In vivo magnetic resonance imaging and surgical histopathology of intracardiac masses: distinct features of subacute thrombi

We evaluated intracardiac masses in vivo, in situ and histologically to determine tissue properties revealed by magnetic resonance (MR) imaging. In 15 consecutive patients scheduled for cardiotomy, the cardiac chambers were studied preoperatively with MR imaging and echocardiography. Visual examination of one or more chambers was performed during cardiotomy for mitral valve replacement, aneurysmectomy, atrial septal repair and atriotomy. Six thrombi (1 atrial appendage, 5 ventricular) and 2 atrial myxomas were removed and subjected to histological analysis. All masses were detected preoperatively by MR imaging. The smallest was a subacute 3-mm mural clot in the left ventricle and was undetected by transesophageal and transthoracic echocardiography. The 3 subacute clots had homogeneously low MR signals, did not enhance with gadolinium and exhibited magnetic susceptibility effects; histopathology confirmed these clots to be avascular and laden with dense iron deposition related to hemoglobin breakdown products. The 3 organized clots had intermediate and heterogeneous MR signals and multiple areas of gadolinium enhancement. The 2 myxomas had low MR signals and gadolinium enhancement in the core and septal attachment; these areas had dense neovascular channels. Subacute thrombi appear to have MR features that are distinct from organized thrombi and myxomas, and MR images of subacute thrombi contrast sharply with normal cardiac structures, enabling detection of thin mural clots that may be echographically occult. These findings may be of value, because a subacute clot may be more likely than an organized thrombus to give rise to an embolus.     

Role of transesophageal echocardiography in percutaneous balloon mitral valvuloplasty

Echocardiography is useful in the selection of patients for percutaneous balloon mitral valvuloplasty, which is an effective treatment in suitable patients with rheumatic mitral stenosis. Transesophageal echocardiography appears superior to precordial echocardiography in this role because transesophageal echocardiography is not only reliable in the assessment of mitral valvular morphology but also more sensitive in the detection of left atrial thrombi and mitral regurgitation. Transesophageal echocardiography can be used in guiding the proper positioning of the catheters during the dilatation procedure. Complications of balloon mitral valvuloplasty such as torn mitral leaflets or atrial septal defects can also be diagnosed reliably by transesophageal echocardiography. Thus, transesophageal echocardiography should be an integral part of balloon mitral valvuloplasty.     

Clinical significance of perfusion imaging of the left atrial wall and structures in its cavity by contrast echocardiography.

This study examined whether myocardial contrast echocardiography (MCE) can visualize left atrial appendage myocardial perfusion using transesophageal echocardiography (TEE) with intracoronary injection of sonicated albumin. We also evaluated blood flow into normal structures (i.e. muscular trabeculae) and abnormal masses (i.e. fresh thrombi and myxomas) within the left atrium by MCE. TEE images were obtained with a biplane or multiplane 5 MHz transducer in 16 patients without significant coronary artery occlusive disease. Left atrial appendage myocardium was divided into 4 segments in both the transverse and longitudinal planes, and contrast opacification of each segment during MCE was visually evaluated by 2 independent observers. Visual assessment of contrast opacification of prominent muscular trabeculae within the left atrial appendage (6 patients), and of left atrial or left atrial appendage thrombi (4 patients), was also performed. The ratio of background-subtracted peak videointensity from muscular trabeculae or thrombi versus left atrial appendage myocardium was determined as corrected peak videointensity. In 3 patients with myxomas, contrast opacification of the tumor was visually assessed. Ninety-six segments of left atrial appendage myocardium were visually analyzed. Contrast opacification of the left atrial appendage myocardium was identified in 92 of 96 segments (96%, 95% confidence interval 0.90-0.98) by Observer 1 and in 91 of 96 segments (95%, 95% confidence interval 0.88-0.98) by Observer 2. MCE also enhanced the imaging of left atrial appendage muscular trabeculae, but not of left atrial or left atrial appendage thrombi. Corrected peak videointensity from thrombi was significantly lower than that from muscular trabeculae (0.15 +/- 0.11 vs 0.95 +/- 0.18, p < 0.05). All myxomas were distinctly opacified by MCE. Transesophageal MCE with intracoronary injection of sonicated albumin can image left atrial appendage myocardial perfusion. MCE allows the evaluation of blood flow into normal structures and abnormal masses within the left atrium.     

Cardiological diagnosis in arterial embolism]

