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

Echocardiographic assessment of aortic regurgitation: a narrative review

Aortic regurgitation (AR) is the third most frequently encountered valve lesion and may be caused by abnormalities of the valve cusps or the aorta. Echocardiography is instrumental in the assessment of AR as it enables the delineation of valvular morphology, the mechanism of the lesion and the grading of severity. Severe AR has a major impact on the myocardium and carries a significant risk of morbidity and mortality if left untreated. Established and novel echocardiographic methods, such as global longitudinal strain and three-dimensional echocardiography, allow an estimation of this risk and provide invaluable information for patient management and prognosis. This narrative review summarises the epidemiology of AR, reviews current practices and recommendations with regards to the echocardiographic assessment of AR and outlines novel echocardiographic tools that may prove beneficial in patient assessment and management.

Relation of Transthoracic Echocardiographic Aortic Regurgitation to Pressure Half-time and All-Cause Mortality

To evaluate the relation of aortic regurgitation (AR) pressure half-time (PHT) on transthoracic echocardiography (TTE) and all-cause mortality, we screened 118,647 baseline TTE reports from 2000 to 2017, to identify patients with any AR and PHT data. Patients with infective endocarditis or previous aortic valve replacement were excluded. The relation of baseline PHT on time to all-cause mortality was evaluated using Cox regression. A total of 2,653 patients were included (73.1 ± 14.3 years; 53.8% female; PHT, 530 ± 162 ms). Patients with shorter PHTs more frequently had 3-4+ AR (PHT ≤ 200 ms vs > 500 ms, 17.9% vs 0.6%, p < 0.0001). Diastolic parameters (E/e', E/A ratio, mitral valve deceleration time, and pulmonary artery systolic pressure) all significantly correlated with PHT (all p < 0.05). Over a median (IQR) follow-up of 8 (4 to 11 years), there were 799 (30.1%) deaths at a median (IQR) of 1.9 (0.4 to 4.3) years. On a univariate basis, a PHT ≤ 320 ms or > 750 ms was significantly related to increased mortality, even amongst those with nonsevere AR. After multivariable adjustment (in particular for E/e'), PHT was no longer significantly related to death. In conclusion, in this large, single center, retrospective study, AR PHT was not independently related to mortality. While a PHT ≤ 320 ms was associated with increased mortality in patients without severe AR, this relation was no longer significant after adjusting for diastolic functional variables. Thus, a PHT ≤ 320 ms in patients without significant AR may indicate prognostically-relevant diastolic dysfunction.

Prognosis of aortic valve disease following mitral valve surgery

Introduction

Little is known about the course of aortic valve disease in patients undergoing mitral valve surgery for rheumatic mitral valve disease. In addition, there are no guidelines regarding the appropriate treatment of mild aortic valve disease while replacing the mitral valve.

Aim

To evaluate the long-term outcome of aortic valve disease and the need for aortic valve surgery in patients with rheumatic mitral valve disease who underwent mitral valve surgery.

Material and methods

Twenty patients (6 male, 14 female; mean age: 23.4 years, range: 14-41) were followed after mitral valve surgery for a mean period of 14 years. All patients had rheumatic heart disease. Aortic valve function was assessed preoperatively by transthoracic echocardiography and during follow-up.

Results

At the time of mitral valve surgery, 11 (55%) patients had aortic valve disease with aortic regurgitation. Nine (45%) patients had no evidence of aortic valve disease. At second surgery, all patients had aortic valve disease (either pure regurgitation or with stenosis). Most had mild disease at the time of mitral valve surgery. Aortic valve replacement was needed after a mean period of 14.1 years (range: 3-26 years).

Conclusions

In patients with rheumatic heart disease, a noticeable number of patients have mild aortic valve disease at the time of mitral valve surgery. Only a few progress to severe disease, and aortic valve replacement is rarely needed after a long follow-up period.

Attitude after a mild aortic valve lesion during rheumatic mitral valve surgery

OBJECTIVE

We evaluated whether rheumatic aortic valve disease of mild degree should be treated in patients undergoing mitral valve surgery.

METHODS

From 1992 to 2010, 197 patients (aged 52 [19-82] years, male:female = 60:137) who had rheumatic mitral valve disease and mild aortic valve disease were enrolled. The aortic valve was untreated in 114 patients (no treatment group), repaired in 40 patients (aortic valvuloplasty group), and replaced in 43 patients (aortic valve replacement group).

RESULTS

Operative mortality occurred in 4 patients (2.0%). There were no differences in early mortality and postoperative complications among the 3 groups. Overall survival at 5, 10, and 15 years was 96.3%, 92.1%, and 85.7%, respectively. In the no treatment group, progression-free survival in significant aortic valve disease at 5, 10, and 15 years was 98.7%, 91.3%, and 81.1%, respectively. This was not superior in the aortic valvuloplasty group (85.9%, 77.6%, and 69.8%, respectively) than in the no treatment group. Freedom from aortic valve disease was lower in patients with aortic stenosis than in those with aortic regurgitation in univariate and multivariable analyses (P < .001). Reoperation was performed in 19 patients, including 2 aortic valve reoperations. Aortic valve-related event-free survival was similar among the 3 groups.

CONCLUSIONS

Mild aortic valve disease in patients undergoing rheumatic mitral valve surgery could be left untreated, because preventive aortic valve operation does not result in better clinical and echocardiographic outcomes.

Impact of concomitant aortic regurgitation on percutaneous mitral valvuloplasty: Immediate results, short-term, and long-term outcome

BACKGROUND

The aim of the study is to examine the effect of concomitant aortic regurgitation (AR) on percutaneous mitral valvuloplasty (PMV) procedural success, short-term, and long-term clinical outcome. No large-scale study has explored the impact of coexistent AR on PMV procedural success and outcome.

