Limitations Of Transesophageal Echocardiography Research Articles

Intracardiac echocardiography‐guided transcatheter aortic valve replacement

Echocardiographic imaging is an essential component of successful transcatheter aortic valve replacement (TAVR). Currently, transesophageal echocardiography (TEE) is the imaging modality of choice for TAVR. However, a limitation of TEE is the need for general anesthesia and endotracheal intubation in most centers. Additionally, the TEE probe can obscure fluoroscopic views during valve positioning and deployment. Intracardiac echocardiography (ICE) has been used for imaging guidance for structural and valvular intervention, though its use has rarely been reported for primary imaging guidance during TAVR. Recently, a new volumetric three-dimensional intracardiac ultrasound (volume ICE) system has become available with the potential for improved visualization of intracardiac structures. We describe a recent TAVR case that was successfully performed with the use of volume ICE exclusively for imaging guidance. We found that assessment of valve positioning and aortic insufficiency were comparable to that provided by conventional TEE imaging, though there were several important limitations. ICE-guided TAVR may represent an important alternative to TEE for TAVR imaging guidance and possibly allow for less-intensive sedation or anesthesia.

Continuing Medical Education Program in Echocardiography

Article Title: Diagnosis of Congenital Unicuspid Aortic Valve in Adult Population: The Value and Limitation of Transesophageal Echocardiography (Echocardiography 2010;27:1106)

Diagnosis of Congenital Unicuspid Aortic Valve in Adult Population: The Value and Limitation of Transesophageal Echocardiography

This study aimed to assess the accuracy of two-dimensional echocardiography (echo) in diagnosing unicuspid aortic valve (UAV) and to determine echo features that could improve the diagnosis. We reviewed transthoracic/transesophageal echoes (TTE/TEE) from our hospital database for adult patients who had aortic valve surgery with a preoperative echo diagnosis of UAV or equivocal diagnosis of bicuspid aortic valve (BAV) BAV/UAV. Morphological characteristics of AV and ascending aortic dimensions were evaluated. Nineteen patients were identified, 13 (11 Male, 2 Female, mean age 47 ± 10 years) had surgically confirmed diagnosis of UAV, six had BAV. The incidence of UAV was 2.6%. For diagnosing UAV, the sensitivity and specificity of TTE was 27% and 50% and those of TEE was 75% and 86%, respectively. For TTE, positive predictive value (PPV) was 60% and negative predictive value (NPV) was 20%. By TEE, PPV was 90% and the NPV was 67%. In UAV patients, 85% had severe aortic stenosis (mean gradient 45 ± 16 mmHg, AVA: 0.9 ± 0.2 cm²). 46% had ascending aorta aneurysm (mean aortic root, sinutubular junction, ascending aorta dimensions: 36 ± 3 mm, 31 ± 4 mm and 41 ± 8 mm). Patients with ascending aortic aneurysm were younger (41 ± 11 years vs. 52 ± 5 years, P < 0.05) All UAV were unicommissural with a posteriorly positioned commissural attachment, 69% were heavily calcified. Diagnostic accuracy was limited by quality of images, severity, and distribution of calcification. TEE is the diagnostic modality of choice in UAV. Identifying several echo features may improve its diagnostic accuracy.

Case 1–2003 The use of intraoperative echocardiography during insertion of ventricular assist devices

Transesophageal echocardiography (TEE) assists in the intraoperative decision-making process during cardiac anesthesia and cardiac surgery. Mechanical ventricular support may be necessary to support the circulatory system temporarily or serve as a bridge to heart transplantation. A left ventricular assist device (LVAD) is most commonly used.1 Biventricular failure necessitates the use of an LVAD along with a right ventricular assist device (RVAD) to form a biventricular assist device (BIVAD) (Fig 1). TEE plays a vital role in evaluating effective mechanical assistance of the circulation.1-3 This case describes a BIVAD placement in a patient and shows the roles and limitations of TEE in this scenario.

Intraoperative transesophageal echocardiography for pediatric patients with congenital heart disease.

Intraoperative transesophageal echocardiography for pediatric patients with congenital heart disease.

Use of Transesophageal Echocardiography to Detect Unsuspected Massive Pulmonary Emboli

This report describes three patients in whom unsuspected large central pulmonary emboli were identified by transesophageal echocardiography. We discuss the utility and limitations of transesophageal echocardiography in diagnosing pulmonary emboli and its potential beneficial impact on the management of patients in the intensive care unit, particularly those with unexplained hypotension. (J Am Soc Echocardiogr 1998;11:751-4.)

