Quantitation of mitral regurgitation by transesophageal echocardiography with Doppler color flow mapping: correlation with cardiac catheterization

Clinical characteristics and long-term outcomes of Libman-Sacks endocarditis in patients with systemic lupus erythematosus

OBJECTIVE

Treatment of Libman-Sacks (LS) endocarditis in patients with systemic lupus erythematosus (SLE) is challenging due to the lack of data. This study aimed to identify the clinical characteristics of SLE patients and LS endocarditis, and to investigate the treatment and prognosis of LS endocarditis.

METHODS

Of all the patients with SLE who underwent echocardiography between 2010 and 2019, 11 and 29 patients with and without LS endocarditis, respectively, were included. We compared the inflammatory and thrombotic profiles between patients with and without LS endocarditis, and investigated the treatment and long-term outcome of LS endocarditis.

RESULTS

No significant differences were observed in disease activity, clinical characteristics and inflammatory marker levels between patients with and without LS endocarditis. Patients with LS endocarditis had a significantly higher prevalence of antiphospholipid antibody (aPL) but a lower prevalence of SLE-specific antibody. Triple positivity of aPL was found in 72.7% and 13.8% of patients with and without LS endocarditis, respectively. Of 11 patients with LS endocarditis, six patients received anticoagulation therapy, and five patients received augmented immunosuppressive therapies. One patient who did not receive anticoagulation therapy developed cerebral infarction. Nine (82%) patients with LS endocarditis were classified as having antiphospholipid syndrome (APS). Despite the residual vegetation and valve dysfunction, surgical intervention was not required during the follow-up period of 56.8 months.

CONCLUSION

A significant correlation was observed between APS and LS endocarditis. Anticoagulation therapy should be considered to prevent thromboembolic complications in SLE patients with LS endocarditis.

Quantitative analysis of mitral valve morphology in atrial functional mitral regurgitation using real-time 3-dimensional echocardiography atrial functional mitral regurgitation

Background

Atrial fibrillation (AF) can result in atrial functional mitral regurgitation (MR), but the mechanism remains controversial. Few data about the relationship between the 3-dimensional morphology of the MV and the degree of MR in AF exist.

Methods

Real-time 3-dimensional transesophageal echocardiography (3D-TEE) of the MV was acquired in 168 patients with AF (57.7% persistent AF), including 25 (14.9%) patients with moderate to severe MR (the MR+ group) and 25 patients without AF as controls. The 3-dimensional geometry of the MV apparatus was acquired using dedicated quantification software.

Results

Compared with the group of patients with no or mild MR (the MR- group) and the controls, the MR+ group had a larger left atrium (LA), a more dilated mitral annulus (MA), a reduced annular height to commissural width ratio (AHCWR), indicating flattening of the annular saddle shape, and greater leaflet surfaces and tethering. MR severity was correlated with the MA area (r² = 0.43, P < 0.01) and the annulus circumference (r² = 0.38, P < 0.01). A logistic regression analysis indicated that the MA area (OR: 1.02, 95% CI: 1.01–1.03, P < 0.01), AHCWR (OR: 0.24, 95% CI: 0.14–0.35, P = 0.04) and MV tenting volume (OR: 3.24, 95% CI: 1.16–9.08, P = 0.03) were independent predictors of MR severity in AF patients.

Conclusions

The mechanisms of “atrial functional MR” are complex and include dilation of the MA, flattening of the annular saddle shape and greater leaflet tethering.

Clinical application of cine-MRI in the visual assessment of mitral regurgitation compared to echocardiography and cardiac catheterization

BACKGROUND

Detecting and quantifying the severity of mitral regurgitation is essential for risk stratification and clinical decision-making regarding timing of surgery. Our objective was to assess specific visual parameters by cine-magnetic resonance imaging (MRI) in the determination of the severity of mitral regurgitation and to compare it to previously validated imaging modalities: echocardiography and cardiac ventriculography.

METHODS

The study population consisted of 68 patients who underwent a cardiac MRI followed by an echocardiogram within a median time of 2.0 days and 49 of these patients who had a cardiac catheterization, median time of 2.0 days. The inter-rater agreement statistic (Kappa) was used to evaluate the agreement.

RESULTS

There was moderate agreement between cine MRI and Doppler echocardiography in assessing mitral regurgitation severity, with a kappa value of 0.47, confidence interval (CI) 0.29-0.65. There was also fair agreement between cine MRI and cardiac catheterization with a kappa value of 0.36, CI of 0.17-0.55.

CONCLUSION

Cine MRI offers a reasonable alternative to both Doppler echocardiography and, to a lesser extent, cardiac catheterization for visually assessing the severity of mitral regurgitation with specific visual parameters during routine clinical cardiac MRI.

Proximal Flow Convergence Region as Assessed by Real-time 3-Dimensional Echocardiography: Challenging the Hemispheric Assumption

OBJECTIVE

Traditionally, a hemispheric assumption for the proximal flow convergence region (PFCR) is used when calculating mitral regurgitant (MR) effective orifice area (EROA). However, 2-dimensional (2D) echocardiography limits evaluation of the complete PFCR contour. Real-time 3-dimensional (3D) echocardiography (RT3D) allows direct assessment of the true PFCR contour. We hypothesized that the PFCR contour is not necessarily hemispheric, but rather hemielliptic, and aimed to apply a hemielliptic calculation, based on the 3D contour of the PFCR for more accurate MR quantification.

METHODS

In all, 50 patients with MR underwent RT3D to characterize PFCR contour as hemispheric or hemielliptic. MR EROA by RT3D-derived PFCR was calculated using a hemielliptic formula using 3D data. The 2D EROA was computed using standard hemispheric assumption. EROAs calculated from 2D and RT3D data were compared with quantitative Doppler EROA (mitral inflow--aortic outflow/MR time-velocity integral), used as an independent comparison.

RESULTS

Only 1 of 50 patients (2%) had a hemispheric PFCR contour by RT3D. The remaining had hemielliptic PFCR contours. Compared with Doppler method, 2D echocardiography significantly underestimated EROA (0.34 +/- 0.14 vs 0.48 +/- 0.25 cm(2), P < .001). RT3D EROA was not significantly different from Doppler EROA (0.52 +/- 0.17 vs 0.48 +/- 0.25, P = not significant). Of 33 patients with Doppler EROA greater than 0.3 cm(2) (> or =moderate-severe MR), 45% (15 of 33) were underestimated as having mild to moderate MR by 2D EROA.

CONCLUSIONS

The true PFCR contour as shown by RT3D is generally not hemispheric but hemielliptic, tracking the orifice contour. Based on this 3D shape, a hemielliptic approach can be used for practical clinical application with improved MR quantification.

Impact of Moderate Functional Mitral Insufficiency in Patients Undergoing Surgical Revascularization

BACKGROUND

Mild and moderate functional ischemic mitral insufficiency present at the time of surgical revascularization present clinical uncertainty. It is unclear whether the relatively poor outcomes in this cohort are dependent on valvular function or related to left ventricular dysfunction. The purpose of this study was to examine the early and late outcomes in patients with less-than-severe functional ischemic mitral insufficiency at the time of isolated coronary artery bypass grafting (CABG).

METHODS AND RESULTS

From 1996 through 2004, 2242 consecutive patients undergoing isolated CABG were identified as having none to moderate mitral regurgitation (MR) and no valve leaflet pathology. All of the patients at this single institution routinely had an intraoperative transesophageal echocardiography, prospectively quantified MR, and ejection fraction (EF). The New York State Cardiac Surgery Reporting System infrastructure was used to prospectively collect in-hospital patient variables and outcomes. Social Security Death Benefit Index was used to determine long-term survival. Odds ratio and significance (P value) are presented for each determined risk factor. There were 841 patients (37.5%) with no MR, 1137 (50.7%) with mild MR, and 264 (11.8%) with moderate MR. The patients with moderate MR were more likely to be older, female, and have more renal disease, previous MI, congestive heart failure, previous cardiac surgery, and lower EFs. Hospital mortality was independently and significantly associated with renal disease, decreasing EF, increasing age, previous cardiac operation, and cerebral vascular disease. Multivariable analysis revealed decreased survival with increasing age, previous operation, congestive heart failure, diabetes, nonelective operation, decreasing EF, and the presence of moderate MR (expbeta = 1.49; P=0.007) and mild MR (expbeta = 1.34; P=0.033).

CONCLUSIONS

Independent of ventricular function, mild and moderate functional mitral insufficiency are associated with significantly decreased survival in patients undergoing CABG. Whether correction of moderate functional MR at the time of CABG improves outcome still needs to be determined.