METHODS

Demographic, echocardiographic, and procedure-related variables were recorded in 644 consecutive patients undergoing 676 PMV at a single center. Mortality, aortic valve surgery (replacement or repair) (AVR), mitral valve surgery (MVR), and redo PMV were recorded during follow-up.

RESULTS

Of the 676 procedures performed, 361 (53.4%) had no AR, 287 (42.5%) mild AR, and 28 (4.1%) moderate AR. There were no differences between groups in the preprocedure characteristics, procedural success, or in the incidence of inhospital adverse events. At a median follow-up of 4.11 years, there was no difference in the overall survival rate (P = .22), MVR rate (P = .69), or redo PMV incidence (P = .33). The rate of AVR was higher in the moderate AR group (0.9% vs 1.9% vs 13%, P = .003). Mean time to AVR was 4.5 years and did not differ significantly between patients with no AR, mild AR, or moderate AR (2.9 +/- 2.1 vs 5.7 +/- 3.6 vs 4.1 +/- 2.5 years, P = .46).

CONCLUSIONS

Concomitant AR at the time of PMV does not influence procedural success and is not associated with inferior outcome. A minority of patients with MS and moderate AR who undergo PMV will require subsequent AVR on long-term follow-up. Thus, patients with rheumatic MS and mild to moderate AR remain good candidates for PMV.

64-Slice Multidetector Computed Tomography (MDCT) for Detection of Aortic Regurgitation and Quantification of Severity

BACKGROUND

Recent advances in 64-slice multidetector computed tomography (MDCT) provide an opportunity to assess coronary artery disease, left ventricular function and, potentially, valvular heart disease.

OBJECTIVE

To determine the ability of 64-MDCT to both detect and to quantify the severity of aortic regurgitation (AR), as compared with transthoracic echocardiography (TTE).

METHODS

We evaluated a total of 64 patients (43 males, mean age 63+/-11 years), 30 with varying severities of AR as assessed by TTE and 34 matched controls. The severity of AR by TTE was determined using the vena contracta, the ratio of jet to left ventricular outflow tract (LVOT) height, and the ratio of the jet to LVOT cross-sectional area. AR by MDCT was defined as a lack of coaptation of the aortic valve leaflets in diastole and, if detected, the maximum anatomic aortic regurgitant orifice was determined.

RESULTS

All 34 control patients without AR were correctly identified by MDCT. There were 14 patients with mild AR, 10 with moderate AR, and 6 with severe AR by TTE. Of these patients, MDCT correctly identified 21 patients with AR (sensitivity 70%, specificity 100%, positive predictive value [PPV] 100%, and negative predictive value [NPV] 79%). Anatomic regurgitant orifice area measured by MDCT correlated well with the TTE-derived vena contracta (r=0.79, P<0.001), ratio of jet to LVOT height (r=0.79, P<0.001), and ratio of jet to LVOT cross-sectional area (r=0.75, P<0.001).

CONCLUSIONS

Direct planimetric measurement of the aortic valve anatomic regurgitant orifice area on 64-MDCT provides an accurate, noninvasive technique for detecting and quantifying AR.

Valvular Heart Disease

Aortic regurgitation (AR) is characterized by diastolic reflux of blood from the aorta into the left ventricle (LV). Acute AR typically causes severe pulmonary edema and hypotension and is a surgical emergency. Chronic severe AR causes combined LV volume and pressure overload. It is accompanied by systolic hypertension and wide pulse pressure, which account for peripheral physical findings, such as bounding pulses. The afterload excess caused by systolic hypertension leads to progressive LV dilation and systolic dysfunction. The most important diagnostic test for AR is echocardiography. It provides the ability to determine the cause of AR and to assess the severity of AR and its effect on LV size, function, and hemodynamics. Many patients with chronic severe AR may remain clinically compensated for years with normal LV function and no symptoms. These patients do not require surgery but can be followed carefully for the onset of symptoms or LV dilation/dysfunction. Surgery should be considered before the LV ejection fraction falls below 55% or the LV end-diastolic dimension reaches 55 mm. Symptomatic patients should undergo surgery unless there are excessive comorbidities or other contraindications. The primary role of medical therapy with vasodilators is to delay the need for surgery in asymptomatic patients with normal LV function or to treat patients in whom surgery is not an option. The goal of vasodilator therapy is to achieve a significant decrease in systolic arterial pressure. Future therapies may focus on molecular mechanisms to prevent adverse LV remodeling and fibrosis.

[Doppler ultrasound and aortic regurgitation. Evaluation of the sensitivity and specificity of Doppler findings]

PURPOSE

The purpose of this study was to determine the sensitivity and specificity of arterial Doppler findings of aortic regurgitation to assess if the amplitude of changes of Doppler tracings can accurately quantify the degree of regurgitation.

PATIENTS AND METHODS

We analysed and compared the arterial Doppler tracings and echocardiograms of 250 patients.

RESULTS

Even if the obvious pitfall of vascular stenoses is avoided, the global sensitivity of arterial Doppler findings for aortic regurgitation remains weak (30%). However, our study demonstrates that it can reach 100% if only significant AR (> or =2/4) is taken into account. Since the clear false-positive cases have been carefully excluded from the very start, the specificity of the classical criteria already proves excellent (above 95%). It will reach perfection if additional simple criteria gathered from the data mentioned in this study are considered. Quantifying precisely the degree of aortic regurgitation on the basis of arterial Doppler tracings is impossible. Nevertheless, we show that it is easy to identify significant AR (> or =2/4) that should be further assessed with echocardiography.

CONCLUSION

Arterial Doppler sonography is unable to detect all cases of aortic regurgitation but those that are overlooked are not significant (1/4). If AR signs happen to be detected by arterial Doppler, the amplitude of the leak cannot be accurately determined based on tracing analysis. Yet, simple criteria will indicate whether it is important enough (> or =2/4) to require complementary echocardiogram, with well documented accuracy for morphological and hemodynamic evaluation.