Thromboembolism Following Cardioversion of “Common” Atrial Flutter: Risk Factors and Limitations of Transesophageal Echocardiography

Based on multiple recent studies, anticoagulant therapy is recommended prior to elective cardioversion for patients with atrial fibrillation of more than 24 h duration. The value of anticoagulation in patients with atrial flutter, however, is less well established. Published recommendations for pericardioversion anticoagulation of atrial fibrillation often do not extend to patients with atrial flutter. We evaluated the risk of thromboembolism in our patient population undergoing cardioversion for atrial flutter. Over a period of 30 months, clinically indicated electrical cardioversions were performed in 41 patients with "common" atrial flutter. Sixteen of these patients underwent transesophageal echocardiograms immediately prior to cardioversion to exclude a left atrial thrombus. Three of the 41 patients with atrial flutter developed neurologic ischemic syndromes within 48 h of elective cardioversion. All three patients who developed ischemic neurologic complications had undergone transesophageal echocardiography immediately prior to cardioversion and did not have any evidence of left atrial clot. One patient had cardiomyopathy and the other two had left ventricular hypertrophy. Thus, electrical cardioversion without anticoagulation in patients with atrial flutter and associated heart disease is associated with a risk of thromboembolic events. A normal transesophageal echocardiogram is of doubtful value in prevention of thromboembolic complications.

Limitations of transesophageal echocardiography in the risk assessment of patients before nonanticoagulated cardioversion from atrial fibrillation and flutter: An analysis of pooled trials: E. Moreyra, R.S. Finkelhor, R.D. Cebul. Division of Cardiology, Metro-Heath Medical Center, Cleveland, OH. Am Heart J 1995;129:71-5.

Limitations of transesophageal echocardiography in the risk assessment of patients before nonanticoagulated cardioversion from atrial fibrillation and flutter: An analysis of pooled trials: E. Moreyra, R.S. Finkelhor, R.D. Cebul. Division of Cardiology, Metro-Heath Medical Center, Cleveland, OH. Am Heart J 1995;129:71-5.

Diagnosis of aortic dissection: The value and limitations of transesophageal echocardiography

Aortic dissection requires prompt and reliable diagnosis. The purpose of this study was to assess the accuracy and limitations of transesophageal echocardiography (TEE) for the diagnosis of aortic dissection. Twenty seven patients with clinically suspected aortic dissection were investigated by means of TEE. TEE results were compared to intraoperative findings (n = 18), necropsy (n = 4), and magnetic resonance imaging (n = 5). The DeBakey classification was used for differentiation of dissection type. Twenty-three patients (85%) were correctly identified as having aortic dissection. Four false-positive TEE findings (15%) were confined to the nondissecting aneurysm of the ascending aorta in elderly patients. Retrospectively we found that protruding atherosclerotic plaques were recognized as small intimal flaps. Type of dissection was correctly diagnosed in all 23 patients, the primary entry site was identified in 15 patients (65%), aortic regurgitation was found in 55.5% of patients, and pericardial effusion was detected in 33.3%. We conclude that TEE allows accurate diagnosis and classification of aortic dissection. However, some cases could be overdiagnosed in lesions of the ascending aorta, especially in nondissecting aneurysms. Another limitation of TEE is the inability to define the primary entry site in some cases. Still, overall results may favor TEE as the primary bedside diagnostic procedure to identify patients requiring urgent surgical intervention.

Diagnosis of aortic dissection: The value and limitations of transesophageal echocardiography

Aortic dissection requires prompt and reliable diagnosis. The purpose of this study was to assess the accuracy and limitations of transesophageal echocardiography (TEE) for the diagnosis of aortic dissection. Twenty seven patients with clinically suspected aortic dissection were investigated by means of TEE. TEE results were compared to intraoperative findings (n = 18), necropsy (n = 4), and magnetic resonance imaging (n = 5). The DeBakey classification was used for differentiation of dissection type. Twenty-three patients (85%) were correctly identified as having aortic dissection. Four false-positive TEE findings (15%) were confined to the nondissecting aneurysm of the ascending aorta in elderly patients. Retrospectively we found that protruding atherosclerotic plaques were recognized as small intimal flaps. Type of dissection was correctly diagnosed in all 23 patients, the primary entry site was identified in 15 patients (65%), aortic regurgitation was found in 55.5% of patients, and pericardial effusion was detected in 33.3%. We conclude that TEE allows accurate diagnosis and classification of aortic dissection. However, some cases could be overdiagnosed in lesions of the ascending aorta, especially in nondissecting aneurysms. Another limitation of TEE is the inability to define the primary entry site in some cases. Still, overall results may favor TEE as the primary bedside diagnostic procedure to identify patients requiring urgent surgical intervention.

