Role of transoesophageal echocardiography in evaluation of cardiogenic embolism.

OBJECTIVE--To determine the value of transoesophageal echocardiography in the assessment of selected patients at risk of cardiogenic embolism or after it. DESIGN--Prospective comparison of the results of transoesophageal and transthoracic echocardiography. Transoesophageal echocardiography was performed with a 5 MHz single plane phased array transducer. SETTING--University teaching hospital. PATIENTS--100 patients referred for transoesophageal echocardiography after a cerebral ischaemic event or peripheral arterial embolism (n = 63), before percutaneous balloon dilatation of the mitral valve (n = 23), or before electrical cardioversion of atrial fibrillation (n = 14). RESULTS--Transthoracic echocardiography showed potential sources of embolism in four patients including left ventricular thrombus in two patients (with one false positive), left atrial appendage thrombus (n = 1), and patent foramen ovale (n = 1). Transoesophageal echocardiography showed 59 potential embolic sources in 45 patients including left atrial spontaneous echo contrast (n = 33), left atrial appendage thrombus (n = 13), left ventricular thrombus (n = 5), patent foramen ovale (n = 3), left ventricular spontaneous echo contrast (n = 2), mitral valve prosthesis thrombus (n = 1), mitral valve prolapse (n = 1), and pronounced aortic atheroma (n = 1). Transoesophagal echocardiography showed potential embolic sources in 36/53 (68%) patients with atrial fibrillation compared with 9/47 (19%) patients in sinus rhythm. Percutaneous balloon dilatation of the mitral valve was performed without embolic complications in 18 patients without left atrial thrombi and in three patients with small fixed thrombi in the left atrial appendage. It was cancelled in two patients with large thrombi in the left atrial appendage. Cardioversion was performed without embolic complications in 14 patients without left atrial thrombi. CONCLUSIONS--Transoesophageal echocardiography detects potential sources of embolism better than transthoracic echocardiography in selected patients at risk of cardiogenic embolism or after it.     

Role of transoesophageal echocardiography in evaluation of cardiogenic embolism.

OBJECTIVE--To determine the value of transoesophageal echocardiography in the assessment of selected patients at risk of cardiogenic embolism or after it. DESIGN--Prospective comparison of the results of transoesophageal and transthoracic echocardiography. Transoesophageal echocardiography was performed with a 5 MHz single plane phased array transducer. SETTING--University teaching hospital. PATIENTS--100 patients referred for transoesophageal echocardiography after a cerebral ischaemic event or peripheral arterial embolism (n = 63), before percutaneous balloon dilatation of the mitral valve (n = 23), or before electrical cardioversion of atrial fibrillation (n = 14). RESULTS--Transthoracic echocardiography showed potential sources of embolism in four patients including left ventricular thrombus in two patients (with one false positive), left atrial appendage thrombus (n = 1), and patent foramen ovale (n = 1). Transoesophageal echocardiography showed 59 potential embolic sources in 45 patients including left atrial spontaneous echo contrast (n = 33), left atrial appendage thrombus (n = 13), left ventricular thrombus (n = 5), patent foramen ovale (n = 3), left ventricular spontaneous echo contrast (n = 2), mitral valve prosthesis thrombus (n = 1), mitral valve prolapse (n = 1), and pronounced aortic atheroma (n = 1). Transoesophagal echocardiography showed potential embolic sources in 36/53 (68%) patients with atrial fibrillation compared with 9/47 (19%) patients in sinus rhythm. Percutaneous balloon dilatation of the mitral valve was performed without embolic complications in 18 patients without left atrial thrombi and in three patients with small fixed thrombi in the left atrial appendage. It was cancelled in two patients with large thrombi in the left atrial appendage. Cardioversion was performed without embolic complications in 14 patients without left atrial thrombi. CONCLUSIONS--Transoesophageal echocardiography detects potential sources of embolism better than transthoracic echocardiography in selected patients at risk of cardiogenic embolism or after it.     