The a-dip of aortic regurgitation

Echocardiography has become the diagnostic technique of choice for delineating the intracardiac hemodynamics in a host of pathophysiologic states. Pressures and flows can be estimated or measured with enough accuracy to allow for clinical decision-making. We present a case with an unusual Doppler echocardiographic finding and discuss its derivation.

Is prophylactic aortic valve replacement indicated during mitral valve surgery for mild to moderate aortic valve disease?

BACKGROUND

Determining the need for surgical treatment of coexisting mild to moderate aortic valve disease in patients referred for mitral valve surgery is often difficult. The purpose of this study was to assess long-term clinical outcome and the need for subsequent aortic valve replacement in patients with mild to moderate rheumatic aortic valve disease at the time of mitral valve surgery.

METHODS

A total of 275 patients (90 men and 185 women, mean age 43 years) with rheumatic disease who underwent mitral valve surgery were followed up for an average of 9 years. Patients were classified into two groups: those with coexisting mild to moderate aortic valve disease at the time of mitral valve surgery (141 patients, group A) and those without (134 patients, group B). Primary outcomes (death and subsequent aortic valve surgery) were compared between the two groups.

RESULTS

At the time of mitral valve surgery, 104 patients (74%) in group A had mild aortic regurgitation, 37 (26%) had moderate aortic regurgitation, 5 had (4%) mild aortic stenosis, and 2 (1%) had moderate aortic stenosis. At the end of follow-up, no patient had severe aortic valve disease. In all, 12 patients (5%) in group A had primary events (eight deaths and four subsequent aortic valve replacements), and 12 patients (9%) in group B had such events (12 deaths). According to Kaplan-Meier analysis, neither the survival rate nor the event-free survival rate differed significantly over the follow-up period between the two groups.

CONCLUSIONS

In most patients who have mild to moderate rheumatic aortic valve disease at the time of mitral valve surgery, the long-term outcome is comparable to that of subjects without aortic valve disease at the time of mitral valve surgery. Subsequent aortic valve replacement is rarely needed after a long follow-up period.

Measurement of aortic valve anatomic regurgitant area using transesophageal echocardiography: implications for the quantitation of aortic regurgitation

BACKGROUND

Various echocardiographic methods for the assessment of the severity of the aortic regurgitation (AR) by have been described with no general consensus.

AIM

To assess the feasibility and reproducibility of direct planimetric measurement of the end-diastolic gap between aortic cusps on the transesophageal echocardiography (TEE) images in patients with AR. We also analyzed the correlation of this anatomic aortic regurgitanty area with angiographic AR severity.

METHODS

Ninety patients (38 males, 52 females, mean age 41 +/- 24 years) with AR who underwent TEE and contrast aortography in a single institution. The AR was graded angiographically as mild (n = 45), moderate (n = 31), and severe (n = 14). The anatomic regurgitant area was measured on the end-diastolic short-axis TEE images of the aortic valve by planimetering the central gap bordered by the commisural edges of the aortic cusps.

RESULTS

The intraobserver and interobserver variability for the measurement of aortic anatomic regurgitant area were small (mean absolute differences 0.01 +/- 0.01 cm(2), and 0.015 +/- 0.013 cm(2), respectively). The average values of anatomic regurgitant area for angiographically mild, moderate, and severe AR were 0.15 +/- 0.05 cm(2), 0.30 +/- 0.08 cm(2), and 0.68 +/- 0.33 cm(2), respectively (P <.001). When the anatomic regurgitant area was graded as small (> 0.2 cm(2)), moderate (> 0.2 and > 0.4 cm(2)) and large (> 0.4 cm(2)), the sensitivity, specificity, positive and negative predictive value, and the diagnostic accuracy for predicting the angiographically mild AR were 85%, 97%, 97%, 87%, and 91%, respectively. For the moderate angiographic AR the same values were 84%, 92%, 81%, 93%, and 90%, and for the severe angiographic AR they were 98%, 93%, 93%, 98% and 97%.

CONCLUSION

The planimetric measurement of aortic anatomic regurgitant area by TEE is feasible and reproducible for the assessment of the severity of AR.

Usefulness of beta blocker therapy in patients with Takayasu arteritis and moderate or severe aortic regurgitation

The objective of the present study was to evaluate the benefit of beta-blocker therapy for patients with Takayasu arteritis complicated by moderate or severe aortic regurgitation. Clinical and echocardiographic evaluation was performed in 20 Japanese women in a follow-up period of 7.0 +/- 2.0 years. The patients were divided into 2 groups: Group A (n=10) patients who did not receive beta-blockers, and Group B (n=10) patients treated with long-term (5.1 +/- 1.6 years) therapeutic doses of beta-blockers. Left ventricular wall thickness increased significantly in all Takayasu patients who did not receive beta-blockers. Consequently, a remarkable increment in left ventricular mass took place (232 +/- 59 to 361 +/- 79 g; p < 0.005). In the same group, progressive worsening of the symptoms, with no reduction in the percent fractional shortening, was observed in 2 patients, while reduction of this last index was present in 1 asymptomatic patient. On the other hand, among the patients who were treated with beta-blockers, left ventricular mass still increased in 6 cases, while it clearly decreased in the other 4 cases (290 +/- 171 to 284 +/- 61 g; NS). The increment in wall thickness or left ventricular mass observed among patients with beta-blocker therapy was clearly less than the one registered among those who had not received beta-blockers. Furthermore, no worsening of the symptoms and/or left ventricular performance was observed during the follow-up period for patients receiving beta-blockers. We conclude that beta-blocker therapy can slow and even reverse the progression of left ventricular hypertrophy in patients with Takayasu arteritis complicated by moderate or severe aortic regurgitation. The mechanism still needs to be elucidated. We believe an effective reduction in the excessive afterload imposed on the left ventricle to be most likely responsible, but cardiac beta-receptor up-regulation might also be involved. Deterioration of the clinical status and/or impairment of left ventricular function were not associated with beta-blocker therapy in our patients. Therefore, these agents can be used safely alone or in addition to standard anti-hypertensive therapy when attempting to reduce excessive afterload, in spite of the presence of severe aortic regurgitation.

