Comparison of transthoracic and transesophageal echocardiography in evaluation of 47 Starr-Edwards prosthetic valves.

OBJECTIVES. Our objectives were to characterize by transesophageal echocardiography the normal appearance of the Starr-Edwards prosthetic heart valve and to compare the utility of transesophageal and transthoracic echocardiography in detection of valve abnormality. BACKGROUND. The Starr-Edwards prosthetic heart valve, the first mechanical valve to be used, has demonstrated excellent durability. METHODS. Fifty transthoracic and transesophageal echocardiographic studies on 37 patients with 47 Starr-Edwards prosthetic valves were analyzed retrospectively. Six cases of surgically confirmed infective endocarditis were studied. RESULTS. Vegetation or abscess formation, or both, was identified by transesophageal echocardiography in all six cases of infective endocarditis but was found in only one of these cases by transthoracic echocardiography. Thrombus was detected by transesophageal echocardiography in 9 of 11 patients with transient ischemic attacks or stroke and in 2 patients by transthoracic echocardiography with 3 confirmed at surgery. In 26 of the 30 patients with a mitral Starr-Edwards valve, the valve demonstrated a trivial or mild "closing volume" early systolic or holosystolic leak on transesophageal echocardiography alone. Transthoracic evaluation identified significant mitral regurgitation in six of the eight patients who had this finding on transesophageal echocardiography. Serial studies were performed to assess response to treatment or need for surgical intervention in eight patients. Seventeen valves have been implanted for 12 years; six of these had significant leakage without apparent cause, a finding not observed more recently implanted valves. CONCLUSIONS. These observations demonstrated the unique utility of transesophageal echocardiography in patients with Starr-Edwards prosthetic valve dysfunction, endocarditis or thrombus formation, and of the clear superiority of transesophageal echocardiography over transthoracic echocardiography in these situations.     

Transesophageal two-dimensional echocardiography: its role in solving clinical problems

The diagnostic value of transesophageal two-dimensional echocardiography is described in 32 patients in whom precordial echocardiography or angiography, or both, failed to establish a definitive diagnosis. All attempted transesophageal studies were completed without complication and the referral question was definitively answered. Nineteen patients were subsequently submitted to surgery. In 18 of them, the transesophageal echocardiographic diagnoses were proven correct; in 1 patient, the diagnosis was proven partially incorrect. In the 13 unoperated patients the transesophageal echocardiographic diagnoses were not independently confirmed but were assumed correct because incontrovertible images were obtained. These results indicate that transesophageal echocardiography significantly extends the diagnostic capabilities of echocardiography.     

Comparison of transthoracic and transesophageal echocardiography for assessment of left-sided valvular regurgitation

To compare transthoracic and transesophageal echocardiography in the clinical assessment of left-sided valvular regurgitation, 118 patients who underwent both transesophageal and transthoracic echocardiographic studies within a 24-hour period were included in this study. Presence or absence of aortic regurgitation was identified concordantly by both techniques in 93 patients (79%). Complete agreement between both techniques was found in 88 patients (75%). Presence or absence of mitral regurgitation was identified concordantly by both techniques in 89 patients (75%). Complete agreement in grade was found in only 74 patients (63%). Twentynine patients (25%) had mitral regurgitation detected by transesophageal echocardiography, but not by transthoracic echocardiography. Four of these patients (14%) had significant (2 to 3+) mitral regurgitation. Differences between transesophageal and transthoracic echocardiography do not appear to be clinically important in patients with aortic regurgitation. In mitral regurgitation, significant differences exist between these 2 techniques, with transesophageal echocardiography being much more sensitive.     

Improved detection of infective endocarditis with transesophageal echocardiography.

The incremental advantage of transesophageal echocardiography was determined by comparing results of paired transthoracic and transesophageal echocardiographic examinations performed in 61 patients for evaluation of suspected infective endocarditis. According to clinical and pathologic data, 31 of 61 (51%) patients had finding that were positive for infective endocarditis. Studies were graded as positive or negative for vegetations and were also graded for image quality. The sensitivity of transesophageal echocardiography in detecting vegetations was 88% versus 30% for transthoracic studies (p less than 0.01). For patients with aortic valve infective endocarditis, transesophageal sensitivity was 88% versus 25% for transthoracic sensitivity, because transesophageal echocardiography successfully separated vegetations from chronic valve disease caused by sclerosis or calcification (p less than 0.01). For patients with mitral valve infective endocarditis, transesophageal sensitivity was 100% versus 50% for transthoracic sensitivity, because transesophageal echocardiography distinguished vegetations from myxomatous changes or detected vegetations on prosthetic valves (p less than 0.01). Thus transesophageal echocardiography improves recognition of infective endocarditis, particularly in the presence of underlying valvular disease.     