The clinical role of transoesophageal echocardiography

The role of transoesophageal echocardiography (TEE) was evaluated in a consecutive series of 100 procedures performed in 86 patients (age 17–81, mean 56 years). All patients had prior transthoracic echocardiography (TTE). TEE was performed with a 5 MHz phased array transoesophageal transducer with pulsed wave Doppler and colour flow mapping capability. Forty-four per cent of patients received intravenous sedation and 36% received antibiotic prophylaxis. There were no complications of TEE. The TTE and TEE findings were compared. In patients referred for possible cardiac source of embolism, left atrial thrombi were detected in 8/27 TEE studies but in none of 27 TTE studies. In 12 patients with prosthetic valve dysfunction TEE distinguished prosthetic from periprosthetic regurgitation in 9/12 studies compared to 3/12 with TTE. In 11 patients with suspected aortic dissection TEE correctly detected dissection in all seven cases in which the diagnosis was subsequently confirmed, whereas TTE showed only equivocal findings in two cases. Vegetations were detected by TEE in 4/5 studies in patients with proven native valve endocarditis and by TTEin 2/5. No vegetations were detected by TTE or TEE in five studies in patients with proven prosthetic valve endocarditis. Compared with other investigations there were no false positive TEE studies and one possible false negative study. We conclude that TEE is a safeprocedure which often provides additional clinical information to transthoracic echocardiography.     

Clinical utility of transoesophageal echocardiography--preliminary experience of 100 cases.

We performed transoesophageal echocardiography (TEE) and compared its results with transthoracic echocardiographic (TTE) studies in a consecutive series of 100 cases. TEE was performed with a 5 MHz transducer with pulsed wave, continuous wave and colour Doppler facilities. All the patients were in unsedated state; the initial 50 were, in addition, monitored noninvasively for any change in heart rate, blood pressure or arterial oxygen saturation. The procedure was well tolerated by all; one patient had transient ventricular bigeminy. Except increase in heart rate and systolic blood pressure at the time of insertion of probe, there was no change in any of the clinical parameters studied. In patients of mitral stenosis, a thrombus in left atrium (LA) or left atrial appendage (LAA) was seen in 7/52 TEE studies, as compared to 4/52 TTE studies. LAA thrombi (2 cases) were detected only on TEE. Following balloon mitral valvuloplasty, a small atrial septal defect was seen in 6/8 TEE, but only 2/8 TTE studies. In 20 cases with doubtful atrial septal defects on TTE, TEE revealed an intact septum in 6 and delineated the anatomy of the defect in the remaining 14. TEE facilitated detection and better visualisation of paravalvular regurgitation in 4 cases with mitral and 3 cases with aortic valve prosthesis. In addition, TEE helped in excluding vegetations in 3 suspected cases of infective endocarditis and in studying details of 2 intracardiac masses. We conclude, TEE can be safely performed in conscious unsedated patients and provides valuable information in addition to transthoracic echocardiography.     

The increasing role of transesophageal echocardiography in unexplained cerebral ischemia

Cerebrovascular disease is a leading cause of morbidity and mortality in the United States. A significant number of cerebral infarctions are due to a cardiac source of embolus. Transesophageal echocardiography (TEE) is being used with increasing frequency to study patients with potential cardiac causes of cerebral ischemia. TEE has a higher sensitivity for detecting left atrial and left atrial appendage thrombi and for visualizing abnormalities of the atrial septum such as patent foramen ovale and aneurysm. Abnormalities of the aorta and native and prosthetic valves can now be clearly identified by TEE. Preliminary data suggest that TEE may influence clinical management in patients with unexplained stroke.     

An unusual case of infective endocarditis: Extension of a tricuspid valve vegetation into the left atrium through a patent foramen ovale

Tricuspid valve endocarditis frequently occurs in the setting of intravenous drug use. A case of tricuspid valve endocarditis in a 37-year-old woman with a history of intravenous cocaine use is described. Transthoracic echocardiography showed extension of the tricuspid valve mass through a patent foramen ovale and into the left atrium. One week after intravenous antibiotic treatment, the mass no longer traversed the patent foramen ovale, and only two smaller tricuspid valve vegetations remained. The present case demonstrates the value of performing a complete and thorough transthoracic echocardiography to visualize and evaluate both the right-and left-sided consequences of infective endocarditis in intravenous drug users. It also serves as a useful reminder to physicians caring for such patients that right-sided endocarditis can have important left-sided complications.     