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.

Timing of surgery in chronic aortic regurgitation

When deciding on therapy for aortic regurgitation (AR), it is imperative to distinguish between acute and chronic AR. Symptoms and echocardiographic findings are essential in distinguishing acute from chronic AR and in assessing the severity. Vasodilators have been shown to be helpful in treating patients with chronic severe AR. The timing of aortic valve replacement in chronic severe AR remains controversial. Symptoms, left ventricular function, and response to exercise have been shown to be the most important prognostic indicators.

Aortic regurgitation: quantitative methods by echocardiography

Quantification of aortic regurgitation (AR) is a common and difficult clinical problem. The severity of regurgitation has traditionally been estimated with the use of contrast aortography, which is impractical as a screening tool or for serial examinations. In the past two decades, Doppler echocardiography has emerged as an important tool in the quantification of AR. Pulsed Doppler mapping of the depth of the regurgitant jet into the left ventricle was one of the initial echocardiographic methods used for this purpose. The slope and pressure (or velocity) half-time of continuous-wave Doppler profiles of regurgitant jets are also useful. These Doppler techniques may be used to determine the regurgitant volume or regurgitant fraction in patients with AR. The use of color Doppler to measure the height (or cross-sectional area) of the regurgitant jet relative to the height (cross-sectional area) of the left ventricular outflow tract is both sensitive and specific in the quantification of AR. More recently, the continuity principle has been used to determine the effective aortic regurgitant orifice area, which increases as AR becomes more severe. Although this is a promising tool, calculation of this value is not yet common practice in most echocardiography laboratories. Although no single echocardiographic technique is without limitations, all have some validity, and it is reasonable to use a combination of them to obtain a composite estimate of the severity of AR.

Flow convergence flow rates from 3-dimensional reconstruction of color Doppler flow maps for computing transvalvular regurgitant flows without geometric assumptions: An in vitro quantitative flow study

OBJECTIVE

This study was designed to develop and test a 3-dimensional method for direct measurement of flow convergence (FC) region surface area and for quantitating regurgitant flows with an in vitro flow system.

BACKGROUND

Quantitative methods for characterizing regurgitant flow events such as flow convergence with 2-dimensional color flow Doppler imaging systems have yielded variable results and may not be accurate enough to characterize those more complex spatial events.

METHOD

Four differently shaped regurgitant orifices were studied: 3 flat orifices (circular, rectangular, triangular) and a nonflat one mimicking mitral valve prolapse (all 4 orifice areas = 0.24 cm(2)) in a pulsatile flow model at 8 to 9 different regurgitant flow rates (10 to 50 mL/beat). An ultrasonic flow probe and meter were connected to the flow model to provide reference flow data. Video composite data from the color Doppler flow images of the FC were reconstructed after computer-controlled 180 degrees rotational acquisition was performed. FC surface area (S cm(2)) was calculated directly without any geometric assumptions by measuring parallel sliced flow convergence arc lengths through the FC volume and multiplying each by the slice thickness (2.5 to 3.2 mm) over 5 to 8 slices and then adding them together. Peak regurgitant flow rate (milliliters per second) was calculated as the product of 3-dimensional determined S (cm(2)) multiplied by the aliasing velocity (centimeters per second) used for color Doppler imaging.

RESULTS

For all of the 4 shaped orifices, there was an excellent relationship between actual peak flow rates and 3-dimensional FC-calculated flow rates with the direct measurement of the surface area of FC (r = 0.99, mean difference = -7.2 to -0.81 mL/s, % difference = -5% to 0%), whereas a hemielliptic method implemented with 3 axial measurements of the flow convergence zone from 2-dimensional planes underestimated actual flow rate by mean difference = -39.8 to -18.2 mL/s, % difference = -32% to -17% for any given orifice.

CONCLUSIONS

Three-dimensional reconstruction of flow based on 2-dimensional color Doppler may add quantitative spatial information, especially for complex flow events. Direct measurement of 3-dimensional flow convergence surface areas may improve accuracy for estimation of the severity of valvular regurgitation.

The natural history of aortic valve disease after mitral valve surgery

OBJECTIVES

The present study evaluates the long-term course of aortic valve disease and the need for aortic valve surgery in patients with rheumatic mitral valve disease who underwent mitral valve surgery.

BACKGROUND

Little is known about the natural history of aortic valve disease in patients undergoing mitral valve surgery for rheumatic mitral valve disease. In addition there is no firm policy regarding the appropriate treatment of mild aortic valve disease while replacing the mitral valve.

METHODS

One-hundred thirty-one patients (44 male, 87 female; mean age 61+/-13 yr, range 35 to 89) were followed after mitral valve surgery for a mean period of 13+/-7 years. All patients had rheumatic heart disease. Aortic valve function was assessed preoperatively by cardiac catheterization and during follow-up by transthoracic echocardiography.

RESULTS

At the time of mitral valve surgery, 59 patients (45%) had mild aortic valve disease: 7 (5%) aortic stenosis (AS), 58 (44%) aortic regurgitation (AR). At the end of follow-up, 96 patients (73%) had aortic valve disease: 33 AS (mild or moderate except in two cases) and 90 AR (mild or moderate except in one case). Among patients without aortic valve disease at the time of the mitral valve surgery, only three patients developed significant aortic valve disease after 25 years of follow-up procedures. Disease progression was noted in three of the seven patients with AS (2 to severe) and in six of the fifty eight with AR (1 to severe). Fifty two (90%) with mild AR remained stable after a mean follow-up period of 16 years. In only three patients (2%) the aortic valve disease progressed significantly after 9, 17 and 22 years. In only six patients of the entire cohort (5%), aortic valve replacement was needed after a mean period of 21 years (range 15 to 33). In four of them the primary indication for the second surgery was dysfunction of the prosthetic mitral valve.