Comparison of transthoracic and transesophageal assessment of prosthetic valve dysfunction

Transesophageal echocardiography has added another dimension to the assessment of prosthetic valve dysfunction with high-resolution images that allow for more detailed structural evaluation of tissue and mechanical valves. This study is a retrospective analysis of 140 prosthetic valves (90 tissue, 50 mechanical) in the mitral (89), aortic (45), and tricuspid (6) position in 116 patients studied by transthoracic and transesophageal echocardiography techniques. Transesophageal echocardiography was consistently better than the transthoracic technique in the evaluation of structural abnormalities of tissue valves in the mitral and aortic positions with respect to leaflet thickening, prolapse, flail, and vegetations. With transesophageal echocardiography, five tissue mitral valves had flail leaflets that were not identified by the transthoracic technique. Transesophageal echocardiography was better than transthoracic in the detection, quantification, and localization of prosthetic mitral regurgitation. Physiological mitral regurgitation was detected in 31 valves by transesophageal echocardiography compared to seven by transthoracic technique. By transesophageal echocardiography, mitral regurgitation was paravalvular in 24% compared with 4% by transthoracic technique. Left atrial spontaneous contrast was seen in 42% of the patients with a mitral prosthesis detected only by transesophageal echocardiography. Six patients had left atrial or left atrial appendage thrombus and in five patients they were detected only by transesophageal echocardiography. We conclude that transesophageal echocardiography should be a complimentary test to transthoracic studies in patients with suspected prosthetic valve dysfunction or for the follow-up of older tissue valves.     

The improved yield of transesophageal echocardiography over transthoracic echocardiography in patients with neurological events is largely due to the detection of aortic protruding atheromas

It is important to determine what, if any, the added contribution of transesophageal echocardiography is to the evaluation of patients with unexplained strokes and transient ischemic attacks. Transesophageal echocardiography was performed in 283 consecutive patients over an 8-month period. The reason for referral in 63 of these patients was unexplained stroke or transient ischemic attack. These 63 studies were evaluated for the presence of lesions that could be etiologic in these patients, including protruding aortic atheromas, spontaneous echo contrast, atrial septal aneurysms, and atrial clots. The transesophageal and transthoracic techniques were compared. The main finding was that there were 23 abnormal findings that might have been responsible for stroke or transient ischemic attacks seen on transesophageal echocardiography, which were not visualized on transthoracic echocardiography. Transthoracic echocardiography was false negative in 19 (30%) of 63 patients. None of the protruding aortic arch atheromas seen on transesophageal echocardiography were diagnosed with transthoracic echocardiography. Transesophageal echocardiography is indicated in the evaluation of patients with unexplained strokes and transient ischemic attacks, and the added yield of this technique is largely due to the finding of protruding aortic arch atheromas.     

Superiority of transesophageal echocardiography in detecting cardiac source of embolism in patients with cerebral ischemia of uncertain etiology