Limitations of transoesophageal echocardiography in patients with focal cerebral ischaemic events.

OBJECTIVE--To investigate the detection rate of cardiac sources of embolism by transoesophageal echocardiography in patients with focal cerebral ischaemic events and to relate the echocardiographic findings to other clinical findings. DESIGN--Prospective study with blinded analysis of the echocardiographic data and subsequent comparison with the other clinical findings. SETTING--Regional cardiothoracic unit based in a teaching hospital. PATIENTS--131 consecutive patients with focal ischaemic cerebral events (49 with a transient ischaemic attack, 77 with a cerebrovascular accident, and five with a retinal arterial embolus) referred for echocardiography. INTERVENTIONS--Full M mode, cross sectional, Doppler, and contrast echocardiography by both the precordial and transoesophageal techniques. RESULTS--Precordial echocardiography detected a cardiac abnormality in 72 patients. Transoesophageal echocardiography confirmed all the precordial findings (except left ventricular hypertrophy, which at present cannot be defined with this technique) and detected other abnormalities in a further 20 patients (18 with potential right-to-left shunts and two with valve vegetations). It also showed spontaneous contrast echoes in 27 of 28 patients with a large left atrium and showed atrial thrombus in three. Cardiac abnormalities were clinically detected in 53 patients, all of which were confirmed or documented by echocardiography. In the 78 patients with no clinically detectable cardiac abnormality six had mitral valve prolapse and one had a regional wall motion defect (identified by precordial echocardiography) and 17 had potential right-to-left shunts (11 of which were identified only by transoesophageal echocardiography). CONCLUSIONS--Transoesophageal echocardiography is more sensitive than precordial echocardiography in detecting potential sources of embolism in these patients. However, except for the detection of a potential right-to-left shunt, the yield in patients with no cardiac abnormality is low. Moreover, the abnormalities detected in those with previously detected cardiac disease merely confirm the clinical diagnosis. Patients with left atrial spontaneous contrast echoes may benefit from anticoagulation but this requires further study. Until more data are available on this feature and on the role of potential right-to-left shunts in this population, the contribution of echocardiography, precordial or transoesophageal, remains limited.     

Limitations of transoesophageal echocardiography in patients with focal cerebral ischaemic events.

OBJECTIVE--To investigate the detection rate of cardiac sources of embolism by transoesophageal echocardiography in patients with focal cerebral ischaemic events and to relate the echocardiographic findings to other clinical findings. DESIGN--Prospective study with blinded analysis of the echocardiographic data and subsequent comparison with the other clinical findings. SETTING--Regional cardiothoracic unit based in a teaching hospital. PATIENTS--131 consecutive patients with focal ischaemic cerebral events (49 with a transient ischaemic attack, 77 with a cerebrovascular accident, and five with a retinal arterial embolus) referred for echocardiography. INTERVENTIONS--Full M mode, cross sectional, Doppler, and contrast echocardiography by both the precordial and transoesophageal techniques. RESULTS--Precordial echocardiography detected a cardiac abnormality in 72 patients. Transoesophageal echocardiography confirmed all the precordial findings (except left ventricular hypertrophy, which at present cannot be defined with this technique) and detected other abnormalities in a further 20 patients (18 with potential right-to-left shunts and two with valve vegetations). It also showed spontaneous contrast echoes in 27 of 28 patients with a large left atrium and showed atrial thrombus in three. Cardiac abnormalities were clinically detected in 53 patients, all of which were confirmed or documented by echocardiography. In the 78 patients with no clinically detectable cardiac abnormality six had mitral valve prolapse and one had a regional wall motion defect (identified by precordial echocardiography) and 17 had potential right-to-left shunts (11 of which were identified only by transoesophageal echocardiography). CONCLUSIONS--Transoesophageal echocardiography is more sensitive than precordial echocardiography in detecting potential sources of embolism in these patients. However, except for the detection of a potential right-to-left shunt, the yield in patients with no cardiac abnormality is low. Moreover, the abnormalities detected in those with previously detected cardiac disease merely confirm the clinical diagnosis. Patients with left atrial spontaneous contrast echoes may benefit from anticoagulation but this requires further study. Until more data are available on this feature and on the role of potential right-to-left shunts in this population, the contribution of echocardiography, precordial or transoesophageal, remains limited.     

