Transesophageal biplane echocardiographic imaging: technique, planes, and clinical usefulness

The technique of examination, imaging planes, and the clinical utility of transesophageal biplane echocardiography are described.     

Pediatric transesophageal color flow imaging 1990: the long and short of it

Noninvasive cardiac imaging has dramatically altered the practice of cardiology, specifically, the pediatric patient with congenital heart disease over the past decade. Since the introduction of transesophageal echocardiography nearly 15 years ago, addition of high-resolution cross-sectional imaging combined with Doppler color flow mapping has provided a new window to examine the heart. Recently, miniaturization of the transesophageal probe to "pediatric-size" has enabled its use in the smallest of infants to add significantly to the assessment of congenital heart malformations. Most recently, addition of a longitudinal-plane probe to the already-existent, transverse-plane probe has made biplane transesophageal echocardiography a reality with significant additional information being provided by orthogonal images of the cardiac structures. We used these probes in complementary fashion in 30 studies performed in 23 patients ages 1 day to 12 years with a mean of 35 months, weighing 2.6-40 kg (mean 12.4 kg). These studies were performed in the operating room, intensive care unit, cardiac catheterization laboratory, and outpatient department. Limitations of single-plane, transverse transesophageal echocardiography were overcome using the longitudinal-axis pediatric probe: left and right ventricular outflow tracts, distal pulmonary arteries, and all of the interventricular and atrial septa were easily visualized. Its use in the operating room and postoperative cardiac intensive care unit for continuous ventricular monitoring in otherwise-inaccessible patients also provided critical information. Transesophageal echocardiography in infants and small children is a valuable "noninvasive" imaging technique which, with addition of complementary longitudinal-plane views, offers important additional information regarding congenital heart malformations and their repair.     

New direction of biplane transesophageal echocardiography with special emphasis on real-time biplane imaging and matrix phased-array biplane transducer

This article reports on the technical aspects of an online real-time biplane transesophageal echocardiographic imaging system and of a single-matrix, phased-array transducer capable of transverse and longitudinal scanning.     

Future technical prospects in biplane transesophageal echocardiography: use of adult and pediatric biplane matrix probes

This study evaluates the feasibility of the combined use of an adult matrix probe with a real-time biplane imaging system, and also describes the performance of a newly developed pediatric matrix probe.     

Impact of transesophageal color flow Doppler echocardiography in current cardiology practice

Of 3,480 patients who were referred for cardiac ultrasound evaluation, 230 patients (6.6%) underwent transesophageal echocardiography because the transthoracic study was not feasible, technically inadequate, or provided insufficient diagnostic information for optimal patient management. There were 149 inpatients and 81 outpatients. The majority (182 patients, 79%) had aortic or mitral disorders. In 166 patients (72%), transesophageal echocardiography played a significant role in patient management. Transesophageal echocardiography was most useful in evaluating diseases of the aorta (dissection, root abscess, or aneurysm), mitral prosthesis, complications of endocarditis, left atrial appendage thrombi, and in determining the cause of mitral insufficiency. Transesophageal echocardiography was useful in the evaluation of critically ill patients and those with severe lung disease.     

Panoramic transesophageal echocardiography. Clinical application of real-time, wide-angle, transesophageal two-dimensional echocardiography and color flow imaging

Panoramic transesophageal echocardiography is a new development in transesophageal echocardiography (TEE) technology, which yields a wide-angle imaging field for real-time two-dimensional and color flow imaging. We report our early experience in patients with the use of an annular-array TEE probe that provides a wide, 270 degrees angle imaging field for two-dimensional echocardiographic imaging. The field of view can, however, be narrowed to 15 degrees . The field of view for color flow imaging can be varied from 180 degrees to 10 degrees . Pulsed-Doppler recordings of flow velocity are also possible. This TEE system provides a panoramic vision of cardiac and paracardiac structures from the esophagus and stomach. Besides cardiovascular structures, other thoracic and upper abdominal organs can be visualized. The wide field of view allows a better comprehension of the cardiac anatomy and its relationship with adjacent structures. The initial experience suggests that this method, besides providing the usually required diagnostic information, may have a number of additional applications. Its clinical potential and directions for future developments are reviewed.     