The diagnostic yield of transesophageal and transthoracic echocardiography for identifying a cardiac source of embolism was compared in 79 patients presenting with unexplained stroke or transient ischemic attack. There were 35 men and 44 women with a mean age of 59 years (range 17 to 84); 52% had clinical cardiac disease. Both transthoracic and transesophageal echocardiograms were performed using Doppler color flow and contrast imaging. Transesophageal echocardiography identified a potential cardiac source of embolism in 57% of the overall study group compared with only 15% by transthoracic echocardiography (p less than 0.0005). Compared with transthoracic echocardiography, transesophageal echocardiography more frequently identified atrial septal aneurysm associated with a patent foramen ovale (9 versus 1 of 79 patients, p less than 0.005), left atrial thrombus or tumor (6 versus 0 of 79 patients, p less than 0.05) and left atrial spontaneous contrast (13 versus 0 of 79 patients, p less than 0.0005). All cases of left atrial thrombus or spontaneous contrast were identified in patients with clinically identified cardiac disease. In the 38 patients with no cardiac disease, transesophageal echocardiography identified isolated atrial septal aneurysm and atrial septal aneurysm with a patent foramen ovale more frequently than transthoracic echocardiography (8 versus 2 of 38 patients, p less than 0.05). The two techniques had a similar rate of identifying apical thrombus and mitral valve prolapse. Overall, transesophageal echocardiography identified abnormalities in 39% of patients with no cardiac disease versus 19% for transthoracic echocardiography (p less than 0.005). Thus, transesophageal echocardiography identifies potential cardiac sources of embolism in the majority of patients presenting with unexplained stroke.(ABSTRACT TRUNCATED AT 250 WORDS)     

Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma

Objectives. The purpose of this study was to evaluate the diagnostic accuracy of biplane and multiplane transesophageal echocardiography in patients with suspected aortic dissection, including intramural hematoma.Background. Transesophageal echocardiography is a useful technique for rapid bedside evaluation of patients with suspected acute aortic dissection. The sensitivity of transesophageal echocardiography is high, but the diagnostic accuracy of biplane and multiplane transesophageal echocardiography for dissection and intramural hematoma is less well defined.Methods. We studied 112 consecutive patients at a major referral center who had undergone biplane or multiplane transesophageal echocardiography to identify aortic dissection. The presence, absence and type of aortic dissection (type A or B, typical dissection or intramural hematoma) were confirmed by operation or autopsy in 60 patients and by other imaging techniques in all. The accuracy of transesophageal echocardiography for ancillary findings of aortic dissection (intimal flap, fenestration and thrombosis) was assessed in the 60 patients with available surgical data.Results. Of the 112 patients, aortic dissection was present in 49 (44%); 10 of these had intramural hematom (5 with and 5 without involvement of the ascending aorta). Of the remaining 63 patients without dissection, 33 (29%) had aortic aneurysm and 30 (27%) had neither dissection nor aneurysm. The overall sensitivity and specificity of transesophageal echocardiography for the presence of dissection were 98% and 95%, respectively. The specificity for type A and type B dissection was 97% and 99%, respectively. The sensitivity and specificity for intramural hematoma was 90% and 99%, respectively. The accuracy of transesophageal echocardiography for diagnosis of acute significant aortic regurgitation and pericardial tamponade was 100%.Conclusions. Biplane and multiplane transesophageal echocardiography are highly accurate for prospective identification of the presence and site of aortic dissection, its ancillary findings and major complications in a large series of patients with varied aortic pathology, Intramural hematoma carries a high complication rate and should be treated identically with aortic dissection.     

Sizing of atrial septal defects to predict successful closure with transcatheter cardioSEAL device.

We conducted this retrospective study to compare methods for measuring atrial septal defects and to identify factors affecting echocardiographic measurement of such defects before transcatheter closure with the CardioSEAL'Septal Occluder. We reviewed the records of patients considered for device placement at our institution from January 1997 to April 1999. Atrial septal defect size was measured by transthoracic and transesophageal echocardiography; the stretched diameter was measured during catheterization by fluoroscopy and transesophageal echocardiography. The stretched-diameter fluoroscopic measurement was used for device size selection. Analysis of variance was used to calculate the effect of size, age, and size-by-age interaction. Thirty-one patients (3.3 to 72 years of age) underwent transthoracic and transesophageal echocardiography One patient was excluded from catheterization because of a 25-mm septal defect as indicated by transesophageal echocardiography (our maximum diameter, 15 mm). Thirty patients underwent transcatheter stretched-diameter sizing; 5 were excluded from device implantation because of defects >20 mm by stretched-diameter fluoroscopy (4) or septal length insufficient for device support (1). Implantation was successful in 23/25 patients; 2/23 had a residual shunt. In patients with available results (26/30), the stretched diameter was the same whether measured by stretched-diameter fluoroscopy or transesophageal echocardiography (P=0.007 R square=0.963). Compared with stretched-diameter fluoroscopy, precatheterization transthoracic and transesophageal echocardiography underestimated defect size by a mean of 22% and 13.2%, respectively. When data from those same tests were compared in defects of < or =0 mm and > 10 mm, transthoracic and transesophageal echocardiography were reliable predictors (P=0.003 and P=0.05, respectively) of stretched-diameter size in defects < or =0 mm.     