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.     

The role of echocardiography in the management of the sources of embolism

The echocardiographic diagnosis of cardiac thrombi, vegetations and tumors as well as the identification of predisposing conditions such as patent foramen ovale, aortic atherosclerosis and other minor causes (e.g., mitral valve prolapse, mitral and aortic valve calcification) have crucial clinical relevance, affecting the choice of surgery and/or of pharmaceutical therapy in the setting of patients presenting embolism. The echocardiographic assessment helps not only for the retrospective diagnosis of sources of embolism but also for the prevention of events in asymptomatic patients. Echocardiography can also distinguish normal variants and artifacts from cardiac masses and tumors. Echocardiographic characterization/typology of cardiac sources of embolism is currently below par when compared with cardiac MRI, the current gold standard. Nevertheless, echocardiography remains the 'first-line' imaging tool, because of its low cost and the possibility to add easily available, functional and structural information at the patient's bedside.     

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)     

Features of patients with severe mitral stenosis with respect to atrial rhythm. Atrial fibrillation in predominant and tight mitral stenosis.

The aim of this study was to assess the features of patients with severe mitral stenosis in relation to atrial rhythm. Six hundred and fifty patients (pts) with severe mitral stenosis (MS) (valve area less than or equal to 1.5 cm2) who underwent percutaneous balloon commissurotomy (n = 600) or surgery (n = 50) were classified into 3 groups according to their atrial rhythm (AR): group A: sinus rhythm (SR) (n = 379), group B: SR with episodes of transient atrial fibrillation (AF) (n = 65), group C: permanent AF (n = 206). Uni- and multivariate analysis of clinical, echocardiographic and hemodynamic parameters with respect to the atrial rhythm was performed. Some parameters were comparable in all 3 groups: sex, pulmonary, right and left atrial pressures, mitral valve area, incidence of associated aortic valve disease. Nine parameters were different: mean age, NYHA class III or IV, previous commissurotomy, previous embolism, cardiac index, mitral regurgitation, tricuspid regurgitation, left atrium diameter, mitral calcification. Multivariate analysis, identified age, left atrial diameter and presence of mitral calcification as independent predictors of atrial fibrillation. Transoesophageal echocardiography was performed in 167 cases. A spontaneous echo contrast was recorded in 106 cases (63.5%) and was significantly correlated with a history of embolism and or left atrial thrombi detected by echocardiography. Atrial fibrillation, size of left atrium, severity of mitral stenosis and cardiac index were found to be independent predictive factors of spontaneous echo contrast.     

Utility of transesophageal echocardiography in identification of thrombogenic milieu in patients with atrial fibrillation (an ACUTE ancillary study)