CONCLUSIONS

Our findings indicate that, among patients with rheumatic heart disease, a considerable number of patients have mild aortic valve disease at the time of mitral valve surgery. Yet most do not progress to severe disease, and aortic valve replacement is rarely needed after a long follow-up period. Thus, prophylactic valve replacement is not indicated in these cases.

Influence of Heart Rate on Doppler Aortic Regurgitant Velocity Curve: Clinical Role of Heart Rate Correction of Regurgitant Pressure Half-Time

Because it was recently suggested that pressure half-time (PHT) of aortic regurgitant velocity curve is influenced by heart rate (HR), we retrospectively analyzed 76 patients with aortic regurgitation (AR) to determine whether PHT independently correlates with HR and whether HR correction of PHT can be clinically useful. PHT correlated significantly (P < 0.001) with color Doppler relative regurgitant jet height (r = -0.62), with angiographic grading (r = -0.65), and with HR (r = -0.54); such correlations were confirmed by multivariate analysis. Tachycardia influences aortic velocity curve more than bradycardia, and this effect is more evident in patients with milder regurgitation. Two methods of HR correction of PHT were tested: relative PHT (PHT/diastolic time x 100) and corrected PHT (PHT/ radicalRR): only corrected PHT was independently related to both relative regurgitant jet height and angiographic grading (P < 0.001). HR correction of PHT by corrected PHT was of limited clinical usefulness: in fact, in the entire study population, the accuracy of the usual cutoff (< 300 msec) in detecting relevant AR was not improved by corrected PHT. However, in patients with higher HR (>/= 85 beats/min), in whom the effect of HR on aortic velocity curve appeared to be greater, corrected PHT was superior to PHT because the cutoff value of < 300 msec showed a good specificity (100%), a moderate sensitivity (66%), and a good accuracy (80%) in detecting relevant AR. Corrected PHT can be useful to confirm AR severity when a short PHT is observed in tachycardic patients.

An integrated approach to the quantification of aortic regurgitation by Doppler echocardiography

BACKGROUND

Although different Doppler methods have been proposed for the quantification of aortic regurgitation, no study has prospectively compared these methods with each other and their correlation with angiography. The aim of this study was to prospectively analyze the usefulness of different Doppler echocardiography parameters by testing all such parameters in each patient.

METHODS

Fifty-one patients with aortic regurgitation underwent 2-dimensional and Doppler echocardiographic studies and catheterization. The following Doppler indexes were analyzed and compared with aortography. Color Doppler: (1) jet color height/left ventricular outflow tract height in parasternal long-axis view, and (2) jet color area/left ventricular outflow tract area in short-axis view. Continuous Doppler: (3) regurgitant flow pressure half-time, (4) regurgitant flow time velocity integral (in centimeters), and (5) regurgitant flow time velocity integral (in centimeters)/diastolic period (in milliseconds). Pulsed Doppler in thoracic and abdominal aorta: (6) time velocity integral of diastolic reverse flow (in centimeters), (7) time velocity integral of systolic anterograde flow/integral of diastolic reverse flow, (8) (time velocity integral of diastolic reverse flow/diastolic period) x 100, and (9) diastolic reverse flow duration/diastolic period (as a percentage). We compared these parameters with severity of regurgitation measured by angiography and classified as mild, moderate, or severe.

RESULTS

The most useful parameters were (1) jet color height/left ventricular outflow tract height (correctly classified 42 of 49 patients), (2) (time velocity integral of diastolic reverse flow/diastolic period) x 100 in the thoracic aorta (correctly classified 41 of 46 patients), and (3) (time velocity integral of diastolic reverse flow/diastolic period) x 100 in the abdominal aorta (correctly classified 42 of 49 patients). Sequential integration of these 3 parameters correctly classified 96% of patients (44 of 46 patients) and was achieved in 90% of cases.

CONCLUSION

An integrated combination of several Doppler parameters can quickly and accurately classify the degree of aortic regurgitation as determined by angiography.

Accurate noninvasive estimation of left ventricular end-diastolic pressure: comparison with catheterization

We evaluated the accuracy of a new Doppler-based method using the mitral regurgitant velocity at the time of aortic valve opening for the noninvasive estimation of left ventricular end-diastolic pressure. Sixty unselected patients were studied immediately before routine catheterization. Invasive left ventricular end-diastolic pressure was obtained using a fluid-filled pig-tail catheter. Noninvasive estimation of left ventricular pressure at aortic valve opening was taken as systemic diastolic pressure using an automated cuff. Noninvasive left ventricular end-diastolic pressure was calculated as diastolic blood pressure--4 x (mitral regurgitant velocity at aortic opening)2. Those making noninvasive determinations were blinded to catheterization results. An adequate mitral regurgitant Doppler recording was obtained in 24 patients (40%). In patients with a left ventricular end-diastolic pressure greater than 15 mm Hg the yield was 65%. Left ventricular end-diastolic pressures ranged from 4 mm Hg to 30 mm Hg. Bland and Altman analysis revealed no systematic bias and close agreement was found, with individual discrepancies not exceeding 5 mm Hg.

Hemodynamic changes of aortic regurgitation

Hemodynamic changes associated with acute AR include a rapid increase in LV pressures during diastole, markedly elevated pressures at end diastole, and premature closure of the mitral valve. Systemic diastolic pressures may be low, but there is a minimal increase in pulse pressure. In very severe cases of acute AR, cardiac output may decrease, leading to hypotension. In chronic AR, the LV remodels to accommodate the regurgitant volume flow, and stroke volume increases to maintain effective forward blood flow. These adaptations lead to a dilated LV, a widened pulse pressure, and a low diastolic blood pressure, which are the classic findings of chronic AR.