Transthoracic and Transesophageal Echocardiographic Assessment of Mitral Regurgitation Severity: Usefulness of Qualitative and Semiquantitative Techniques

In this report, we review the advantages, limitations, and optimal utilization of various transthoracic and transesophageal echocardiographic (TTE and TEE) methods used for assessing mitral regurgitation (MR) as published in full-length, peer-reviewed articles since the color Doppler era began in 1984. In addition, comparison is made to other imaging modalities including catheter-based, magnetic resonance and surgical assessment of MR. Although left ventricular (LV) angiography has been traditionally used for validation of various TTE methods and is time-honored, its considerable limitations preclude it from being a real "gold standard." Based on the reviewed literature, no clear "gold standard" for the assessment of MR can be identified at present, but newly emerging TTE and TEE techniques, such as three-dimensional color Doppler, may have the potential to overcome some of the limitations of the two-dimensional methods.

Outcome of mild periprosthetic regurgitation detected by intraoperative transesophageal echocardiography

OBJECTIVES

The goal of this study was to determine the outcome of trivial or mild periprosthetic regurgitation (PPR) identified by intraoperative transesophageal echocardiography (TEE).

BACKGROUND

The clinical significance, natural history and correlates of trivial or mild PPR detected early after surgery are unknown.

METHODS

Between 1992 and 1997, 608 consecutive patients underwent isolated aortic valve replacement or mitral valve replacement at Dartmouth-Hitchcock Medical Center. Of these, 113 patients (18.3%) were found to have trivial or mild PPR at surgery by TEE. Follow-up transthoracic echocardiograms (early TTEs) were obtained within six weeks of surgery in 99.0% of patients and late TTEs (mean 2.1 years) in 54.3%. Clinical, intraoperative and outcome variables associated with PPR were identified using t test, chi-square and logistic regression analyses.

RESULTS

By univariate analysis, compared with patients without PPR, patients with PPR were older, of smaller body surface area (BSA), had degenerative valve disease more often and were more likely to receive a bioprosthetic valve. By multivariate analysis, smaller BSA and the use of a bioprosthesis were the strongest predictors of PPR (p < 0.01). At early TTE, PPR was not observed (n = 56) or remained unchanged (n = 44) in all patients. At late TTE, four patients were found to have progression of their PPR. All four patients had bioprosthetic valves. Two of these patients had endocarditis, and one had primary valvular degeneration. The fourth patient had progressive PPR.

CONCLUSIONS

Trivial or mild PPR is a frequent finding on intraoperative TEE. Smaller body size and the use of a bioprosthetic valve are significantly associated with PPR. The clinical significance and natural history of PPR is benign in most cases.

Calculation of mitral regurgitant orifice area with use of a simplified proximal convergence method: initial clinical application

To validate a previously proposed simplified proximal flow convergence method for calculating mitral regurgitant orifice area (ROA), a prospective study was conducted in ambulatory patients and in patients undergoing open heart surgery. Assuming a pressure difference between the left ventricle and left atrium of approximately 100 mm Hg (jet velocity [v(p)] 500 cm/s) and setting the color aliasing velocity (v(a)) to 40 cm/s, we simplified the conventional proximal convergence method formula (ROA = 2pi(r2)v(a)/v(p)) to r2/2, where r is the radius of the proximal convergence isovelocity hemisphere. For 57 ambulatory patients with a wide range of mitral regurgitant severity (1 to 4+), ROA was calculated by the conventional (x) and simplified (y) methods, demonstrating excellent accuracy (r = 0.92; P <.001; DeltaROA [y - x] = 0.004 +/- 0.08 cm2). For 24 intraoperative patients, ROA calculated by the simplified formula (y) correlated well with the pulsed Doppler-thermodilution method (x) (r = 0.84; P <.01; DeltaROA [y - x] = -0.002 +/- 0.08cm2). This simplified proximal convergence formula yields an accurate assessment of ROA for a wide range of regurgitant severity, while the time required for this measurement is shortened by half (1.5 +/- 0.5 minutes versus 3.2 +/- 0.7 minutes). This may increase the frequency of calculating ROA in the clinical laboratory.

Comparison of quantitative and semiquantitative methods for assessing mitral regurgitation by transesophageal echocardiography

Semiquantitative grading of mitral regurgitation (MR) by transesophageal echocardiography (TEE) is widely used for clinical decision making. However, the relation between semiquantitative grading by biplane or multiplane TEE and quantitative measures remains undetermined. Biplane or multiplane TEE was performed in 113 patients in the operating room. MR severity was graded from 1 to 4+ by Doppler color flow mapping. MR was quantified using the thermodilution-Doppler method as mitral regurgitant stroke volume (RSV) derived from the difference between total mitral inflow measured by pulsed Doppler and forward flow measured by thermodilution. Mitral regurgitant orifice area (ROA) was calculated by RSV divided by mitral regurgitant velocity. RSV and ROA were also calculated using the proximal isovelocity surface area method. RSV and ROA significantly correlated with the semiquantitative grading either by TEE or angiogram in a nonlinear fashion, with the best fit being given by an exponential model with correlation coefficients from 0.73 to 0.87 (p <0.001). Substantially increased RSV and ROA were observed in MR grades of > or =3+. In the same grades of 3+ or 4+ MR, the largest RSV was 4 times larger than the smallest (190 to 220 vs 44 to 45 ml), and the largest ROA (1.82 to 2.0 vs 0.26 to 0.27 cm2) was sixfold larger than the smallest. Patients with 2 to 3+ MR had significantly variable RSV and ROA (range 21 to 91 ml and 0.12 to 0.65 cm2, respectively). Color flow mapping by biplane or multiplane TEE or angiography is able to categorize precisely mild (< or =2+) and severe (> or =3+) MR, but cannot accurately determine actual hemodynamic load of MR in more severe degrees of MR.

Echocardiographic Criteria in Selection of Patients for Percutaneous Mitral Commissurotomy

The purpose of this report is to review the role of echocardiography in the selection of patients for percutaneous mitral commissurotomy (PMC). Echocardiography has become the standard for the assessment of the severity of mitral stenosis and of its consequences. PMC is usually performed only in patients with a valve area of < 1.5 cm(2), whereas pulmonary hypertension or spontaneous echo contrast in the left atrium may lead to intervention in patients with few symptoms. The next step of the echocardiographic evaluation is to eliminate contraindications: left atrial thrombosis (by the systematic performance of a transesophageal examination before PMC), mitral regurgitation >/= 2/4, severe aortic valve disease, mixed tricuspid valve disease, and massive or bicommissural calcification. Finally, echocardiography allows the classification of patients into different anatomic groups for prognostic consideration. There is controversy regarding the best echo score system in the prediction of the results of PMC. Scores using a global evaluation of the valve anatomy are the most widely used, whereas more recently, scores taking into account the uneven distribution of the disease have had promising preliminary results. Overall, echo scores are useful criteria for selecting candidates for PMC, but they should be considered together with the other clinical and procedural variables. Thus, echocardiography has an important role in the selection of patients for PMC, as well as for the guidance of the procedure, the evaluation of the results, and surveillance.

Three-dimensional color Doppler: a clinical study in patients with mitral regurgitation

OBJECTIVES

The purpose of this study was to assess the clinical feasibility of three-dimensional (3D) reconstruction of color Doppler signals in patients with mitral regurgitation.

BACKGROUND

Two-dimensional (2D) color Doppler has limited value in visualizing and quantifying asymmetric mitral regurgitation. Clinical studies on 3D reconstruction of Doppler signals in original color coding have not yet been performed in patients. We have developed a new procedure for 3D reconstruction of color Doppler.

METHODS

We studied 58 patients by transesophageal 3D echocardiography. The jet area was assessed by planimetry and the jet volumes by 3D Doppler. The regurgitant fractions, the volumes, and the angiographic degree of mitral regurgitation were assessed in 28 patients with central jets and compared with those of 30 patients with eccentric jets.

RESULTS

In all patients, jet areas and jet volumes significantly correlated with the angiographic grading (r = 0.73 and r = 0.90), the regurgitant fraction (r = 0.68 and r = 0.80) and the regurgitant volume (r = 0.66 and r = 0.90). In patients with central jets, significant correlations were found between jet area and angiography (r = 0.86), regurgitant fraction (r = 0.64) and regurgitant volume (r = 0.78). No significant correlations were found between jet area and angiography (r = 0.53), regurgitant fraction (r = 0.52) and regurgitant volume (r = 0.53) in the group of patients with eccentric jets. In contrast, jet volumes significantly correlated with angiography (r = 0.90), regurgitant fraction (r = 0.75) and regurgitant volume (r = 0.88) in the group of patients with eccentric jets.