The ACUTE trial randomly assigned patients who had atrial fibrillation (AF) of >2 days' duration to a transesophageal echocardiographically guided or a conventional strategy before cardioversion. In the 571 patients who underwent transesophageal echocardiography (TEE) in the ACUTE trial, we assessed the relative predictive value of baseline data derived by history, transthoracic echocardiography, and TEE for prediction of thrombus and adjudicated embolism (thromboembolism) as a composite end point. TEE was performed at 70 centers in 571 patients, 549 in the transesophageal echocardiographically guided group and 22 crossovers in the conventional group. Six patients (1.1%) who had embolism and 79 (13.8%) who had thrombi were identified in this group. Thrombus was completely resolved in 76.5% of patients who had repeat transesophageal echocardiographic procedures after 31.7 +/- 7.5 days of anticoagulation. For patients who had embolic events, none had a transesophageal echocardiographically identified thrombus; 5 of 6 (83.3%) had >/=1 transesophageal echocardiographic risk factors (including spontaneous echocardiographic contrast, aortic atheroma, patent foramen ovale, atrial septal aneurysm, mitral valve strands), and 4 of 6 (66.66%) had subtherapeutic anticoagulation or no anticoagulation. Clinical, transthoracic echocardiographic, and transesophageal echocardiographic risk factors contributed significantly to the prediction of composite thrombus/embolism. However, transesophageal echocardiographic thromboembolic risk factors were the strongest predictors of thromboembolism and provided statistically significant incremental value (chi-square 38.0, p <0.001) for identification of risk. Thus, in addition to thrombus identification, TEE has significant incremental value in the identification of patients who had high thromboembolic risk. In conclusion, this study supports the role of TEE and anticoagulation monitoring in patients who have atrial fibrillation and is useful for identifying thromboembolic risk factors.     

Occlusion by catheter intervention in patent foramen ovale via additional transseptal puncture

In patients with a cryptogenic cerebral ischemia, the percutaneous closure of a patent foramen ovale (PFO) has gained increasing acceptance as an alternative strategy to prevent paradoxical embolism. Promising data with low recurrence rates have been reported for several self-expanding double disk devices. The implantation of the device is usually performed by passing the PFO. However, in one patient with a TIA (m, 43 years) transesophageal echocardiography (TEE) revealed an atrial septum abnormality with a hypermobile septum and a very small distance (approximately 12 mm) between the PFO channel and the anterior mitral valve leaflet, which was too short to accommodate the regular implantation procedure of the device via the PFO-channel itself. In this particular case the device (PFO-Star TSD) was advanced to the left atrium via an additional transseptal puncture--performed under TEE guidance--to allow for complete closure of the PFO without impairment of the mitral valve function. No periinterventional complications were observed. During the follow-up period of 9 months the patient was completely asymptomatic with no functional impairment of the mitral valve and no residual intracardiac shunt.     

Value of transesophageal echocardiography. From a preliminary experience of 532 cases

Transesophageal echocardiography (TEE) was introduced recently in France. The aim of this study was to review the diagnostic value of this technique after 8 months' use in our cardiology department. A total of 532 TEE studies were carried out between April and December 1988 in 396 patients (average age 54 years, range 17 to 89 years) at Tenon Hospital. The failure rate was 1.8 per cent (N = 10), over half of which occurred at the beginning of the operator's experience. TEE was particularly valuable compared with the standard transthoracic approach in the following instances: the investigation of mitral stenosis, especially before percutaneous valvuloplasty (N = 75). A left atrial thrombus was demonstrated in 5 cases by TEE vs none by standard echocardiography. There was also a much higher diagnostic sensitivity for small interatrial shunts (40 vs 6) resulting from transseptal catheterisation. In the preoperative investigation of severe mitral regurgitation (N = 29). The etiology was accurately diagnosed in 29 vs 26 cases, and the mechanism of the regurgitation was correctly classified especially in cases of ruptured chordae (15 vs 6 cases). In endocarditis (N = 26) by the visualisation of abscess of the aortic ring (7 vs 1) and vegetations (19 vs 8). In prosthetic valve dysfunction (N = 65) by the demonstration of primary degeneration of bioprostheses (7 vs 4), perivalvular leaks (10 vs 4) and non-occlusive thrombi of mechanical prostheses (3 vs 0). In cases of intracardiac tumours, dissection of the thoracic aorta and atrial septal defects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Atrial septal aneurysm as a cardioembolic source in adult patients with stroke and normal carotid arteries. A multicentre study.