Direct measurement of three-dimensionally reconstructed flow convergence surface area and regurgitant flow in aortic regurgitation: in vitro and chronic animal model studies

BACKGROUND

Evaluation of flow convergence (FC) with two-dimensional (2D) imaging systems may not be sufficiently accurate to characterize these often asymmetric, complex phenomena. The aim of this study was to validate a three-dimensional (3D) method for determining the severity of aortic regurgitation (AR) in an experimental animal model.

METHODS AND RESULTS

In six sheep with surgically induced chronic AR, 20 hemodynamically different states were studied. Instantaneous regurgitant flow rates were obtained by aortic and pulmonary electromagnetic flow meters. Video composite data of color Doppler flow mapping images were transferred into a TomTec computer after computer-controlled 180 degrees rotational acquisition. Direct measurement of the 3D reconstructed FC surface areas as well as measurements of FC areas estimated with 2D methods with hemispherical and hemielliptical assumptions were performed, and values were multiplied by the aliasing velocity to obtain peak regurgitant flow rates. There was better agreement between 3D and electromagnetically derived flow rates than there was between the 2D and the reference values (r=.94, y=1.0x-0.16, difference=0.02 L/min for the 3D method; r=.80, y=1.6x-0.3, difference=1.2 L/min for the 2D hemispherical method; r=.75, y=0.90x+0.2, difference=-0.20 L/min for the 2D hemielliptical method).

CONCLUSIONS

Without any geometrical assumption, the 3D method provided better delineation of the FC zones and direct measurements of FC surface areas, permitting more accurate quantification of the severity of AR than the 2D methods.

Calculation of aortic regurgitant volume by a new digital Doppler color flow mapping method: an animal study with quantified chronic aortic regurgitation

OBJECTIVES

The aim of the present study was to quantitate aortic regurgitant volume and regurgitant fraction in a chronic animal model with surgically created aortic regurgitation using a new semiautomated color Doppler flow calculation method.

BACKGROUND

The conventional noninvasive methods for evaluating the severity of aortic regurgitation have not been accepted widely nor compared with truly quantitative reference standards.

METHODS

Eight to 20 weeks after aortic regurgitation was surgically induced in six sheep, a total of 22 hemodynamic states were studied. Electromagnetic flow probes and meters provided reference flow data. Epicardial color Doppler echocardiographic studies were performed to image left ventricular outflow tract forward and aortic regurgitant blood flows. The new method digitally integrated spatial and temporal color flow velocity data for left ventricular outflow tract forward flow and ascending aortic regurgitant flow. The pulsed Doppler method using the velocity-time integral was also used to obtain regurgitant volumes and regurgitant fractions.

RESULTS

Regurgitant volumes and regurgitant fractions by the new method agreed well with those obtained electromagnetically, whereas the pulsed Doppler method overestimated these reference data (mean [+/-SD] difference 0.23 +/- 2.9 ml vs. 11 +/- 5.8 ml, p < 0.0001 for regurgitant volume; mean difference 1.2 +/- 7.6% vs. 19 +/- 13%, p < 0.0001 for regurgitant fraction).

CONCLUSIONS

This animal study, using strictly quantified aortic regurgitant volumes, demonstrated that the digital color Doppler method provides accurate aortic regurgitant volumes and regurgitant fractions without cumbersome measurements.

Effective regurgitant orifice area by the color Doppler flow convergence method for evaluating the severity of chronic aortic regurgitation. An animal study

BACKGROUND

The aim of the present study was to evaluate dynamic changes in aortic regurgitant (AR) orifice area with the use of calibrated electromagnetic (EM) flowmeters and to validate a color Doppler flow convergence (FC) method for evaluating effective AR orifice area and regurgitant volume.

METHODS AND RESULTS

In 6 sheep, 8 to 20 weeks after surgically induced AR, 22 hemodynamically different states were studied. Instantaneous regurgitant flow rates were obtained by aortic and pulmonary EM flowmeters balanced against each other. Instantaneous AR orifice areas were determined by dividing these actual AR flow rates by the corresponding continuous wave velocities (over 25 to 40 points during each diastole) matched for each steady state. Echo studies were performed to obtain maximal aliasing distances of the FC in a low range (0.20 to 0.32 m/s) and a high range (0.70 to 0.89 m/s) of aliasing velocities; the corresponding maximal AR flow rates were calculated using the hemispheric flow convergence assumption for the FC isovelocity surface. AR orifice areas were derived by dividing the maximal flow rates by the maximal continuous wave Doppler velocities. AR orifice sizes obtained with the use of EM flowmeters showed little change during diastole. Maximal and time-averaged AR orifice areas during diastole obtained by EM flowmeters ranged from 0.06 to 0.44 cm2 (mean, 0.24 +/- 0.11 cm2) and from 0.05 to 0.43 cm2 (mean, 0.21 +/- 0.06 cm2), respectively. Maximal AR orifice areas by FC using low aliasing velocities overestimated reference EM orifice areas; however, at high AV, FC predicted the reference areas more reliably (0.25 +/- 0.16 cm2, r = .82, difference = 0.04 +/- 0.07 cm2). The product of the maximal orifice area obtained by the FC method using high AV and the velocity time integral of the regurgitant orifice velocity showed good agreement with regurgitant volumes per beat (r = .81, difference = 0.9 +/- 7.9 mL/beat).

CONCLUSIONS

This study, using strictly quantified AR volume, demonstrated little change in AR orifice size during diastole. When high aliasing velocities are chosen, the FC method can be useful for determining effective AR orifice size and regurgitant volume.

Evaluation of aortic regurgitation with digitally determined color Doppler-imaged flow convergence acceleration: a quantitative study in sheep

OBJECTIVES

The aim of the present study was to validate a digital color Doppler-based centerline velocity/distance acceleration profile method for evaluating the severity of aortic regurgitation.