CONCLUSIONS

Three-dimensional Doppler revealed new images of the complex jet geometry. In addition, jet volumes, assessed by an automated voxel count, independent of manual planimetry or subjective estimation, showed that 3D Doppler is also capable of quantifying asymmetric jets.

Usefulness of intraoperative transesophageal echocardiography in predicting the degree of mitral regurgitation secondary to atrioventricular defect in children

The objectives of this study were to determine the validity of the grade of mitral regurgitation (MR) as imaged by intraoperative transesophageal echocardiography (TEE) in predicting the grade of MR at follow-up. Intraoperative TEE and corresponding follow-up transthoracic studies were retrospectively reviewed and the regurgitant jet area to left atrial area ratio was used to quantify the MR. Patient records were reviewed to identify factors contributing to the development of a certain grade of MR. Intraoperative TEE was useful in detecting severe MR that required further repair at the same time. However, discrepancy in the grade of MR at follow-up was noted in 47% of patients (21 of 47) and unchanged grade of MR was found only in 53% of patients (26 of 47). Blood pressures were significantly lower and heart rates higher intraoperatively. Initial preoperative grade of MR and type of atrioventricular canal defect did not predispose for a particular grade of MR at follow-up. The grade of MR by intraoperative TEE does not predict the grade of MR at follow-up as imaged by transthoracic echocardiography.

Three-dimensional color Doppler: a new approach for quantitative assessment of mitral regurgitant jets

Color Doppler echocardiography does not provide adequate information about the severity of mitral regurgitation in patients with eccentric mitral regurgitation. We have developed a new procedure for 3-dimensional (3D) color Doppler reconstruction and for segmentation of regurgitant jets. The volume of regurgitant jets was compared with jet area in 63 patients with mitral regurgitation. Mitral regurgitation was assessed by angiography, regurgitant fraction and volume by pulsed Doppler, JA by planimetry, and JV by 3-dimensional Doppler. Twenty-eight patients with central jets were compared with 35 patients with eccentric jets. In the patients with eccentric jets, JV showed significant correlations with regurgitant volume (r = 0.90; P <.01) and regurgitant fraction (r = 0.76; P < .01) and was able to separate groups with different degrees of mitral regurgitation (P <.01). Three-dimensional Doppler revealed origin, direction, and spatial spreading of complex jet geometry. JV, a new parameter of mitral regurgitation, was also capable of quantifying asymmetrical jets.

An unusual tethering of the bridging leaflets in atrioventricular septal defect producing a communication from left atrium to right ventricle

We describe a 39-year-old woman who was diagnosed as having an unusual atrioventricular septal defect with a communication from left atrium to right ventricle. A common atrioventricular junction, with partially separated right and left atrioventricular orifices, was found at transoesophageal ultrasonic examination. Both bridging leaflets were attached to the underside of the atrial septum, which was grossly malaligned relative to the ventricular septum. The shunt was exclusively from left atrium to right ventricle because of the overriding of the left atrioventricular valve, with the left component of the inferior bridging leaflet firmly fused to the ventricular septal crest.

Aortic root disease and valve disease associated with ankylosing spondylitis

OBJECTIVES

This study sought to determine the prevalence, characteristics, relation to clinical features and evolution of aortic root disease and valve disease associated with ankylosing spondylitis (AKS).

BACKGROUND

Aortic root disease and valve disease are common in patients with AKS, but their clinical and prognostic implications have not been well defined.

METHODS

Forty-four outpatients with AKS and 30 age- and gender-matched healthy volunteers underwent initial transesophageal echocardiography and rheumatologic evaluations. Twenty-five patients underwent clinical and echocardiographic follow-up 39+/-10 months later.

RESULTS

Aortic root disease and valve disease were common in patients (82%) as compared with controls (27%; p < 0.001). Aortic root thickening, increased stiffness and dilatation were seen in 61%, 61% and 25% of patients, respectively. Valve thickening (41% for the aortic and 34% for the mitral valve) manifested predominantly (74%) as nodularities of the aortic cusps and basal thickening of the anterior mitral leaflet, forming the characteristic subaortic bump. Valve regurgitation was seen in almost half of patients, and 40% had moderate lesions. Except for the duration of AKS, aortic root disease and valve disease were unrelated to the activity, severity or therapy of AKS. During follow-up of 25 patients, in up to 24% new aortic root or valve abnormalities developed, in 12% existing valve regurgitation worsened significantly and in 20% abnormalities resolved. Twenty percent of patients developed heart failure, underwent valve replacement, had a stroke or died, as compared with 3% of control subjects.

CONCLUSIONS

Aortic root disease and valve disease are common in patients with AKS, are unrelated to clinical features of AKS, can resolve or progress over time and are associated with clinically important cardiovascular morbidity.

Quantification of mitral regurgitation by automated cardiac output measurement: experimental and clinical validation

OBJECTIVES

To develop and validate an automated noninvasive method to quantify mitral regurgitation.

BACKGROUND

Automated cardiac output measurement (ACM), which integrates digital color Doppler velocities in space and in time, has been validated for the left ventricular (LV) outflow tract but has not been tested for the LV inflow tract or to assess mitral regurgitation (MR).

METHODS

First, to validate ACM against a gold standard (ultrasonic flow meter), 8 dogs were studied at 40 different stages of cardiac output (CO). Second, to compare ACM to the LV outflow (ACMa) and inflow (ACMm) tracts, 50 normal volunteers without MR or aortic regurgitation (44+/-5 years, 31 male) were studied. Third, to compare ACM with the standard pulsed Doppler-two-dimensional echocardiographic (PD-2D) method for quantification of MR, 51 patients (61+/-14 years, 30 male) with MR were studied.

RESULTS

In the canine studies, CO by ACM (1.32+/-0.3 liter/min, y) and flow meter (1.35+/-0.3 liter/min, x) showed good correlation (r=0.95, y=0.89x+0.11) and agreement (deltaCO(y-x)=0.03+/-0.08 [mean+/-SD] liter/min). In the normal subjects, CO measured by ACMm agreed with CO by ACMa (r=0.90, p < 0.0001, deltaCO=-0.09+/-0.42 liter/min), PD (r=0.87, p < 0.0001, deltaCO=0.12+/-0.49 liter/min) and 2D (r=0.84, p < 0.0001, deltaCO=-0.16+/-0.48 liter/min). In the patients, mitral regurgitant volume (MRV) by ACMm-ACMa agreed with PD-2D (r= 0.88, y=0.88x+6.6, p < 0.0001, deltaMRV=2.68+/-9.7 ml).

CONCLUSIONS

We determined that ACM is a feasible new method for quantifying LV outflow and inflow volume to measure MRV and that ACM automatically performs calculations that are equivalent to more time-consuming Doppler and 2D measurements. Additionally, ACM should improve MR quantification in routine clinical practice.

The effect of exercise on ischemic mitral regurgitation

This study investigated the effect of dynamic exercise on mitral regurgitation (MR) as assessed by color flow Doppler imaging and tested the hypothesis that MR increases in patients with left ventricular (LV) function worsening during exercise. We studied 513 patients (390 men, 123 women:mean age [+/-1 SD] 58+/-11 years) referred for treadmill exercise echocardiography (EE) to evaluate known or suspected coronary artery disease. Normal EE was seen in 182 (36%), necrosis in 131 (25%), and ischemic response (with or without necrosis) in 200 (39%). MR assessment was performed at rest and immediately postexercise, on the basis of the mosaic area. At rest, mild MR (<3 cm2) was seen in 138; moderate (3 to 6 cm2) was seen in 21; and severe (>6 cm2) was seen in 5. Forty-two patients developed new, mild (n=35), moderate (n=6), or severe (n=1) MR during exercise. Patients were assigned to three groups: group 1--new or increased MR from rest to exercise (n=70); group 2--MR at rest unchanged or decreased (n=136); and group 3--no MR at rest and exercise (n=307). At rest, LV ejection fraction (EF) and wall motion score index (WMSI) were similar in group 1 and group 2 but improved in group 3 (EF: group 1, 51+/-11%; group 2, 53+/-10%; group 3, 56+/-8%, p<0.001 vs group 1 and group 2. WMSI: group 1, 1.3+/-0.3; group 2, 1.3+/-0.4; group 3, 1.1+/-0.2, p<0.01 vs group 1, p<0.001 vs group 2). At exercise, EF and WMSI were impaired in group 1 (EF: group 1, 52+/-14%; group 2, 58+/-15%; group 3, 64+/-11%, p<0.001 vs group 1 and group 2; p<0.05 between group 1 and group 2. WMSI: group 1, 1.5+/-0.4; group 2, 1.4+/-0.4; group 3, 1.2+/-0.3, p<0.001 vs group 1 and group 2, p<0.05 between group 1 and group 2). An ischemic response was common in group 1 (67% vs 35% in group 2 and 34% in group 3, p<0.001 between group 1 and group 3 and between group 1 and group 2). Accordingly, in group 1 patients, exercise time was diminished (7.3+/-2.7 vs 8.4+/-2.7 in group 2 and 9.3+/-2.4 in group 3, p<0.01, between group 1 and group 2, p<0.001 between group 1 and group 3, p<0.001 between group 2 and group 3) and the number of severely narrowed coronary vessels greater (2.4+/-0.9 vs 1.7+/-1.0 in group 2 and 1.7+/-1.0 in group 3). In conclusion, MR does not increase in most patients submitted to dynamic exercise echocardiography. However, if MR develops, severe LV function worsening should be suspected.