BACKGROUND: Atrial septal aneurysm has been considered a potential source of cardiogenic embolism for many years. The present study evaluated the prevalence and characteristics of atrial septal aneurysm in a patient population with stroke and normal carotid arteries compared to a control population without stroke. METHODS: A total of 606 patients were enrolled between November 1990 and December 1996. The study group included 245 patients who had experienced cerebral ischaemic attack but had normal carotid arteries. The control group included 316 age- and sex-matched patients undergoing transoesophageal echocardiography for indications other than a search for a cardiac source of embolism. The prevalence and morphological characteristics of atrial septal aneurysm were evaluated and compared.Results We reported a higher prevalence of atrial septal aneurysm in the group with cerebral ischaemia; 68 patients (27.7%) vs 36 patients (9.9%) from the control group; P<0.001. A patent foramen ovale was detected with contrast injection in 69.2% of the patients with atrial septal aneurysm. Atrial septal aneurysm predicted the presence of a patent foramen ovale (odds ratio of patent foramen ovale 4.2; 95% CI 1.03-9.8). Multivariate analysis showed that atrial septal aneurysm was an independent predictor of an embolic event. In the 95% of patients with atrial septal aneurysm and cerebral ischaemia aged less than 45 years, transoesophageal echocardiography did not detect a source of embolism other than an associated patent foramen ovale. CONCLUSIONS: The prevalence of atrial septal aneurysm in patients with cerebral ischaemia and normal carotid arteries was 27.7%, higher than the control group. Atrial septal aneurysm was frequently associated with patent foramen ovale. In patients less than 45 years old, atrial septal aneurysm was the only potential cardiac source of embolism detected with transoesophageal echocardiography.     

Etiology and pathogenesis of thromboembolism.

Thrombus formation in the left atrium and left ventricle is primarily due to stasis of blood which causes activation of the coagulation system. Migration of thrombotic material into the circulation depends on the dynamic forces of the circulation. Atrial fibrillation is the commonest underlying cardiac disorder predisposing to thromboembolism. Rheumatic mitral stenosis, left atrial enlargement, prior myocardial infarction, hypertension, and echocardiographic left ventricular hypertrophy are risk factors for thromboembolic stroke in elderly patients with chronic atrial fibrillation. Non-valvular atrial fibrillation accounts for 45% of cardiac sources of thromboembolic stroke and includes patients with ischemic heart disease, hypertension, thyrotoxic heart disease, hypertrophic cardiomyopathy, chronic sinoatrial disorder, and idiopathic atrial fibrillation. 15% of cardiac sources of thromboembolic stroke are associated with acute myocardial infarction, 10% with left ventricular aneurysm and mural thrombi remote from an acute myocardial infarction, 10% with rheumatic valvular heart disease, and 10% with prosthetic cardiac valves. Mitral valve prolapse, mitral annular calcium, nonischemic cardiomyopathies, infective endocarditis, nonbacterial thrombotic endocarditis, left atrial myxoma, paradoxical embolism associated with congenital heart disease, calcific aortic stenosis, and complex atherosclerotic plaque within the proximal aorta also contribute to thromboembolism.     

Location, size and morphological characteristics of left atrial thrombi as assessed by echocardiography in patients with rheumatic mitral valve disease.

AIMS: This study aimed to assess the use of transthoracic and transoesophageal echocardiography in diagnosing the thrombi located in the left atrium and/or left atrial appendage in patients with rheumatic mitral valve disease, and to investigate the characteristics of thrombi in comparison to intraoperative findings. METHODS AND RESULTS: The study group was comprised of 474 patients who underwent transthoracic and transoesophageal echocardiography prior to mitral valve surgery. Location, thickness and morphological characteristics of thrombi were determined by transoesophageal echocardiography. Intraoperative assessment disclosed left atrial thrombi in 105 patients. Thickness of thrombi < or = 1cm, and thrombi confined to left atrial appendage were associated with false-negative results by transthoracic echocardiography. However, diameter and morphological characteristics of thrombi, left atrial and left atrial appendage size, and the presence of the spontaneous echo contrast were not associated with the diagnosis of thrombi by transthoracic echocardiography. For overall left atrial thrombi, sensitivity and specificity of transthoracic echocardiography were 32%, and 94%, respectively. Sensitivity and specificity of transoesophageal echocardiography for thrombi in the left atrial appendage were 98%, and 98%, for thrombi in the main left atrial cavity were 81%, and 99%, and for thrombi located in both left atrium and appendage cavities were 100%, and 100%, respectively. CONCLUSION: In patients with rheumatic mitral valve disease, detection of left atrial thrombi by transthoracic echocardiography seems to be determined by thickness and location of thrombi. The multilobed structure of the left atrial appendage and artifacts over posterior wall of the left atrium may still prevent precise diagnosis even with transoesophageal echocardiography.     