BACKGROUND

Clinical and in vivo experimental applications of the flow convergence axial centerline velocity/distance profile method have recently been used to estimate regurgitant flow rates and regurgitant volumes in the presence of mitral regurgitation.

METHODS

In six sheep, a total of 19 hemodynamic states were obtained pharmacologically 14 weeks after the original operation in which a portion of the aortic noncoronary (n = 3) or right coronary (n = 3) leaflet was excised to produce aortic regurgitation. Echocardiographic studies were performed to obtain complete proximal axial flow acceleration velocity/distance profiles during the time of peak regurgitant flow (usually early in diastole) for each hemodynamic state. For each steady state, the severity of aortic regurgitation was assessed by measurement of the magnitude of the regurgitant flow volume/beat, regurgitant fraction and instantaneous regurgitant flow rates determined by using both aortic and pulmonary artery electromagnetic flow probes.

RESULTS

Grade I regurgitation (regurgitant volume/beat < 15 ml, six conditions), grade II regurgitation (regurgitant volume/beat between 16 ml and 30 ml, five conditions) and grade III-IV regurgitation (regurgitant volume/beat > 30 ml, eight conditions) were clearly separated by using the color Doppler centerline velocity/distance profile domain technique. Additionally, an equation for correlating "a" (the coefficient from the multiplicative curve fit for the velocity/distance relation) with the peak regurgitant flow rates (Q [liters/min]) was derived showing a high correlation between calculated peak flow rates by the color Doppler method and the actual peak flow rates (Q = 13a + 1.0, r = 0.95, p < 0.0001, SEE = 0.76 liters/min).

CONCLUSIONS

This study, using quantified aortic regurgitation, demonstrates that the flow convergence axial centerline velocity/distance acceleration profile method can be used to evaluate the severity of aortic regurgitation.

Heart murmurs in horses: determining their significance with echocardiography

Physiological flow murmurs occur frequently in horses and may be difficult to distinguish from murmurs associated with underlying cardiac disease. The significance of heart murmurs auscultated in horses is often difficult to determine if the horse is not exhibiting any clinical signs or if the signs, such as poor performance, are nonspecific. A complete echocardiographic examination (M-mode, 2-dimensional (2-D) and Doppler) provides an objective assessment of the severity of the horse's underlying cardiac disease. Valvular regurgitation and ventricular septal defects (VSDs) occur frequently and may impair performance, result in the horse's premature demise or have no apparent effect on the horse's life expectancy or performance capabilities. The echocardiographic findings that are used to formulate a prognosis for longevity and performance in horses with valvular regurgitation include the abnormalities detected on the valve leaflets, degree of cardiac chamber enlargement, severity of the resultant volume overload, size of the regurgitant jet, and relative relationship of jet size to chamber size. The echocardiographic findings that are used to formulate a prognosis for horses with VSDs are the number, size and location of the defect(s), degree of left ventricular volume overload, maximal velocity and direction of shunt flow through the defect and the presence and severity of concurrent valvulus regurgitation. Knowledge of the natural progression of the common types of cardiovascular disease in horses, coupled with the echocardiographic findings, clinical history and owner's or trainer's expectations can help the veterinarian form an accurate prognosis for life and performance in horses with heart murmurs.

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

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): FVIMA/FVIOT = 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).(FVIMA/FVIOT). 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.

Quantification of left-side intracardiac pressures and gradients using mitral and aortic regurgitant velocities by simultaneous left and right catheterization and continuous-wave Doppler echocardiography

Noninvasive determination of left-side intracardiac pressures is of clinical importance in many cardiac diseases. To test the reliability and accuracy of left-side intracardiac pressure measurements by continuous-wave Doppler echocardiography, using left-side valvular regurgitations, 47 patients with mitral regurgitation, with or without associated aortic regurgitation, underwent simultaneous Doppler and left and right catheterization. Doppler-derived left atrial and ventricular end-diastolic pressures were respectively estimated by subtracting mitral regurgitant gradient from systolic blood pressure and by diastolic blood pressure minus aortic regurgitant gradient. There were high correlations of mitral (r = 0.961) and aortic regurgitant gradients (r = 0.896) and of left atrial (r = 0.945) and ventricular end-diastolic pressures (r = 0.854) between noninvasive and invasive measurements. Also, agreement analyses showed that there was close agreement between the two technical measurements for each parameter. The present study concluded that continuous-wave Doppler echocardiography provides a reliable and accurate method for the noninvasive evaluation of left-side intracardiac pressures and gradients in patients with mitral and aortic regurgitations.

Limitations of color flow Doppler imaging in the quantification of valvular regurgitation: velocity of regurgitant jet, rather than volume, determines size of color Doppler image

The objective of this study was to determine the validity of estimation of regurgitant volume by visual assessment of color flow Doppler display. An experimental apparatus was designed that is capable of ejecting precise volumes of echogenic material from one chamber to another under continuous color flow Doppler monitoring. The velocity of flow was altered independently by changing either the size of the orifice through which flow occurred or the ejection rate. In this manner the differential effects of volume and velocity on the color flow Doppler image could be examined. The maximum area encompassed by the color flow Doppler pattern for each ejection was planimetered by using commercially available on-line software. In addition the reviewer in each case applied a subjective grade to the appearance of the color flow jet (1+ to 4+). Comparison was then made of the color flow Doppler appearance of equal volumes flowing at different velocities and of different volumes flowing at different velocities. In the initial series a solution of agitated hetasarch was used. When equal volumes were imaged at different velocities the higher-velocity jet appeared larger, both subjectively (3+ vs 1+) and by measuring the area encompassed in the Doppler flow profile (40.3 +/- 1.8 vs 22.0 +/- 1.4 cm2, p = 0.0001). Furthermore, when different volumes were imaged at different velocities, the smaller volume (3 ml vs 6 ml) appeared larger when it was flowing at higher velocity (3+ vs 2+, 40.3 +/- 1.8 vs 32.4 +/- 1.3 cm2, p = 0.0006). These experiments were repeated with blood, confirming the results of the initial study.(ABSTRACT TRUNCATED AT 250 WORDS)