Clinical and morphological characteristics in Streptococcus bovis endocarditis: a comparison with other causative microorganisms in 177 cases

AIM

To compare the clinical and morphological characteristics of patients with Streptococcus bovis endocarditis with those of patients with endocarditis caused by other microorganisms.

METHODS

177 consecutive patients (Streptococcus bovis, 22; other streptococci, 94; staphylococci, 44; other, 17) with definite infective endocarditis according to the Duke criteria were included. All patients underwent transthoracic and transoesophageal echocardiography. In 88 patients, findings from surgery/necropsy were obtained.

RESULTS

S bovis endocarditis was associated with older patients, with a higher mortality (p = 0.04), and with a higher rate of cardiac surgery (p < 0.001) than other microorganisms, although embolic events were observed less often (p = 0.02). Pathological gastrointestinal lesions were detected in 45% of the patients. Multiple valves were affected in 68% of the patients with S bovis endocarditis and in 20% of those with other organisms (p < 0.001). Moderate or severe regurgitation occurred more often in S bovis endocarditis than with other microorganisms (p = 0.05). When surgery or necropsy was performed, infectious myocardial infiltration of the left ventricle was confirmed histopathologically in 36% of the patients with S bovis endocarditis and in 10% of those with other organisms (p = 0.002).

CONCLUSIONS

S bovis endocarditis is a severe illness because of the more common involvement of multiple valves, and of the frequent occurrence of haemodynamically relevant valvar regurgitation and infectious myocardial infiltration.

Pulmonary venous blood flow pattern in patients with univentricular hearts following total cavo-pulmonary connection

The objective of the study was evaluation of the pulmonary venous blood flow (PVF) pattern and the influence of ventricular function and atrioventricular valve regurgitation on this flow in patients with univentricular hearts post total cavo-pulmonary connection (TCPC). Transthoracic or transoesophageal echocardiographic studies were performed in 24 children with normal hearts (group A) and in 24 patients with univentricular hearts (group B). Ventricular function and atrioventricular valve regurgitation was semiquantitatively assessed. Systolic/diastolic maximal velocities and velocity time integrals (VTI) were measured from PVF tracings. Ejection fraction was measured by radionuclide angiography in 11 patients. Twelve patients underwent heart catheterization and angiography. In group B the PVF showed a biphasic flow velocity curve. The systolic integrals were smaller and the diastolic integrals were larger than in group A (6.4 vs. 13.0 cm, P = 0.0001, and 13.9 vs. 10.0 cm, P = 0.005). The pulmonary venous systolic flow fraction in 13 patients with an open fenestration and/or atrioventricular valve regurgitation grade 2-3 was significantly lower than in those 11 patients without fenestration and none/small regurgitation (0.19 vs. 0.40, P = 0.05). In conclusion, the PVF pattern in children with univentricular hearts pallitated with TCPC is similar to the PVF pattern found in individuals with biventricular hearts showing a biphasic flow velocity curve despite the absence of pulsatile pulmonary artery flow. The PVF in patients with TCPC-palliated univentricular hearts is influenced by atrioventricular valve regurgitation and fenestration flow.

Values for Mitral Valve Annulus Dimensions in Normals and Patients with Mitral Regurgitation

OBJECTIVES: The present study was designed to investigate the dimensions of mitral valve annulus in the presence of mitral regurgitation. METHOD: Fifty-four patients were examined. On transthoracic echocardiographic images, we performed linear measurements in the parasternal plane in order to define the size of the left ventricle, left atrium, and mitral valve annulus. We compared these findings with those obtained in 16 control subjects. RESULTS: Twenty-one patients with mild or moderate mitral regurgitation demonstrated no significant change of the mitral valve annulus compared with the control group (P > 0.05). Seventeen patients with severe mitral regurgitation (grade of 4) had a significant increase of the dimensions of the mitral valve annulus, left ventricle, and left atrium (P < 0.05). The etiology of mitral regurgitation was degenerative in 32 patients, rheumatic in 2 patients, and mitral valve prolapse in 4 patients. All patients had normal left ventricular systolic function. Thirty-one patients were in normal sinus rhythm, and seven were in atrial fibrillation. CONCLUSIONS: The measurement of the diameter of the mitral valve annulus is feasible with transthoracic echocardiography. In addition to the evaluation of mitral valve leaflets and subvalvular apparatus, the measurement of the mitral valve annulus is important in the evaluation of mitral regurgitation, as its enlargement is indicative for severe mitral regurgitation.

Left ventricular diastolic filling with an implantable ventricular assist device: beat to beat variability with overall improvement

OBJECTIVES

We studied the effects of left ventricular (LV) unloading by an implantable ventricular assist device on LV diastolic filling.

BACKGROUND

Although many investigators have reported reliable systemic and peripheral circulatory support with implantable LV assist devices, little is known about their effect on cardiac performance.

METHODS

Peak velocities of early diastolic filling, late diastolic filling, late to early filling ratio, deceleration time of early filling, diastolic filling period and atrial filling fraction were measured by intraoperative transesophageal Doppler echocardiography before and after insertion of an LV assist device in eight patients. A numerical model was developed to simulate this situation.

RESULTS

Before device insertion, all patients showed either a restrictive or a monophasic transmitral flow pattern. After device insertion, transmitral flow showed rapid beat to beat variation in each patient, from abnormal relaxation to restrictive patterns. However, when the average values obtained from 10 consecutive beats were considered, overall filling was significantly normalized from baseline, with early filling velocity falling from 87 +/- 31 to 64 +/- 26 cm/s (p < 0.01) and late filling velocity rising from 8 +/- 11 to 32 +/- 23 cm/s (p < 0.05), resulting in an increase in the late to early filling ratio from 0.13 +/- 0.18 to 0.59 +/- 0.38 (p < 0.01) and a rise in the atrial filling fraction from 8 +/- 10% to 26 +/- 17% (p < 0.01). The deceleration time (from 112 +/- 40 to 160 +/- 44 ms, p < 0.05) and the filling period corrected by the RR interval (from 39 +/- 8% to 54 +/- 10%, p < 0.005) were also significantly prolonged. In the computer model, asynchronous LV assistance produced significant beat to beat variation in filling indexes, but overall a normalization of deceleration time as well as other variables.

CONCLUSIONS

With LV assistance, transmitral flow showed rapidly varying patterns beat by beat in each patient, but overall diastolic filling tended to normalize with an increase of atrial contribution to the filling. Because of the variable nature of the transmitral flow pattern with the assist device, the timing of the device cycle must be considered when inferring diastolic function from transmitral flow pattern.

Valve excrescences: prevalence, evolution and risk for cardioembolism

OBJECTIVES

We sought to determine prospectively the prevalence, evolution and embolic risk of valve excrescences in normal subjects and patients with and without suspected cardioembolism.

BACKGROUND

Valve excrescences detected by transesophageal echocardiography (TEE) have been considered a cardioembolic substrate in selected patients.

METHODS

Ninety healthy volunteers (Group I) and 88 patients without suspected cardioembolism and a normal TEE (Group II) were studied and followed up clinically for 58 +/- 21 and 48 +/- 20 months, respectively. To assess the evolution of valve excrescences, 45 of these subjects underwent repeat TEE at 31 +/- 13 months. The findings in Groups I and II were compared with those of Group III--49 patients referred for TEE for suspected cardioembolism.