Is Transesophageal Echocardiography Necessary before D.C. Cardioversion in Patients with a Normal Transthoracic Echocardiogram?

PURPOSE: Transesophageal echocardiography has emerged as an accepted approach before D.C. cardioversion for atrial fibrillation. The frequency of atrial thrombi detected on transesophageal echocardiography has varied from 7% to 23%. Many patients undergoing transesophageal echocardiography have had a previous transthoracic echocardiogram. Though transthoracic echocardiography has a low yield for the detection of intracardiac thrombi, it is highly accurate in diagnosing a structurally abnormal heart. The purpose of this study was to assess the frequency of thrombi detected by transesophageal echocardiography in patients with an entirely normal transthoracic echocardiogram and hence the advocacy of a selective approach in performing transesophageal echocardiography in patients undergoing D.C. cardioversion for atrial fibrillation. METHODS: 112 consecutive patients with atrial fibrillation who had undergone transesophageal echocardiography before D.C. cardioversion were evaluated. They all had a transthoracic echocardiogram within the 2 months preceding their transesophageal echocardiogram. Based on their transthoracic echocardiographic study, they were divided into two groups: Group 1 consisted of patients with a normal transthoracic echocardiogram and Group 2, those with an abnormal study. RESULTS: Thrombi or spontaneous echo contrast were found in 14 of 112 patients (16%). All however were detected in Group 2 patients. There was no patient with a normal transthoracic echocardiogram who had thrombus on his/her transesophageal echocardiogram. CONCLUSIONS: Our results suggest that a selective approach may be exercised in the use of transesophageal echocardiography prior to D.C. cardioversion for atrial fibrillation. Patients with an entirely "normal" transthoracic echocardiogram may proceed directly to cardioversion without a precardioversion transesophageal echocardiogram.     

The value of transesophageal echocardiography in predicting immediate and long-term outcome of balloon mitral valvuloplasty: comparison with transthoracic echocardiography

The purpose of this study was to assess the role of transesophageal echocardiography in predicting the immediate and long-term outcome of balloon mitral valvuloplasty, and compare the results to transthoracic echocardiography. BACKGROUND: Transesophageal echocardiography accurately detects left atrial thrombi and allows better visualization of mitral valve morphology; however, its value in predicting the immediate and long-term outcome of balloon mitral valvuloplasty had not been assessed as adequately as for transthoracic echocardiography. METHODS: In 56 patients referred for balloon mitral valvuloplasty, both transesophageal and transthoracic echocardiography were performed (Group A). An echo score for both techniques was used to reflect mitral valve morphology, and its predictive value for immediate and long-term outcome of the valvuloplasty was assessed. The impact of transesophageal echocardiography in preventing procedural embolic events in those 56 patients was assessed by comparison to another group of 41 patients, who were examined only by transthoracic echocardiography prior to balloon mitral valvuloplasty (Group B). RESULTS: In Group A, transesophageal echocardiography detected left atrial thrombus in seven, while transthoracic echocardiography detected left atrial thrombus in two patients. After 2 months of warfarin therapy, a repeat transesophageal echo examination in four patients showed resolution of thrombus in three who went on to have balloon mitral valvuloplasty. Among the 52 patients who eventually had the procedure after thrombus was excluded by transesophageal echocardiography, there were no embolic events, compared to three embolic events among the 41 patients in Group B (P = 0.08). The transthoracic echocardiography scores, while slightly higher, correlated well with transesophageal echocardiography scores (r = 0.51, P < 0.001). The increase in mitral valve area did not correlate well to total transthoracic or transesophageal echocardiography scores, while it correlated negatively to valve calcification by transthoracic (r = -0.29, P < 0.05) and mobility by transesophageal echocardiography (r = -0.59, P < 0.02). At follow-up (7 +/- 4 months) nonsurvivors (7/56) had higher total scores by either transthoracic (P < 0.01) or transesophageal echocardiography (P < 0.05) compared to survivors. The percent reduction in mitral valve area was greater with age (r = 0.5, P < 0.02), time to follow-up (r = 0.67, P < 0.002), valve mobility by transthoracic echocardiography (r = 0.59, P < 0.01), and valve calcification by transthoracic echocardiography (r = 0.37, P = 0.09) and transesophageal echocardiography (r = 0.4, P = 0.07). CONCLUSIONS: Transesophageal echocardiography is superior to transthoracic echocardiography in detecting left atrial thrombi, and it may reduce the risk of embolic events following balloon mitral valvuloplasty. Assessment of mitral valve morphology by transesophageal echocardiography is complementary and not superior to assessment by transthoracic echocardiography. Mitral valve calcification and mobility appear to be the best morphological predictors of immediate and long-term outcome following balloon mitral valvuloplasty.     