Quantification of mitral regurgitation: a comparison of transesophageal echocardiography and contrast ventriculography

Transesophageal echocardiography (TEE) allows an unobscured view of the left atrium for the assessment of mitral regurgitation (MR). However, criteria for assessing MR by TEE have not been carefully validated. In order to determine and validate criteria for the assessment of MR severity, 65 clinically stable patients with a TEE color Doppler study and contrast ventriculography within a 2-week period were identified. Maximal or peak mitral regurgitation jet area to left atrial area ratio (MR/LA) derived solely from TEE imaging had the best correlation to MR severity by contrast ventriculography (r = 0.89). Utilizing MR jet area without correction for LA size resulted in r = 0.72 to 0.75. Utilizing LA area data from transthoracic echocardiograms in a subset of 29 patients resulted in r = 0.77. Best sensitivity and specificity for the assessment of MR by TEE were obtained using the following criteria: Peak MR/LA of 0%-9% predicts 0 + MR; 10%-28% 1 + MR; 29%-54% 2 + to 3 + MR; and greater than 55% 4 + MR. Best sensitivity and specificity occurs for assessment of 0 + and 4 + MR. Considerable overlap in data occurs in the 1 + and 3 + MR range utilizing the above stated criteria. Peak MR/LA ratio derived from a single TEE view in which the MR jet is maximally imaged is the best determinant of MR severity.     

Assessment of aortic regurgitation by transesophageal echocardiography: correlation with angiographic determination

Transthoracic echocardiographic studies have shown that color Doppler mapping of the aortic regurgitation (AR) jet correlated well with the severity of regurgitation as assessed by contrast aortography. The present study was performed to assess whether these parameters could be similarly applied to measurements determined by transesophageal echocardiography (TEE). In order to determine and validate criteria for the assessment of AR severity, 39 clinically stable patients with a TEE color Doppler study and contrast aortography within a 2-week period were identified. The ratio of the jet area (JA) to left ventricular diastolic area (LVDA) had the best correlation to AR severity as determined by contrast aortography (r = 0.89). Jet length, JA, the ratio of jet width to the width of the left ventricular outflow tract and jet width had r values of 0.88, 0.88, 0.83, and 0.84, respectively. The best sensitivity and specificity for the assessment of AR by TEE were obtained as follows: JA/LVDA ratio of 0%-7% predicts 0-1 + AR; 8%-20% 2-3 + AR, and greater than 20% 4 + AR. Of the three patients miscategorized, none was misgraded by more than one angiographic grade of AR. Jets that measure more than 6 cm in length or have an area of greater than 10 cm 2 have a 100% sensitivity and specificity for diagnosing 4 + AR. In the present study the ratio of JA to LVDA area correlates best with AR severity as determined by angiography.     

Quantification of mitral regurgitation: comparison between transthoracic and transesophageal color Doppler flow mapping

We reviewed transthoracic (TTE) and transesophageal (TEE) echocardiograms of 100 consecutive patients: 63 male, 37 female, mean age 50 years (range 16-83 years), 32 with neoplastic disease, 18 aortic disease, 28 mitral valve disease, and 22 with other diseases. Absence or presence of mitral regurgitation (defined as mild, moderate, or severe) was assessed. TEE showed mild mitral regurgitation in 26 patients where TTE was negative. The overall estimate of regurgitant lesion severity was concordant at TEE and TTE in 64% of cases. The overall estimate of regurgitant lesion severity was also greater by one grade in 1% of cases at TTE, and in 35% of cases at TEE. Maximal digitized jet areas were 3.60 +/- 6.35 cm 2 at TTE and 3.04 +/- 3.79 cm 2 at TEE (P = NS). Correlation was r = 0.69 (TEE = 0.41 TTE + 1.55; P less than 0.001). TEE yielded a higher prevalence of mitral regurgitation than TTE with a trend toward greater overall estimate of mitral regurgitation at the semi-quantitative analysis. TTE and TEE showed similar mean results at the quantitative assessment of maximal jet areas. However, a highly significant random variability was observed in quantifying mitral regurgitation at TEE.     

Multiplane transesophageal echocardiography. Imaging planes, echocardiographic anatomy, and clinical experience with a prototype phased array OmniPlane probe

Multiplane transesophageal echocardiography is a new exciting development in echocardiography. We examined the methodology and echo-anatomic correlations of multiplane transesophageal echocardiography and its clinical applications in 100 patients. We used a 5-MHz phased array multiplane (OmniPlane) transesophageal probe. In this instrument, the transducer array can be steered through 180 degrees from any transducer location. This provides a vast assembly of imaging planes, allowing for detailed visualization of all dimensions of cardiac anatomy. This report presents our observations on the echocardiographic anatomy seen in various image planes and the unique clinical potential of multiplane transesophageal echocardiography in the diagnostic assessment of cardiovascular disorders. This technique appears to provide incremental diagnostic information that enhances the interpretative ability. Less esophageal probe manipulation is required with consequent decrease in patient discomfort. We conclude that multiplane transesophageal echocardiography enhances the versatility of transesophageal examination and offers many new avenues for developments such as three-dimensional echocardiography.     