RESULTS

Valve excrescences were detected in 34 subjects (38%) in Group I and in 41 patients (47%) in Group II. In Group III, 20 patients (41%) had excrescences, but 85% of them had other potential cardiac or vascular sources of embolism. In all groups, mitral valve excrescences were predominant (68% to 76%), followed by aortic (38% to 50%) and right-sided valves (<10%). Excrescences were equally frequent in men and women and between all age groups studied. During follow-up in Groups I and II, excrescences persisted unchanged, and 1 (1.4%) of 74 patients with and 2 (2%) of 99 subjects without excrescences had cerebral ischemic events (80% power to detect a clinically meaningful difference of 4%).

CONCLUSIONS

Valve excrescences are common on the left-sided heart valves of normal subjects and patients regardless of gender and age; they persist unchanged over time and do not appear to be a primary source of cardioembolism.

Determinants of functional capacity in chronic mitral regurgitation unassociated with coronary artery disease or left ventricular dysfunction

Impaired functional capacity is common in patients with mitral regurgitation (MR), but the determinants of functional capacity in patients with normal left ventricular (LV) function are unclear. Forty patients with chronic, isolated, nonrheumatic MR with no coronary artery disease underwent exercise echocardiography with continuous expired gas analysis. Cardiac output and regurgitant stroke volume were measured at rest and immediately after exercise by pulsed-wave Doppler echocardiography. For controls, 17 healthy volunteers without MR were also studied. Patients achieved a significantly lower VO2max compared with controls (25.6 +/- 7.7 vs 31.7 +/- 7.7 ml/kg/min, p = 0.008). VO2max showed better correlations with exercise cardiac output than with cardiac output at rest in both patients and controls. Multiple linear regression identified exercise cardiac output (partial r = 0.65), patient age (partial r = -0.56), and gender as independent determinants of VO2max (multiple R = 0.85, p <0.001). Cardiac output at rest, LV ejection fraction, regurgitant stroke volume, and fraction were not significant determinants. With exercise, the regurgitant stroke volume increased in 13 patients and decreased in 27 patients. The former 13 patients had a significantly lower exercise cardiac output (7.4 +/- 2.5 vs 9.4 +/- 2.6 L/min, p = 0.026). Patients who stopped exercise due to dyspnea (n = 7) had a significantly lower exercise cardiac output and VO2max compared with those who stopped due to fatigue (n = 33), with no differences in resting or exercise regurgitant volume. Patients with an increase in LV end-systolic volume with exercise (n = 8) also had a significantly lower exercise cardiac output (6.9 +/- 1.9 vs 9.2 +/- 2.7 L/min, p = 0.037) and showed a trend toward a lower VO2max (21 +/- 7.5 vs 26 +/- 6.4 ml/kg/min, p = 0.07). In patients with chronic MR, exercise cardiac output is the major determinant of VO2max. Regurgitant volume and fraction are not related to functional capacity. Limitations in functional capacity in these patients may be more related to a diminished cardiac reserve than to a large regurgitant volume.

Assessment of mitral regurgitation severity by Doppler color flow mapping of the vena contracta

BACKGROUND

Although Doppler color flow mapping is widely used to assess the severity of mitral regurgitation (MR), a simple, accurate, and quantitative marker of MR by color flow mapping remains elusive. We hypothesized that vena contracta width by color flow mapping would accurately predict the severity of MR.

METHODS AND RESULTS

We studied 80 patients with MR. Vena contracta width was measured in multiple views with zoom mode and nonstandard angulation to optimize its visualization. Flow volumes across the left ventricular outflow tract and mitral annulus were calculated by pulsed-Doppler technique to determine regurgitant volume. Effective regurgitant orifice area was calculated by dividing the regurgitant volume by the continuous-wave Doppler velocity-time integral of the MR jet. The cause of MR was ischemia in 24, dilated cardiomyopathy in 34 mitral valve prolapse in 12, endocarditis in 2, rheumatic disease in 2, mitral annular calcification in 1, and uncertain in 5. Regurgitant volumes ranged from 2 to 191 mL. Regurgitant orifice area ranged from 0.01 to 1.47 cm2. Single-plane vena contracta width from the parasternal long-axis view correlated well with regurgitant volume (r = .85, SEE = 20 mL) and regurgitant orifice area (r = .86, SEE = 0.15 cm2). Biplane vena contracta width from apical views correlated well with regurgitant volume (r = .85, SEE = 19 mL) and regurgitant orifice area (r = .88, SEE = 0.14 cm2). A biplane vena contracta width > or = 0.5 cm was always associated with a regurgitant volume > 60 mL and a regurgitant orifice area > 0.4 cm2. A biplane vena contracta width < or = 0.3 cm predicted a regurgitant volume < 60 mL and a regurgitant orifice area < 0.4 cm2 in 24 of 29 patients. No other parameter, including jet area, left atrial size, pulmonary flow reversal, or semiquantitative MR grade, correlated significantly with regurgitant volume or regurgitant orifice area in a multivariate analysis.

CONCLUSIONS

Our results demonstrate that careful color flow mapping of the vena contracta of the MR jet provides a simple quantitative assessment of MR that correlates well with quantitative Doppler techniques.

Quantitative Assessment of Simulated Regurgitant Flow Using Direct Digital Acquisition of Doppler Color Flow Images

Analysis of jet momentum and proximal isovelocity surface area (PISA) have been shown to be accurate in quantitating regurgitant flow for axisymmetric free jets. However, eccentric jets directed against chamber walls are often encountered in clinical practice and could confound the assessment of regurgitant flow. Thus, we used direct digital color flow mapping to calculate flow by the momentum method and PISA in a flow model. Steady flow jets were driven through a 2-mm round orifice at flow rates of 3, 6, 9, 12, 15, and 20 mL/sec. Jets were directed centrally and against the lateral wall of a 150 mL chamber. The raw data from a 3.25/2.5 MHz transducer (Vingmed CFM 750) was digitally transferred to a Macintosh IIci computer for analysis of the velocities comprising the jets. By linear regression, PISA was accurate in assessing flow for both free jets and wall jets (r(2) = 0.98) with regression lines approximating unity. The momentum method was highly accurate for free jets (r(2) = 0.98) but systematically underestimated flow for wall jets (r(2) = 0.70, y = 0.21x + 0.88). Thus, analysis of simulated regurgitant flow using digital display of velocities encoded in the color flow jet is accurate for free jets by both the PISA and momentum techniques. In wall jets, the momentum technique underestimates flow because the requirement for jet axisymmetry is not met.

Usefulness of multiplane transesophageal echocardiography to improve the assessment of severity of mitral regurgitation

This study was designed to examine the accuracy of multiplane transesophageal echocardiography (TEE) color Doppler measurements in comparison to monoplane or biplane measurements in estimating the severity of mitral regurgitation (MR). Multiplane TEE potentially increases diagnostic accuracy of transesophageal examinations; it is unknown if multiplane is more accurate in assessing the severity of MR than monoplane or biplane TEE. Left ventricular cineangiograms of 91 patients with MR (40 no or mild, 30 moderate, and 21 severe) were compared with systolic pulmonary venous flow reversal and transesophageal color Doppler measurements: jet area and length in the transverse and longitudinal plane, maximal and average of those 2 planes (biplane), and maximal and average of 11 different planes (multiplane). Flow reversal (16 patients) identified severe MR with a specificity of 96% and a sensitivity of 62%; these were 96% and only 10% to 43%, respectively, for color Doppler measurements. In the absence of flow reversal, multiplane maximal jet area predicted severe MR with a sensitivity of 88% and a specificity of 75%, which were 85% and 76%, respectively, for no or mild MR; this did not differ significantly from results obtained by monoplane or biplane measurements. Color Doppler measurements of eccentric jets were not reliable for identification of severe MR. Systolic pulmonary venous flow reversal identifies 2 of 3 patients with severe MR with a high accuracy. In patients without flow reversal, multiplane color Doppler TEE is very capable of assessing MR severity, but biplane and monoplane TEE are equally accurate.

An echocardiographic study of valvular heart disease associated with systemic lupus erythematosus

BACKGROUND

Valvular heart disease is the most important cardiac manifestation of systemic lupus erythematosus. We performed a study to determine the relation of valvular disease to other clinical features of lupus, whether or not the valve disease progresses, and the associated morbidity and mortality.

METHODS

We performed transesophageal echocardiography and rheumatologic evaluations in 69 patients with systemic lupus erythematosus. The echocardiographic findings were compared with those in 56 healthy volunteers. Fifty-eight patients (84 percent) had second evaluations a mean (+/-SD) period of 29 +/- 13 months later. The patients and controls were followed for 57 months.