Limitations of transesophageal echocardiography in the risk assessment of patients before nonanticoagulated cardioversion from atrial fibrillation and flutter: An analysis of pooled trials

Recent studies have proposed that the exclusion of an atrial thrombus by transesophageal echocardiography (TEE) would allow for the safe cardioversion from atrial fibrillation or flutter without the need of prophylactic anticoagulation. Because all of the TEE trials have been small and descriptive and have lacked randomized, conventionally treated control groups, the pooled risk of embolic events from TEE trials was compared with that of a control group pooled from the literature on cardioversion both with and without conventional anticoagulation. Studies were identified from a MEDLINE search, references in review articles, and recent cardiology abstracts and were included if there were >10 patients and if atrial fibrillation or flutter was of >48 hours' duration. Where >1 study had been published by the same group only the largest study was used. Studies were not selected by cause of arrhythmia, by predisposing risk factors for atrial fibrillation and flutter, or by method of cardioversion. The only patients excluded from TEE reports were those with atrial thrombi diagnosed on the precardioversion TEE or those documented to have adequate standard precardioversion anticoagulation. Seven TEE and 18 control studies met the inclusion criteria. More patients in the control studies had rheumatic valvular disease. Embolic events were significantly more frequent in the TEE group than in the anticoagulated control group (1.34% vs 0.33%, respectively; p = 0.04), whereas there was no significant difference between the TEE group and the nonanticoagulated control group (2.00%; p = 0.26). Thus the use of TEE screening to exclude patients with atrial thrombi before cardioversion does not identify patients who can safely undergo this procedure without anticoagulation.

Southwestern Internal Medicine Conference: Clinical Applications of Transesophageal Echocardiography

Transesophageal echocardiography has emerged recently as a powerful cardiac imaging tool. The strengths and limitations of transesophageal echocardiography are reviewed. The clinical use of transesophageal echocardiography in aortic dissection, endocarditis, mitral valve disease, prosthetic heart valves, stroke, and miscellaneous other conditions is discussed.

Massive left atrial calcification: A limitation of transesophageal echocardiography

Massive left atrial calcification: A limitation of transesophageal echocardiography

Value and Limitations of Transesophageal Echocardiography in the Evaluation of Aortic Prostheses

Value and Limitations of Transesophageal Echocardiography in the Evaluation of Aortic Prostheses

Value and limitations of transesophageal echocardiography in the evaluation of aortic prostheses.

Results of 34 transesophageal (TEE) studies in patients with suspected aortic prosthetic dysfunction were compared with transthoracic echocardiographic (TTE) results and to anatomic findings. Mass lesions noted at surgery (autopsy) were correctly described in 93% by TEE versus 43% by TTE. Abscesses were detected in 88% by TEE versus 18% by TTE. Bioprosthetic degeneration was visualized in 88% versus 38% and prosthetic obstruction correctly identified in 75% versus 50% by TEE and TTE, respectively. Anatomic aortic regurgitant lesions were identified in 96% by TEE versus 77% by TTE, whereas the correct origin was detected in 88% of cases by TEE versus 54% of cases by TTE. TEE provides valuable additional information on morphologic conditions and flow pathology in aortic valve prostheses.

Value and limitations of transesophageal echocardiography in determination of left ventricular volumes and ejection fraction

Several formulas exist for estimating left ventricular volumes and ejection fraction using conventional two-dimensional echocardiography from transthoracic views. Transesophageal imaging provides superior resolution of endocardial borders but employs slightly different scan planes. The estimation of left ventricular volumes by transesophageal echocardiography has not been validated in human patients. Therefore, the purpose of this study was to compare left ventricular volumes and ejection fraction derived from transesophageal short-axis and four-chamber images with similar variables obtained from ventriculography.End-diastolic and end-systolic volumes and ejection fraction were calculated using modified Simpson's rule, area-length and diameter-length models in 36 patients undergoing left ventriculography. Measurements of left ventricular length were obtained from the transesophageal four-chamber view and areas and diameters were taken from short-axis scans at the mitral valve, papillary muscle and apex levels.Data from transesophageal echocardiographic calculations were compared with end-diastolic volume (mean 172 ± 90 ml), end-systolic volume (mean 91 ± 74 ml) and ejection fraction (mean 52 ± 15%) from cineventriculography using linear regression analysis. The area-length method (r = 0.88) resulted in a slightly better correlation with left ventricular end-diastolic volume than did Simpson's rule (r = 0.85) or area-length (r = 0.84) formulas. For end-systolic volume, the three models yielded similar correlations: Simpson's rule (r = 0.94), area-length (r = 0.93) and diameter-length (r = 0.95). Each of the methods resulted in significant underestimation of diastolic and systolic volumes compared with values assessed with angiography (p < 0.003).Ejection fraction was best predicted by using the Simpson's rule formula (r = 0.85) in comparison with area-length (r = 0.80) or diameter-length (r = 0.73) formulas. Measurements of left ventricular length by transesophageal echocardiography were smaller for systole (mean 5.7 ± 1.6 cm) and diastole (mean 7.7 ± 1.2 cm) than values by ventriculography (mean 9.2 ± 1.4 and 8.1 ± 1.6 cm, respectively: p < 0.0001), suggesting that underestimation of the ventricular length is a major factor contributing to the smaller volumes obtained by transesophageal echocardiography.In conclusion, currently existing formulas can be applied to transesophageal images for predicting left ventricular volumes and ejection fraction. However, volumes obtained by these models are significantly smaller than those obtained with angiography, possibly because of foreshortening in the transesophageal fourchamber view.