Quantification of mitral regurgitation by the proximal flow convergence method--comparison of transthoracic and transesophageal echocardiography

BACKGROUND: No dataexist to indicate whether transthoracic (TTE) and transesophageal echocardiography (TEE) are of comparable value for the detection and quantification of mitral regurgitation using the proximal flow convergence method. HYPOTHESIS: The study was performed to compare the value of TTE and TEE for the detection and quantification of mitral regurgitation using this method. METHODS: The study included 57 patients with and 11 patients without mitral regurgitation. In all patients, the proximal flow convergence region was imaged by transthoracic and transesophageal color Doppler echocardiography, and proximal isovelocity surface area radii were determined. In 19 patients, monoplane TEE and in 49 patients multiplane TEE was performed. Thirty-one patients with mitral regurgitation underwent cardiac catheterization. RESULTS: Both methods had a comparable sensitivity for the detection of mitral regurgitation. Proximal isovelocity surface area radii derived from TTE and TEE agreed moderately (mean difference -0.5 +/- 1.3 mm). TTE and TEE correlated significantly with the angiographic grade (rank correlation coefficients 0.83 and 0.81), and both differentiated mild to moderate from severe mitral regurgitation with an accuracy of 90%. Regurgitant volumes derived from both echocardiographic techniques and cardiac catheterization correlated moderately (correlation coefficients between 0.67 and 0.81). CONCLUSIONS: TTE and TEE were of comparable value for the detection and quantification of mitral regurgitation using the proximal flow convergence method.     

Intraoperative epicardial echocardiography: technique and imaging planes

With the recent innovations in cardiac surgical techniques, there is need for an immediate and reliable way to assess results in the operating room. Intraoperative epicardial echocardiography with Doppler color flow mapping provides an accurate and rapid imaging modality to assess the anatomical and functional results of cardiac surgery. This gives the surgeon a way to determine whether the hemodynamic abnormality has been successfully eliminated, prior to closure of the chest. After enclosure in a sterile sheath, a standard echocardiographic transducer is placed directly onto the epicardial surface. The heart is imaged in multiple tomographic planes developed specifically for intraoperative use: the parasternal equivalent; aortopulmonary sulcus; subcostal equivalent; and aorta-superior vena cava transducer positions. Two-dimensional echocardiography is useful to assess the morphology of valves and the size and function of cardiac chambers. Doppler color flow mapping provides a semi-quantitative assessment of the severity and physiological mechanism of valvular regurgitation. Continuous-wave Doppler echocardiography is used to estimate gradients across stenotic valves. This comprehensive appraisal of cardiac anatomy and flow is useful in the pre- or postcardiopulmonary bypass phase of cardiac surgery. This review focuses on the technique of intraoperative echocardiography and its applications in valve reconstruction operations with specific emphasis on the epicardial imaging planes.     

Assessment of Aortic Coarctation and Collateral Circulation By Biplane Transesophageal Echocardiography

Our experience in using biplane transesophageal echocardiography in the assessment of coarctation of the aorta is described.     

Routine use of transesophageal echocardiography and color flow imaging in the evaluation and treatment of children with congenital heart disease

We reviewed our experience with transesophageal echocardiography (TEE) and color flow imaging in 157 consecutive patients with known or suspected heart disease to ascertain the impact of this technology on patient care. TEE was performed for diagnostic purposes (22/157), during interventional cardiac catheterizations (13/157), and during operative procedures (122/157). Diagnostic studies were performed after transthoracic echocardiography (TTE) in 21 of 22 patients. TEE was performed because TTE was inconclusive (15/21) or failed to provide sufficient detail of an abnormality (6/21). TEE detected an abnormality in 6 of 15 inconclusive TTEs. TEE was helpful during interventional cardiac catheterizations, particularly during umbrella closure of septal defects and in patients with complex venous and atrial anatomy undergoing transseptal puncture. TEE studies performed before cardiac operations significantly changed the diagnosis in only 5 of 122 (4%) patients, but the information changed the surgical approach in 4 of 5 of these patients. Postoperative TEE assessment more frequently changed care and resulted in further surgical management in 9 of 122 (7%) or a change in medical management in 6 of 122 (5%) patients. TEE was discontinued because of complications before studies were completed in only 4 of 157 (3%) patients. TEE and color flow imaging is a useful adjunct to care of children with known or suspected congenital heart disease.     