RESULTS

Valvular abnormalities were common on the initial and the follow-up echocardiograms (in 61 and 53 percent of the patients, respectively). Valvular thickening was the predominant finding initially and on follow-up (in 51 and 52 percent of the patients, respectively), followed by vegetations (in 43 and 34 percent), valvular regurgitation (in 25 and 28 percent), and stenosis (in 4 and 3 percent). Valvular abnormalities frequently resolved, appeared for the first time, or persisted but changed in appearance or size between the two studies. Mild or moderate valvular regurgitation did not progress to become severe, and new stenoses did not develop. Neither the presence of valvular disease nor changes in the echocardiographic findings were temporally related to the duration, activity, or severity of lupus or to its treatment. The combined incidence of stroke, peripheral embolism, heart failure, infective endocarditis, and the need for valve replacement was 22 percent in the patients with valvular disease, but only 8 percent in those without it. A total of seven patients died during follow-up, in most cases as a result of valvular disease. Valvular abnormalities and complications were uncommon in the controls (occurring in 9 and 2 percent, respectively).

CONCLUSIONS

Valvular heart disease is common in patients with systemic lupus erythematosus, frequently changes over time, appears to be temporally unrelated to other clinical features of lupus, and is associated with substantial morbidity and mortality.

Biplane transesophageal color-flow Doppler imaging in assessing severity of mitral regurgitation: influence of hemodynamic circumstances and mechanism of regurgitation

OBJECTIVE

To determine the value of biplane transesophageal echocardiography in the assessment of severity of mitral regurgitation compared with left ventricular angiography.

DESIGN

Prospective study of consecutive patients.

SETTING

Two university hospitals, one community hospital.

PARTICIPANTS

Thirty-seven patients with angiographically proven mitral regurgitation.

INTERVENTION

Transthoracic and biplane transesophageal echocardiography. In 19 patients, transesophageal echocardiography was performed during general anesthesia.

MEASUREMENTS AND MAIN RESULTS

The largest mitral regurgitation jet area and longest jet as obtained with Doppler color-flow mapping from transthoracic and biplane transesophageal echocardiography and pulsed-Doppler pulmonary venous flow characteristics. Sensitivity and 100-minus-specificity were plotted to constitute receiver operating characteristics (ROC) curves. Areas under ROC curve for transverse, longitudinal, and biplane jet area were 0.77, 0.75, and 0.81, and for jet length, 0.82, 0.84, and 0.88, respectively; this was for biplane jet area in conscious patients; 0.99 compared with 0.72 in anesthetized patients (p < 0.05).

CONCLUSIONS

Biplane measurements identified severe mitral regurgitation slightly more reliably than the transverse or longitudinal measurements alone. In conscious patients, jet area was an excellent test for estimating severity of mitral regurgitation. In anesthetized patients, a combination of biplane jet area and length and of systolic pulmonary venous flow reversal accurately predicted angiographic severity of mitral regurgitation. In anesthetized patients, the optimal cut-off value for jet area to distinguish between moderate and severe mitral regurgitation was lower than in conscious patients. In the total population, regardless of hemodynamic and technical variations, a combination of biplane jet area and length and of systolic pulmonary venous flow reversal accurately predicted the severity of mitral regurgitation.

Transesophageal echocardiography

This article presents an overview of the benefits and efficacy of transesophageal echocardiography (TEE) in the critically ill patient. The echocardiographic evaluation of ventricular function both regional and global, is discussed with special emphasis on ischemic heart disease; assessment of preload, interrogation of valvular heart disease (prosthetic and native) and its complications; endocarditis and its complications; intracardiac and extracardiac masses, including pulmonary embolism; aortic diseases (e.g., aneurysan, dissection, and traumatic tears); evaluation of patent foramen ovale and its association with central and peripheral embolic events; advancements in computer technology; and finally, the effect of TEE on critical care.

Value of systolic pulmonary venous flow reversal and color Doppler jet measurements assessed with transesophageal echocardiography in recognizing severe pure mitral regurgitation

We evaluated the value of color and pulsed Doppler transesophageal echocardiographic parameters and of V waves in estimating the severity of mitral regurgitation (MR) in 62 consecutive patients (38 men and 24 women, aged 39 to 80 years) with angiographically proven chronic pure MR (15 grade I/II, 47 grade III/IV). Twenty patients were examined before cardiac surgery under general anesthesia. Sensitivity, specificity, and positive and negative predictive values of systolic pulmonary venous flow reversal for the presence of grade III/IV MR were 87%, 93%, 98%, and 64%, respectively, these were for jet areas > or = 8.0 cm2--66%, 100%, 100%, and 48%, for jet lengths > or = 50 mm--70%, 87%, 94%, and 48%, for enlarged V waves--86%, 38%, 83%, and 43%, and for either flow reversal or a jet area > or = 8.0 cm2--96%, 93%, 98%, and 88%. We conclude that a combination of measurements improved the negative predictive value considerably, which is of importance in a population with a high pretest probability of severe MR. Enlarged V waves are not reliable in predicting severe MR. The optimal cutoff value for jet area and jet length was lower in anesthesized patients than in conscious patients; in anesthesized patients, sensitivity, specificity, and positive and negative predictive values of jet area > or = 5.0 CM2 for grade III/IV MR were 67%, 100%, 100%, and 50%, respectively; these were 87%, 100%, 100%, and 71% for flow reversal. Because the results of mitral repair are often evaluated with transesophageal echocardiography during surgery, our findings have clinical implications for evaluation of severe MR in anesthesized patients: pulmonary venous flow direction is the first-choice measure; jet area can be used when a low cutoff point is chosen.

In vitro flow mapping of regurgitant jets. Systematic description of free jet with laser Doppler velocimetry

BACKGROUND

Color Doppler and magnetic resonance imaging give pictures of abnormal jets within which the respective contribution of fluid mechanics and image artifacts are difficult to establish because of current technical limitations of these modalities. We conducted the present study to provide numerical descriptions of the velocity fields within regurgitant free jets.

METHODS AND RESULTS

Laser Doppler measurements were collected in rigid models with pulsatile flow conditions, giving several series of two-dimensional flow images. The data were studied with the use of two-dimensional or M-mode flow images as well as regular plots. Numerical descriptions validated in steady flow conditions were tested at the various times of the cycle. In these free jets, the momentum was conserved throughout the cycle. The transverse velocity profiles were approximately similar. A central laminar core was found at peak ejection and during the deceleration. Its length (l = 4.08 d-0.036 mm, r = .99) and its diameter (d) were proportional to the orifice diameter. At peak ejection, the velocity decay was hyperbolic, and the transverse velocity profiles were clearly gaussian. The different relations that were tested could be combined in a single formula describing the velocity field: V(x,y,t peak) = V(O,O,t peak).4.(d/x).10(-45(y/x)2) (r = .92).

CONCLUSIONS

These in vitro measurements demonstrated the presence of a central laminar core and similar transverse velocity profiles in free turbulent jets. This allowed us to validate a series of numerical relations that can be combined to describe the velocity fields at peak ejection. On the other hand, further studies are needed to describe the various singularities often encountered in pathology.

Value of the cardiovascular physical examination for detecting valvular heart disease in asymptomatic subjects

To determine the accuracy of the cardiovascular physical examination for the diagnosis of asymptomatic valvular heart disease (VHD), we prospectively studied 143 subjects, 68 apparent normal subjects and 75 patients with diseases known to produce VHD. All subjects underwent a complete physical examination with dynamic cardiac auscultation by a physician blinded to clinical data and compared with the results of transesophageal color Doppler echocardiography (TEE). By TEE, 33 subjects (23%), and by physical examination, 25 subjects (17%) had at least 1 form of VHD. Despite a high frequency of mild valve abnormalities and a 31% prevalence of functional murmurs, the physical examination showed a sensitivity of 70%, a specificity of 98% (confidence interval = 0.51 to 0.84, and 0.94 to 0.99, respectively), and a positive and negative predictive value of 92% for the diagnosis of VHD. Only 2 of the 10 patients with VHD by TEE, but not by physical examination, had clinically important VHD. We conclude that the physical examination is a sensitive and highly specific method of screening for VHD in subjects without cardiac symptoms. Therefore, its use should be encouraged rather than the routine application of echocardiography.