Simultaneous transesophageal atrial pacing and transesophageal two-dimensional echocardiography: a new method of stress echocardiography

The diagnostic use of exercise echocardiography has been widely reported. However, transthoracic exercise echocardiography is inadequate in up to 20% of patients because of poor image quality related to exercise. In an attempt to overcome these limitations, a system was developed in which transesophageal echocardiography is combined with simultaneous transesophageal atrial pacing by means of the same probe. In a prospective study, transesophageal echocardiography was performed before, during and immediately after maximal atrial pacing in 50 patients with suspected coronary artery disease. Results of transesophageal stress echocardiography were considered abnormal when new pacing-induced regional wall motion abnormalities were observed. Correlative routine bicycle exercise testing was carried out in 44 patients. Cardiac catheterization was performed in all patients. The success rate in obtaining high quality diagnostic images was 100% by transesophageal echocardiography. All nine patients without angiographic evidence of coronary artery disease had a normal result on the transesophageal stress echocardiogram (100% specificity). Thirty-eight of 41 patients with coronary artery disease (defined as greater than or equal to 50% luminal diameter narrowing of at least one major vessel) had an abnormal result on the transesophageal stress echocardiogram (93% sensitivity). The sensitivity of the technique for one, two or three vessel disease was 85%, 100% and 100%, respectively, compared with 44%, 50% and 83%, respectively, for bicycle exercise testing; the 12 lead electrocardiogram (ECG) during rapid atrial pacing showed a sensitivity of 25%, 64% and 86%, respectively. Thus, rapid atrial pacing combined with simultaneous transesophageal echocardiography is a highly specific and sensitive technique for the detection of coronary artery disease. Ischemia-induced wall motion abnormalities were detected earlier than observed ECG changes. The technique appears to be particularly suited to patients who are unable to perform an active stress test or those with poor quality transthoracic echocardiograms.     

Transesophageal echocardiography in critically ill patients

The feasibility, safety and clinical impact of transesophageal echocardiography were evaluated in 51 critically ill intensive care unit patients (28 men and 23 women; mean age 63 years) in whom transthoracic echocardiography was inadequate. At the time of transesophageal echocardiography, 30 patients (59%) were being mechanically ventilated. Transesophageal echocardiography was performed without significant complications in 49 patients (96%), and 2 patients with heart failure had worsening of hemodynamic and respiratory difficulties after insertion of the transesophageal probe. The most frequent indication, in 25 patients (49%), was unexplained hemodynamic instability. Other indications included evaluation of mitral regurgitation severity, prosthetic valvular dysfunction, endocarditis, aortic dissection and potential donor heart. In 30 patients (59%), transesophageal echocardiography identified cardiovascular problems that could not be clearly diagnosed by transthoracic echocardiography. In the remaining patients, transesophageal echocardiography permitted confident exclusion of suspected abnormalities because of its superior imaging qualities. Cardiac surgery was prompted by transesophageal echocardiographic findings in 12 patients (24%) and these findings were confirmed at operation in all. Therefore, transesophageal echocardiography can be safely performed and has a definite role in the diagnosis and expeditious management of critically ill cardiovascular patients.     

Diagnosis of main-stem pulmonary thromboemboli by transesophageal echocardiography

The aim of this report is to describe the usefulness of transesophageal echocardiography in the diagnosis of pulmonary emboli. A biplane transesophageal probe was used to examine the pulmonary artery in multiple views in three patients with suspected pulmonary emboli. The diagnosis of pulmonary emboli was made by transesophageal echocardiography in each of three patients when an echodense, circular or linear mass was seen in more than one view of the main or right pulmonary artery. In conclusion, our findings, coupled with previous case reports, suggest that transesophageal echocardiography should be considered in all critically ill patients with suspected pulmonary emboli.     