Value and limitations of transesophageal echocardiography in assessment of mitral valve prostheses : Khandheria BK, Seward JB, et al. Circulation 83:1956, 1991

Value and limitations of transesophageal echocardiography in assessment of mitral valve prostheses : Khandheria BK, Seward JB, et al. Circulation 83:1956, 1991

Usefulness and limitations of transesophageal echocardiography in the assessment of proximal coronary artery stenosis

To assess the usefulness of transesophageal echocardiography in the evaluation of proximal coronary artery stenosis, 111 consecutive patients (mean age 61 years) who had intraoperative transesophageal echocardiography and coronary angiography within 1 week of surgery were studied. Transesophageal echocardiography visualized the entire length of the left main artery (0.2 to 2.2 cm, mean 0.93), 0.2 to 2.2 cm of the proximal left anterior descending artery and 0.1 to 3.4 cm of the proximal left circumflex artery in 103 patients (93%) and 0.1 to 4.6 cm of the proximal right coronary artery in 55 patients (49%). In the coronary artery segments visualized by echocardiography and compared with the corresponding angiographic segments, transesophageal echocardiography correctly identified 23 (96%) of 24 left main stenoses, 11 (78%) of 14 stenoses involving the left anterior descending artery, 6 (75%) of 8 left circumflex stenoses and all 7 stenoses (100%) of the right coronary artery. In all seven patients with ostial stenosis (left main artery in five and right coronary artery in two), the condition was correctly diagnosed by this technique. The sensitivity and specificity of transesophageal echocardiography in the overall evaluation of proximal coronary artery stenosis as customarily defined by angiography were 96% and 99% for the left main artery, 48% and 99% for the left anterior descending artery, 67% and 100% for the left circumflex artery and 37% and 100% for the right coronary artery, respectively. The distance of the stenotic lesion from the origin of the vessel by transesophageal echocardiography also correlated well with that measured by angiography (r = 0.63 to 0.99).(ABSTRACT TRUNCATED AT 250 WORDS)

Value and limitations of transesophageal echocardiography in evaluating prosthetic or bioprosthetic valve dysfunction

Optimal management of patients with prosthetic heart valves requires serial assessment of valve function. The addition of Doppler and color flow techniques to conventional transthoracic echocardiography (TTE) has increased our ability to evaluate prosthetic valve function. However, the sensitivity of TTE remains limited in a number of patients because of suboptimal precordial windows or because of ultrasound interference with the nonbiologic materials composing the prostheses. 1–3 Transesophageal echocardiography (TEE) allows excellent imaging resolution of the cardiac anatomy without interposition of thoracic structures. Recently, TEE has been shown to increase the yield of undetected prosthetic valve abnormalities by TTE. 4–8 However, most of the TEE information relates to biologic prostheses in the mitral position. 5–8 Thus, the purpose of this study was to investigate the diagnostic accuracy of TEE in evaluating mechanical and biologic prostheses in both aortic and mitral positions, and the impact of the TEE information on the clinical outcome.

Value and limitations of transesophageal echocardiography in assessment of mitral valve prostheses.

Transthoracic Doppler echocardiography examination has become an integral part of the investigations performed in patients with mitral valve prostheses. The limitations of the transthoracic approach are well documented. Transesophageal echocardiography provides a unique window for achieving a clear view of the mitral prosthesis. This study shows the usefulness of transesophageal echocardiography in clinical practice for assessment of patients with a mitral valve prosthesis. This technique demonstrated an abnormality in 48% of patients who had normal results on transthoracic examination. The overall sensitivity of transesophageal echocardiography was 96%. Transesophageal echocardiography constitutes an essential part of a comprehensive two-dimensional/Doppler echocardiographic examination in patients with suspected malfunction of mitral prostheses.