores established and potential clinical applications of this evolving technology.