Transesophageal echocardiography in adults with a continuous precordial murmur.

In order to assess the ability of echocardiography in the detection of intracardiac and extracardiac shunts, we studied 11 patients (aged 22-64 yr) with a continuous precordial murmur using transthoracic and transesophageal echocardiography, and correlated the results with the subsequent angiographic and surgical findings. We found that only in 5 of 6 patients with a patent arterial duct could the continuous flow pattern be detected in pulmonary artery using transthoracic echocardiography, whereas it could be readily and accurately identified by transesophageal echocardiography in all patients. The diameters of the patent arterial duct were also measured and found to be in good correlation with subsequent surgical findings (r = 0.98, p less than 0.05). In 2 patients with a ruptured aneurysm of sinus of Valsalva which originated from the right coronary sinus and perforated into the right ventricle, transesophageal echocardiography gave a better image than transthoracic echocardiography. In 2 patients with coronary artery fistula, the origin and site of drainage of the coronary artery could be imaged using transesophageal echocardiography, but the course of coronary artery fistula was more easily detected by transthoracic echocardiography. In one patient with aortopulmonary window, the defect between ascending aorta and main pulmonary artery could readily be imaged by transesophageal echocardiography. We therefore recommend transesophageal echocardiography when evaluating patients with precordial continuous murmur in whom intracardiac and extracardiac shunts or defects are suspected.     

Effect of performing real time three-dimensional transesophageal echocardiography in addition to two-dimensional transesophageal echocardiography on operator diagnostic confidence

Background: This study evaluates the effects of performing real time three‐dimensional transesophageal echocardiography in addition to conventional two‐dimensional transesophageal echocardiography on diagnostic confidence. Methods: Operator diagnostic confidence in addressing clinical questions posed by the referral was scored using a five‐point scale for two‐dimensional transesophageal echocardiography alone and the combination of two‐dimensional and real time three‐dimensional transesophageal echocardiography in 136 consecutive patients undergoing examination in an academic hospital. Results: Mean diagnostic confidence score was higher for the combined studies compared to two‐dimensional transesophageal echocardiography alone (4.5 vs. 4.1, P < 0.001)). The addition of real time three‐dimensional transesophageal echocardiography increased diagnostic confidence score in 45 (33.1%) patients, and the percentage of studies with total diagnostic confidence rose from 40.4% with two‐dimensional transesophageal echocardiography alone to 65.4% after performing real time three‐dimensional transesophageal echocardiography. Type of clinical indication was associated with improved score by the combined exams (P < 0.004). The addition of real time three‐dimensional transesophageal echocardiography was most likely to improve diagnostic confidence score in studies performed to assess valve disease (56.1%) and least likely in examinations performed for intracardiac infection (14.9%). The location (anterior or posterior) of the primary cardiac pathology was not associated with improved score by the combined studies (P = 0.498). Conclusions: The addition of real time three‐dimensional transesophageal echocardiography to two‐dimensional transesophageal echocardiography increases diagnostic confidence in examinations routinely performed in an academic practice. Further studies of the impact of real time three‐dimensional transesophageal echocardiography on patient management, outcomes and displacement of or need for downstream testing are warranted. (Echocardiography 2011;28:235‐242)     

Diagnosis of noninfective cardiac mass lesions by two-dimensional echocardiography. Comparison of the transthoracic and transesophageal approaches

This study was conducted in 46 patients with cardiac thrombi, 15 patients with atrial myxomas, and 32 patients with other cardiac or paracardiac tumors. Diagnoses were subsequently proven by surgery, autopsy, computed tomography, magnetic resonance imaging, or angiography in all patients. All patients underwent precordial and transesophageal two-dimensional echocardiography to assess the various mass detection rates. Atrial myxomas and predominantly left-sided cardiac tumors were identified by both echocardiographic techniques with comparable detection rates. Left ventricular apical thrombi were detected more frequently by precordial echocardiography. In contrast, transesophageal echocardiography was superior in visualizing left atrial appendage thrombi, small and flat thrombi in the left atrial cavity, thrombi and tumors in the superior vena cava, and masses attached to the right heart and the descending thoracic aorta. These data indicate that transesophageal echocardiography leads to a clinically relevant improvement of the diagnostic potential in patients in whom cardiac masses are suspected or have to be excluded in order to ensure the safety of clinical procedures.     