Transesophageal echocardiography in myocardial revascularization: II. Influence on intraoperative decision making

This study was conducted to determine how transesophageal echocardiography (TEE) guides intraoperative decision making during myocardial revascularization. Although its usefulness in influencing clinical decision making during cardiac valvular surgery is well documented, the clinical utility of TEE in patients undergoing myocardial revascularization is less clear. We studied the performance of five community-based, full-time cardiac anesthesiologists during 75 surgical procedures. All patients were monitored with radial artery and pulmonary artery catheters as well as biplane TEE. Immediately after each clinical intervention, the anesthesiologist was asked to determine how real-time TEE influenced the therapy, which single monitor was most influential, and why each therapy was initiated. Of the 584 interventions, TEE was the single most important guiding factor in 98 instances (17%). Interventions involving fluid administration contributed to 277 of 584 (47%) of the total clinical decisions. TEE was the most important monitor influencing fluid administration in 82 of 277 instances (30%), versus the pulmonary artery catheter in 20 of 277 instances (7%). TEE was the single most important monitor in guiding other therapies as follows: antiischemic therapy, 8 of 38 = 21%; vasopressor or inotrope administration, 4 of 115 = 3%; vasodilator therapy, 1 of 38 = 3%; antiarrhythmic medications, 0 of 16 = 0%; and depth of anesthesia, 1 of 72 = 1%. In 2 of 75 patients (3%), critical surgical interventions were made solely on the basis of TEE. Also, TEE was found to act in concert with other monitors in 254 of 584 interventions (43%). TEE is often influential in guiding decision making in myocardial revascularization when incorporated as a routine monitor in the intraoperative setting. Information from TEE has been most commonly used to guide the management of fluid administration and institution of antiischemic therapy. In a small subset of patients, TEE appears to be useful in guiding critical surgical interventions.

Transesophageal echocardiography in myocardial revascularization: I. Accuracy of intraoperative real-time interpretation

Transesophageal echocardiography (TEE) is increasingly used intraoperatively as a monitor of ventricular function and volume. Despite its increasing use, whether data from TEE monitoring can be interpreted accurately on-line in real-time is unknown. We studied the performance of five community-based, full-time cardiac anesthesiologists during 75 surgical procedures in which biplane TEE monitoring was used. Every 10 min intraoperatively, each anesthesiologist evaluated the video cine loop display of echocardiographic images to provide a real-time visual estimate of left ventricular ejection fraction area (EFA) and left ventricular filling at the level of the short axis and to assess regional wall-motion of the short axis and transgastric longitudinal views using a predefined scoring system. The same video images were analyzed quantitatively off-line by two blinded investigators. Intraoperative real-time estimates of EFA correlated moderately with off-line quantification (r = 0.8, P = 0.0001). Of the 662 cine loops analyzed by both off-line and real-time techniques, 386 (55%) were within +/-5% of each other, 495 (75%) were within +/-10% of each other, 561 (85%) were within +/-15% of each other, and 617 (93%) were within +/-20% of each other. The overall sensitivity and specificity of real-time echocardiographic ischemia detection were both 76%. However, there was individual variation among the five anesthesiologists. Recognition of normal and severe regional wall-motion abnormality, such as akinesis, had more concordance between real-time and off-line analysis, 93% and 79%, respectively, than recognition of mild regional wall-motion abnormalities. Anesthesiologists can estimate EFA in real-time to within +/-10% of off-line values in 75% of all cases. Real-time identification of normal regional function is more accurate than identification of abnormal function, i.e., there is variability in quantifying the severity of regional dysfunction.

Mechanisms of hemolysis with mitral prosthetic regurgitation. Study using transesophageal echocardiography and fluid dynamic simulation

OBJECTIVES

The aims of this study were to define the hydrodynamic mechanisms involved in the occurrence of hemolysis in prosthetic mitral valve regurgitation and to reproduce them in a numeric simulation model in order to estimate peak shear stress.

BACKGROUND

Although in vitro studies have demonstrated that shear stresses > 3,000 dynes/cm2 are associated with significant erythrocyte destruction, it is not known whether these values can occur in vivo in conditions of abnormal prosthetic regurgitant flow.

METHODS

We studied 27 patients undergoing reoperation for significant mitral prosthetic regurgitation, 16 with and 11 without hemolysis. We classified the origin and geometry of the regurgitant jets by using transesophageal echocardiography. By using the physical and morphologic characteristics defined, several hydrodynamic patterns were simulated numerically to determine shear rates.

RESULTS

Eight (50%) of the 16 patients with hemolysis had paravalvular leaks and the other 8 had a jet with central origin, in contrast to 2 (18%) and 9 (82%), respectively, of the 11 patients without hemolysis (p = 0.12, power 0.38). Patients with hemolysis had patterns of flow fragmentation (n = 2), collision (n = 11) or rapid acceleration (n = 3), whereas those without hemolysis had either free jets (n = 7) or slow deceleration (n = 4) (p < 0.001, power 0.99). Numeric simulation demonstrated peak shear rates of 6,000, 4,500, 4,500, 925 and 950 dynes/cm2 in these five models, respectively.

CONCLUSIONS

The distinct patterns of regurgitant flow seen in these patients with mitral prosthetic hemolysis were associated with rapid acceleration and deceleration or high peak shear rates, or both. The nature of the flow disturbance produced by the prosthetic regurgitant lesion and the resultant increase in shear stress are more important than the site of origin of the flow disturbance in producing clinical hemolysis.

Atrioventricular valve insufficiency and atrial geometry after orthotopic heart transplantation

BACKGROUND

The etiology of tricuspid and mitral valve regurgitation (TR and MR) after heart transplantation is still controversial.

METHODS

We studied 25 patients undergoing transplantation and intraoperative transesophageal echocardiography to evaluate the incidence, the degree, and the cause of TR and MR. The degree of valve regurgitation was assessed by color Doppler echocardiography. Cross-sectional areas of the recipient (R) and donor (D) portions of the atria and their ratio (R/D) were measured to assess the distortion of atrial geometry. Tricuspid and mitral valve annuli, their systolic shortening, and hemodynamic indices were measured preoperatively and perioperatively.

RESULTS

Tricuspid valve regurgitation was found in 21 of 25 patients (84%) and MR in 12 of 25 (48%). The degree of MR was mild, whereas TR was mild to moderate. Mitral valve regurgitation did not show any correlation with the studied indices; TR showed no correlation with the hemodynamic indices but a significant correlation with R/D ratio (r = 0.90; standard error of the estimate = 0.2). An inverse correlation was found between the degree of TR and systolic shortening of tricuspid annulus (r = -0.88; standard error of the estimate = 0.03) and between R/D ratio and systolic shortening of tricuspid annulus (r = -0.85; standard error of the estimate = 0.04).

CONCLUSIONS

Tricuspid valve regurgitation has a higher incidence than MR and occurs immediately after transplantation; MR is mild and correlates with neither hemodynamic indices nor atrial distortion. An increased R/D ratio, and hence distortion of right atrial geometry, may lead to a reduction in systolic annulus shortening, which in turn causes TR. Surgical attempts to reduce the R/D ratio may decrease the incidence and the degree of TR after heart transplantation.

Accuracy of intraoperative transesophageal echocardiography for estimating the severity of functional mitral regurgitation

Although intraoperative transesophageal echocardiography (TEE) is used to guide mitral valve reconstructive procedures, the effects of hemodynamic alterations accompanying general anesthesia on mitral regurgitation (MR) are unknown. This study was performed to evaluate the effect of general anesthesia on MR jet size using TEE with color Doppler imaging in patients undergoing mitral valve surgery. Matched preoperative TEEs performed with the patient under intravenous conscious sedation, and intraoperative studies performed with the patient under general anesthesia were retrospectively reviewed in 46 patients undergoing mitral valve surgery. Patients were divided into groups based on etiology of MR, including 21 patients with myxomatous degeneration and leaflet flail, 19 patients with structurally normal leaflets and functional regurgitation due to abnormal leaflet coaptation, and 6 patients with rheumatic mitral disease. On both preoperative and intraoperative studies, regurgitation was quantified using maximal jet area and jet diameter at the vena contracta on color flow Doppler. Patients with leaflet flail and patients with functional MR had similar measures of regurgitation severity on preoperative imaging. On intraoperative imaging, regurgitant jet size was unchanged compared with preoperative studies among patients with leaflet flail (jet diameter 1.04 +/- 0.26 vs 1.10 +/- 0.28 cm, area 9.8 +/- 4.5 vs 10.1 +/- 5.2 cm2 on preoperative studies), although jet size decreased significantly in patients with functional MR (jet diameter 0.79 +/- 0.33 vs 1.10 +/- 0.29 cm [p < 0.001], area 5.7 +/- 3.5 vs 10.0 +/- 3.8 cm2 [p < 0.001] on preoperative studies). These findings were not accounted for by variation in heart rate, blood pressures, echocardiographic instrumentation, or Doppler Nyquist limit.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of mitral regurgitation on left atrial thrombus and spontaneous echocardiographic contrast in patients with rheumatic mitral valve disease