Transesophageal echocardiography in the assessment of patients presenting with ischemic cerebral events without previous evidence of a cardiac source of emboli.

Transesophageal echocardiography (TEE) is accepted as a valuable tool in the evaluation of ischemic stroke patients, particularly in the young and in cases of unknown cause. However, the real clinical impact of additional TEE data remains to be defined. PURPOSE: The aim of this study was to present our experience with TEE in ischemic stroke patients without previous evidence of a cardiac source of emboli. METHODS: From March 1991 to June 2000 we studied 172 patients (80 males, 92 females, mean age 43 +/- 12 years presenting with a transient ischemic attack or a recent cerebral infarction who had no previous evidence by clinical assessment, electrocardiogram and transthoracic echocardiography of a cardiac of emboli source. The population was divided into two groups: Group A--age < or = 45 years, n = 101 (43 males, 58 females, mean age 34 +/- 7 years) and Group B--age > 45 years, n = 71 (36 males, 35 females, mean age 54 +/- 7 years). Information was gathered from clinical records. In every case TEE included Doppler color flow imaging and multiple contrast injections (agitated saline) with and without Valsalva maneuver. RESULTS: A potential cardiac of emboli source was found in 29% of the patients, with a higher prevalence in the older group (group A--25%, Group B--35%, ns). Atrial septal abnormalities accounted for most of the detected findings (23 patent foramen ovale, 17 atrial septal aneurysms and two atrial septal defects, representing altogether 71% of the findings). The other detected anomalies were distributed as follows: aortic plaques--six, mitral valve prolapse--five vegetations--four, thrombus in left atrial appendage--two. Only six patients (3.5%) had abnormalities which in themselves determined a specific approach, which were found mostly in the older group (Group A--two vegetations; Group B--two vegetations, two thrombi). CONCLUSIONS: TEE identified additional findings with possible embolic potential in a considerable number of cases, the majority of which were of a debatable cause-effect relation. A higher diagnostic yield and clinical relevance was found in older patients, which argues against age being used as a selective criterion for it. Our experience suggests that routine TEE in this setting is of questionable value and has little impact on clinical management, for which reason TEE referral should be decided on an individual patient basis.     

Echocardiography in diagnostic assessment of peripheral arterial embolization

In an attempt to identify a cardiac source of emboli, two-dimensional echocardiography was performed postoperatively in 42 consecutive patients with acute peripheral arterial embolism requiring urgent embolectomy. The patients were divided into four groups. Group 1 included 14 patients with chronic atrial fibrillation, among whom four cases of intracavitary thrombi were detected. Group 2 included 13 patients with acute or previous myocardial infarction, and left ventricular thrombi were detected in three. Group 3 included one patient with a prosthetic mechanical aortic valve and one with mitral valve prolapse; thrombi were not detected in either. Group 4 comprised 13 patients with no clinical evidence of a cardiac source of embolism; in one of them a large left ventricular thrombus was detected. Altogether eight intracavitary thrombi were detected (19%), and only in three (7.1%) were the results of echocardiographic examinations defined as entirely normal. A number of clinically undetected cardiac lesions, such as mitral annular calcification and aortic valve calcification, possibly associated with peripheral arterial embolism, were also detected by postoperative echocardiography. Because of the high percentage of intracavitary thrombi detected and the therapeutic implications thereof, especially if embolism recurred, it is concluded that two-dimensional echocardiographic examination should be recommended for patients with acute peripheral embolism.