A technique for performing transesophageal echocardiography in patients with Zenker's diverticulum

A patient with a large Zenker's diverticulum and narrow, angulated passageway successfully underwent transesophageal echocardiography using a pediatric endoscope, short esophageal overtube, and a pediatric transesophageal echocardiographic probe.     

Comparison of left atrial dimensions by transesophageal and transthoracic echocardiography

Transesophageal echocardiography (TEE) is an established cardiovascular diagnostic technique. Left atrial (LA) size, as measured by transthoracic echocardiography (TTE), is associated with cardiovascular disease and is a risk factor for atrial fibrillation, stroke, death, and the success of cardioversion. Assessment of LA size has not been as well validated on TEE as on TTE. We determined LA size measurements in four standard views in 122 patients undergoing TEE and TTE at the same setting. In this study, we found that measurement of LA dimensions by TEE suffers from significant limitations in all views except the basal long-axis view (mid-esophageal level) with transducer plane at 120-150 degrees. This view had the best correlation with transthoracic LA measurements: r = 0.79 for TEE long axis (CI 0.71-0.85), P <.0001.     

Intraoperative transesophageal echocardiography using high resolution imaging in infants and children with congenital heart disease

A transesophageal probe recently has been developed for use in pediatric patients, which incorporates 48 rather than 26 elements, and permits continuous-wave Doppler, and pulsed and color Doppler flow modalities. This probe potentially offers significantly enhanced image quality. To evaluate its capabilities, we tested the probe intraoperatively in 53 infants and children undergoing surgical repair of congenital heart disease, and found that clear echocardiographic images with good detail were provided, including the ability to image coronary arteries in patients weighing as little as 2.7 kg. Imaging detail transesophageally is commensurate with the performance of this system from a transthoracic route. This probe also has the capacity for accurate estimates of high velocity jets using continuous-wave Doppler, which is a relatively new development.     

Vegetation biopsy using transesophageal echocardiography guidance: A technique to aid in diagnosis of culture-negative endocarditis

A method of obtaining a vegetation sample in a culture-negative endocarditis is described. A combination of fluoroscopy and transesophageal echocardiography was utilized to obtain the sample. The results positively influenced the diagnosis and treatment in this 16-yr-old male with complex congenital heart disease. © 1996 Wiley-Liss, Inc.     

Comparison between transesophageal echocardiography and transthoracic echocardiography with harmonic tissue imaging for left atrial appendage assessment

BACKGROUND: Transesophageal echocardiography (TEE) is the method of choice for evaluating both anatomy and function of left atrial appendage (LAA). In contrast, conventional transthoracic echocardiography (TTE) does not result in images of sufficient quality to explore LAA. HYPOTHESIS: The aim of this study was to evaluate the potential role of TTE with harmonic frequency imaging (HFI) for assessing LAA normal anatomy and function. METHODS: The study group comprised 25 patients, (9 men, 16 women, mean age 51 years, range 20-82). The TTE as sessment of LAA both in fundamental frequency imaging (FFI) and HFI was performed using the apical two-chamber view, the longitudinal two-chamber view was used for TEE assessment of LAA. According to image quality, images were categorized into three classes: A: good quality, B: sufficient quality, C: poor quality. RESULTS: Transthoracic echocardiography conventional imaging allowed sufficient LAA visualization (class B) in only 5 of 25 patients (20%); the HFI resulted in adequate LAA visualization in 23 of 25 patients (92%). Images were of good quality (class A) in 18 of 23 patients and of sufficient quality (class B) in 5 of 23 patients. Transesophageal echocardiography achieved good quality images in 24 of 25 patients (96%). Average LAA maximum area determined by HFI and TEE was 3.46 +/-1.17 and 3.59 +/- 1.16 cm2, respectively; LAA minimum area was 1.81 +/- 0.98 and 1.77 +/- 0.97 cm2, respectively. Percent LAA area change was 51 +/- 16.5 and 50.9 +/- 16% with HFI and TEE, respectively. Statistical analysis showed no difference between the data obtained with the two methods. CONCLUSIONS: The results suggest that HFI TNE may be a useful tool for the exploration of LAA.