The aim of this study was to investigate the influence of mitral regurgitation (MR) on left atrial (LA) thrombus formation and spontaneous echocardiographic contrast in patients with rheumatic mitral valve disease. LA thrombus and spontaneous contrast are considered risk factors for embolic complications. The presence of MR has been related to a low incidence of embolization; however, its effect on thrombus formation and spontaneous contrast has not been clarified. We studied by transesophageal echocardiography 55 patients with rheumatic mitral valve disease, who were receiving anticoagulant treatment. Atrial thrombus was detected in 13 patients who had a lower incidence of significant MR (p < 0.03), a smaller regurgitant jet (p < 0.02), and a higher incidence of atrial fibrillation (p < 0.05) than the rest of the group. Spontaneous contrast was detected in 34 patients with larger atria (p < 0.006), smaller regurgitant jets (p < 0.05), a smaller mitral valve area (p < 0.008), and a higher incidence of atrial fibrillation (p < 0.002) than the rest of the group. Patients without significant MR are at high risk for LA thrombus formation and subsequent embolization and represent a subgroup in whom careful anticoagulation is needed. Conversely, the presence of significant MR correlates with a lower incidence of spontaneous contrast, thrombi, and embolization.

Proximal jet size by Doppler color flow mapping predicts severity of mitral regurgitation. Clinical studies

BACKGROUND

Recent studies have shown that many instrument and physiological factors limit the ability of color Doppler total jet area within the receiving chamber to predict the severity of valvular regurgitation. In contrast, the proximal or initial dimensions of the jet as it emerges from the orifice have been shown to increase directly with orifice size and to correlate well with the severity of aortic insufficiency. Only limited data, however, are available regarding the value of proximal jet size in mitral regurgitation, and it has not been examined in short-axis or transthoracic views. The purpose of the present study, therefore, was to evaluate the relation between proximal jet size and other measures of the severity of mitral regurgitation.

METHODS AND RESULTS

In 49 patients, the anteroposterior height of the proximal jet as it emerges from the mitral valve was measured in the parasternal long-axis view; proximal jet width and area were measured in the short-axis view at the same level. Results were compared with regurgitant volume and fraction by pulsed Doppler subtraction of aortic and mitral flows in 47 patients without more than trace aortic insufficiency; with angiographic grade determined within 24 hours in 33 catheterized patients; and with angiographic regurgitant fraction in 13 patients who were in normal sinus rhythm and had no significant aortic and tricuspid insufficiency. Proximal jet height, width, and area correlated well with Doppler regurgitant volume and fraction (r = .86 to .95; SEE = 7.7 to 9.0 mL; 5.9% to 7.3%). Proximal jet size could also be used to distinguish angiographic grades of mitral regurgitation with minimal overlap (P < .0001) and correlated well with angiographic regurgitant fraction (r = .85 to .91; SEE = 4.1% to 5.1%).

CONCLUSIONS

Proximal jet size correlates well with established measures of the severity of mitral regurgitation. It is conveniently available with transthoracic clinical scanning and should be useful in the routine evaluation of patients with mitral regurgitation.

Clinical evaluation of left heart Doppler contrast enhancement by a saccharide-based transpulmonary contrast agent. The Levovist Cardiac Working Group

OBJECTIVES

A multicenter study was carried out to evaluate the efficacy with which SHU 508A enhances left heart Doppler signals and improves the clinical quantification of valve disease.

BACKGROUND

Poor signal-to-noise ratio often limits the Doppler interrogation of left heart flows. This problem may be resolved by the enhancement of Doppler signals by an ultrasound contrast agent capable of pulmonary transmission, such as the recently developed SHU 508A.

METHODS

Left heart contrast enhancement was tested for 1) continuous wave Doppler evaluation in 51 patients with aortic stenosis, 2) pulsed Doppler transthoracic evaluation of pulmonary venous flow in 85 patients, and 3) color Doppler evaluation of mitral regurgitation in 60 patients. Studies were performed immediately before and during the intravenous administration of SHU 508A (16 ml of 200 mg/ml) and compared with unenhanced transesophageal data in representative subsets of patients.

RESULTS

SHU 508A had no serious adverse effects. A significant increase in left heart Doppler signal intensity lasted for 30 to 300 s. The continuous wave Doppler velocity envelope was enhanced for all jets, but Doppler peak velocity was not altered in high quality baseline studies. However, Doppler contrast enhancement resulted in higher measured peak gradients (p < 0.001) in 29 patients with aortic stenosis who had poor quality baseline studies. This improved the overall correlation with invasive pressure measurements (r = 0.73 vs. r = 0.89, p < 0.01). The enhanced pulsed Doppler traces of transthoracic pulmonary venous flow allowed quantitative analysis in 92% patients (vs. 27% at baseline) and correlated well with peak velocities and velocity profiles obtained by transesophageal echocardiography (r = 0.91, p < 0.001). The enhanced color Doppler display of regurgitant jets increased jet area with a high interindividual variability (mean 276%), resulting in almost identical jet areas as unenhanced transesophageal values (r = 0.97, p < 0.001).

CONCLUSIONS

SHU 508A is a safe transpulmonary contrast agent that significantly enhances both spectral and color Doppler signals in the left heart. In specific patient subsets, the increase in signal-to-noise ratio improved the quantitative assessment of aortic stenosis, pulmonary venous flow and mitral regurgitation.

Doppler evaluation of severity of mitral regurgitation: relation to pulmonary venous blood flow patterns in an animal study

OBJECTIVES

This study examined the influence of regurgitant volume on pulmonary venous blood flow patterns in an animal model with quantifiable mitral regurgitation.

BACKGROUND

Systolic pulmonary venous blood flow is influenced by atrial filling and compliance and ventricular output and by the presence of mitral regurgitation. The quantitative severity of the regurgitant volume itself is difficult to judge in clinical examinations.

METHODS

Six sheep with chronic mitral regurgitation produced by previous operation to create chordal damage were examined. At reoperation the heart was exposed and epicardial echocardiography performed. Pulmonary venous blood flow waveforms were recorded by pulsed Doppler under color flow Doppler guidance using a Vingmed 750 scanner. The pulmonary venous systolic inflow to the left atrium was expressed as a fraction of the total inflow velocity time integral. Flows across the aortic and mitral valves were recorded by electromagnetic flowmeters balanced against each other. Pressures in the left ventricle and left atrium were measured directly with high fidelity manometer-tipped catheters. Preload and afterload were systematically manipulated, resulting in 24 stable hemodynamic states.

RESULTS

Simple logarithmic correlation between the regurgitant volume and size of a positive or negative pulmonary venous inflow velocity time integral during systole was good (r = -0.841). By stepwise linear regression analysis with pulmonary venous negative systolic velocity time integral as a dependent variable compared with the regurgitant volume, fractional shortening, left atrial v wave size, systemic vascular resistance and left ventricular systolic pressure, only contributions from v wave size and regurgitant volume (r = 0.80) reached statistical significance in determining pulmonary venous negative systolic flow.

CONCLUSIONS

Evaluation of systolic pulmonary venous blood flow velocity time integral can give valuable information helpful for estimating the regurgitant volume secondary to mitral regurgitation.

Does multiplane transesophageal echocardiography improve the assessment of prosthetic valve regurgitation?

Assessment of prosthetic valve regurgitation by echocardiography remains difficult. To study the value of the newly introduced multiplane transesophageal technology for this purpose, prosthetic valve regurgitation was examined in 63 consecutive patients with 35 mitral and 33 aortic prostheses (23 bioprostheses and 45 mechanical prostheses). Transvalvular, paravalvular and, in mechanical valves, normal or pathologic transvalvular regurgitation were identified first with 0 degrees (transverse) and 90 degrees (longitudinal) planes combined with flexion of the echoscope tip and then additionally with multiple intermediary planes by transducer rotation. In a subgroup of 20 patients interobserver variability was evaluated. Both methods showed regurgitation in 56 of 68 valves; one additional case of regurgitation was seen by multiplane imaging only. However, 19 cases of regurgitation were not clearly classifiable by biplane transesophageal echocardiography compared with only three with multiplane transesophageal echocardiography. Grading of severity was concordant by both modalities in 66 and discordant in only two cases. Observers disagreed on severity in two of 20 cases based on biplane imaging but in none based on multiplane imaging; classification of regurgitation differed in six of 20 (biplane) and one of 20 (multiplane), respectively. Multiplane transesophageal imaging improves classification of prosthetic regurgitation but has little effect on severity grading.