Semiquantitation of aortic regurgitation by different Doppler echocardiographic techniques and comparison with ultrafast computed tomography

Fourteen patients with chronic aortic regurgitation were studied by several two-dimensional and Doppler echocardiographic methods to determine the severity of aortic regurgitation. Semiquantitation of aortic regurgitation was performed by various color-flow imaging measurements, diastolic half-time of the continuous-wave regurgitation jet, and pulsed-wave velocity curve in the descending aorta. These measurements were compared with regurgitant volume and fraction by ultrafast computed tomography. All Doppler methods demonstrated a significant correlation for severity of aortic regurgitation with regurgitant fraction by ultrafast computed tomographic scanning, but scatter was present with each method. The methods with the closest correlation were at the lowest level of obtainable results. In clinical practice, all Doppler methods must be used to determine the severity of aortic regurgitation.

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.

The effects of regurgitant orifice size, chamber compliance, and systemic vascular resistance on aortic regurgitant velocity slope and pressure half-time

The determinants of the aortic regurgitant velocity profile have been investigated using computer and in vitro simulations in which regurgitant orifice area, ventricular and aortic compliance, and systemic vascular resistance could be independently varied. In the study, regurgitant fraction was altered, either by changing the size of the regurgitant orifice or by holding the regurgitant orifice constant and changing chamber compliance or systemic vascular resistance. Upon increasing regurgitant fraction by increasing the size of the regurgitant orifice, the slope got steeper and the pressure half-time shortened, the response anticipated in current clinical practice. However, when the regurgitant orifice was kept constant and regurgitation fraction was increased by increasing the systemic vascular resistance or by increasing the compliance of the left ventricle, slope became less steep and pressure half-time lengthened. Multivariate analysis was used to quantify the relationship of regurgitant fraction to slope and pressure half-time. When orifice area was allowed to vary, slope was related directly (multiple r = 0.78, p less than 0.001) and half-time was related inversely (multiple r = 0.66, p less than 0.001) to regurgitant fraction. With the orifice area fixed, however, directionally opposite responses were seen; slope varied inversely (multiple r = 0.87, p less than 0.001), whereas half-time varied directly (multiple r = 0.88, p less than 0.001) with regurgitant fraction. This study suggests that the utility of the slope and pressure half-time of the regurgitant velocity tracing in clinical practice relates to their ability to discriminate regurgitant orifices of differing sizes.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Comparison of cardiac catheterization and Doppler echocardiography in the decision to operate in aortic and mitral valve disease

Clinical decisions utilizing either Doppler echocardiographic or cardiac catheterization data were compared in adult patients with isolated or combined aortic and mitral valve disease. A clinical decision to operate, not operate or remain uncertain was made by experienced cardiologists given either Doppler echocardiographic or cardiac catheterization data. A prospective evaluation was performed on 189 consecutive patients (mean age 67 years) with valvular heart disease who were being considered for surgical treatment on the basis of clinical information. All patients underwent cardiac catheterization and detailed Doppler echocardiographic examination. Three sets of two cardiologist decision makers who did not know patient identity were given clinical information in combination with either Doppler echocardiographic or cardiac catheterization data. The combination of Doppler echocardiographic and clinical data was considered inadequate for clinical decision making in 21% of patients with aortic and 5% of patients with mitral valve disease. The combination of cardiac catheterization and clinical data was considered inadequate in 2% of patients with aortic and 2% of patients with mitral valve disease. Among the remaining patients, the cardiologists using echocardiographic or angiographic data were in agreement on the decision to operate or not operate in 113 (76% overall). When the data were analyzed by specific valve lesion, decisions based on Doppler echocardiography or catheterization were in agreement in 92%, 90%, 83% and 69%, respectively, of patients with aortic regurgitation, mitral stenosis, aortic stenosis and mitral regurgitation. Differences in cardiac output determination, estimation of valvular regurgitation and information concerning coronary anatomy were the main reasons for different clinical management decisions. These results suggest that for most adult patients with aortic or mitral valve disease, alone or in combination, Doppler echocardiographic data enable the clinician to make the same decision reached with catheterization data.

The value of Doppler echocardiography in the management of patients with valvular heart disease: analysis of one year of clinical practice

Management recommendations based on Doppler echocardiographic examination and cardiac catheterization were compared in a prospective study in 100 consecutive patients who were admitted for evaluation and treatment of suspected valvular heart disease during 1988. Management recommendations were provided independently after both Doppler echocardiography and cardiac catheterization by different and blinded investigators. Criteria for severe (clinically significant) and moderate to mild (insignificant) valvular lesions and management recommendations were agreed on in advance. There was disagreement on the severity of aortic stenosis based on the aortic valve area and maximum instantaneous pressure gradient in 1 of 54 patients, which resulted in differing management recommendations. Mitral stenosis was severe (valve area less than or equal to 1 cm2) at Doppler echocardiography but not at cardiac catheterization in 5 of 14 patients. Because pulmonary artery pressure increase during exercise at cardiac catheterization also suggested severe obstruction, management recommendations were similar. There was a potentially significant disagreement on the severity of aortic regurgitation in 9 of 76 patients and of mitral regurgitation in 14 of 90 patients; however, this did not produce differing management recommendations because with most patients coexistent valvular lesions or an impaired ventricular function mainly determined the ultimate management decision. Although of good quality, Doppler echocardiographic examination was nonconclusive for clinical decision-making in 15% of the study population because of uncertainty about the severity of mitral regurgitation or aortic regurgitation or because of problems in assessing the degree of left ventricular dysfunction in patients with severe regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)