Comparative value of transthoracic and transesophageal echocardiography in the assessment of congenital abnormalities of the atrioventricular junction

Information obtained from transthoracic and transesophageal echocardiography (two-dimensional echocardiography with spectral Doppler and color flow imaging) was compared in 17 patients with major congenital abnormalities of the atrioventricular (AV) junction (10 discordant AV connections, 1 criss-cross connection, 5 absent right connections and 1 absent left connection). The findings by either technique were correlated with findings at cardiac catheterization (12 patients) and at surgery (5 patients). In two of six patients with an absent AV connection as defined by transthoracic echocardiography, transesophageal imaging demonstrated an imperforate AV valve. In 11 of 11 patients with a discordant or criss-cross connection, assessment of AV valve and ventricular morphology (by defining the chordal attachments of both AV valves) was possible with transesophageal echocardiography (3 of 11 patients by transthoracic echocardiography); chordal straddling was detected in 1 patient and excluded in 3 others with an associated inlet ventricular septal defect. Anomalous pulmonary venous connection (one patient), atrial septal defect (three patients) and subpulmonary stenosis (five patients) were better assessed by transesophageal imaging, and atrial appendage morphology could be demonstrated in all. The transesophageal technique was less useful in demonstrating the anterior subaortic infundibulum or aortopulmonary shunt (two patients). Although systemic ventricular function could be assessed by either method with use of short-axis M-mode scans, transesophageal pulsed Doppler interrogation of AV valve and pulmonary venous flow patterns provided clues to diastolic dysfunction of the systemic ventricle.     

Current incidence of peripheral arterial embolism and role of echocardiography

We reviewed the incidence and outcome of all cases of upper and lower limb embolism surgically treated in our vascular unit, from January 2001 to June 2006, to assess the role of transthoracic and transesophageal echocardiography in defining the source of the embolus. Transthoracic echocardiography was carried out postoperatively, and patients in whom the embolic source was not found underwent transesophageal echocardiography. There were 85 patients (mean age, 69 years) who underwent embolectomy: 58 for lower and 27 for upper limb ischemia. The source or potential source of thrombus was demonstrated in 17 (20%) patients after transthoracic echocardiography. Fifty-three patients had transesophageal echocardiography, the source of embolism was found in 85%, and the subsequent management was changed in 47% of them. Arterial limb emboli are still prevalent in developing countries. Transthoracic echocardiography is a good screening tool for detecting a potential cardiac source of peripheral embolism, with transesophageal echocardiography being reserved for specific indications.     

Transthoracic echocardiography versus transesophageal echocardiography in detecting cardiac sources of embolism

Although the yield of potential cardiac sources of embolism by echocardiography in patients with stroke and arterial embolism has been low, with the advent of transesophageal echocardiography, a renewed enthusiasm for echocardiography in these patients has developed. This article reviews the six major studies comparing transthoracic to transesophageal echocardiography in the search for potential cardiac sources of embolism. The overall yield of transesophageal echocardiography in these studies for potential cardiac sources of embolism is 43% compared to 14% by transthoracic echocardiography in a total of 367 patients. In patients without clinical cardiac disease, the yield is lower but still substantially higher by transesophageal echocardiography (24% compared to 7% by transthoracic echocardiography). For left atrial thrombus, left atrial spontaneous contrast, patent foreman ovale, and atrial septal aneurysm (ASA), transesophageal echocardiography is clearly superior than transthoracic echocardiography. Data on the detection of mitral valve prolapse and left ventricular thrombus are conflicting and neither method is clearly superior. In addition, transesophageal echocardiography identifies certain abnormalities including debris in the aorta and prosthetic strands that transthoracic echocardiography is incapable of identifying. Although transthoracic echocardiography should continue to be the initial screening modality for stroke patients, transesophageal echocardiography should be performed when surface findings are negative or equivocal in patients with likely cardioembolic stroke.