Potential cardiac sources of arterial embolism are in particular thrombi within the left atrium or ventricle, or attached to a prosthetic valve, intracardiac tumors, and vegetations due to endocarditis. Patent foramen ovale and atrial septal defect may lead to paradoxical embolism, and spontaneous echo contrast within the heart has to be considered as a parameter of increased thromboembolic risk. In rare cases, atrial septal aneurysm, mitral valve prolapse or annulus calcification and calcified aortic stenosis has to be taken into consideration. Current method of choice for diagnosis of these abnormalities is echocardiography. When the transthoracic approach fails, transesophageal echocardiography (TEE) leads to a definite diagnosis in most cases. Precordial echocardiography allows the detection of left ventricular thrombi with a sensitivity ranging between 72 and 95%, and monoplane TEE does usually not increase these numbers. In contrast, thrombi within the left atrium and particularly in the left atrial appendage can be detected with a significantly higher detection rate when TEE is used. The same is true for spontaneous echo contrast in the left atrium, a phenomenon which is almost exclusively diagnosed by TEE, as well as for endocarditis associated vegetations that can be identified by TEE with a sensitivity higher than 90%. Patient foramen ovale is usually diagnosed by precordial contrast echocardiography combined with a Valsalva maneuver; color Doppler or contrast TEE allows to increase the detection rate. In the diagnosis of prosthetic valve attached thrombi and vegetations, TEE is clearly superior compared to the precordial examination, at least concerning prosthetic devices in mitral position. If echocardiography fails to identify a potential cardiac source of embolism, other techniques don't add significant information in most cases. Detection of a potential source of embolism, however, does not necessarily prove that the particular finding represents the true etiology of an embolic event; results of all clinical and technical examinations have to be evaluated in a critical synopsis. In addition, proper therapeutic consequences in quite a number of abnormalities considered as potential cardiac sources of embolism are not yet defined.     

Atrial myxoma: case report and a review of the literature

Atrial myxomas are the most common benign primary tumor of the heart and occur in as many as 3 in 1000 patients. These tumors are a major cause of patient morbidity and mortality. Although the majority of atrial myxomas occur in the left atrium, 3 separate familial myxoma syndromes can result in multiple myxomas in atypical locations. Approximately 50% of patients with myxomas may experience symptoms due to central or peripheral embolism or intracardiac obstruction, but 10% of patients may be completely asymptomatic. Screening for myxomas should involve a thorough history and physical examination and a transthoracic and/or transesophageal echocardiogram. Transthoracic echocardiography is approximately 95% sensitive for the detection of cardiac myxomas, and transesophageal echocardiography approaches 100% sensitivity. Though the majority of atrial myxomas are sporadic, it is imperative that first-degree relatives of patients with documented myxomas undergo screening for occult myxomas. Surgical removal of the myxoma is the treatment of choice and usually curative; however, myxoma recurrence does occur and is most frequently associated with a familial syndrome.     

Transesophageal versus transthoracic echocardiography in the evaluation of right atrial tumors

The purpose of this study was to define the contribution of transesophageal echocardiography to the diagnosis of right atrial tumors in a large series of patients with this rare finding. Transesophageal echocardiography (TEE) has been found to be valuable in evaluating patients with intracardiac masses and has been shown ton be superior to transthoracic echocardiography (TTE) in evaluating left heart masses. Between 1989 and 1993, 23 patients with either known tumors elsewhere or right atrial masses that were detected on TTE were evaluated with TEE. TEE studies were performed in the noninvasive cardiology laboratory. All patients were studied with 5 MHz biplane or omniplane transducers. The right atrium was evaluated for the presence, characteristics, extent, and attachment of any masses and for extension of these masses into the great vessels or other cardiac chambers. No complications occurred. Six patients had primary right atrium tumors. In 10 patients the tumors reached the right atrium via the inferior vena cava. Seven patients had malignant secondary tumors. TEE demonstrated three tumors not detected by TTE. Furthermore TEE provided 16 additional findings not seen on TTE. In conclusion, TEE is superior to TTE in the evaluation of right atrial tumors. TEE should be considered in patients with right atrial tumors even when these tumors have been demonstrated with TTE.     

Diagnosis of abnormal intra-atrial echoes. Contribution of transesophageal echocardiography]

The aim of this study was to evaluate the results of transesophageal echocardiography in the diagnosis of abnormal intraatrial echoes detected by transthoracic echocardiography. Patients with active endocarditis, mitral stenosis, and valve prostheses were excluded. The 47 patients (28 women and 19 men) were classified into 4 groups according to the results of transesophageal echocardiography. Group I: normal (7 cases), "phantom echos"; Group II: anatomical variants (9 cases), Chiari apparatus, muscular spur; Group III: pseudo-tumours (7 cases); retro-atrial haematoma, mitral valve prolapse, interatrial septal aneurysm; Group IV: cardiac masses (24 cases). This group comprises: typical myxomas (10 cases), typical thrombi (2 cases), localised atypical masses, relatively immobile and non-prolapsing: 5 myxomas, 1 metastasis, 2 thrombi. The results of this study suggest that transesophageal echocardiography is very useful in diagnosing suspected abnormal intraatrial echos observed on conventional transthoracic examination. However, the nature of the mass may remain obscure.     

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.     

Use of echocardiography in detecting cardiac sources of embolus

Up to 20% of all ischemic strokes are felt to be the result of emboli from the heart. High resolution transthoracic (TTE) and transesophageal (TEE) echocardiography have been the principal diagnostic tools for detecting associated cardiac abnormalities and for guiding medical and surgical approaches to these patients. In addition to identifying the precise location and morphological characteristics of intracardiac masses, echocardiography has improved our ability to predict embolic potential of these masses. Specific cardiac lesions that are predisposed to stroke and are readily identifiable by echocardiography include: cardiac thrombi, valvular vegetations, cardiac tumors, aortic atheroma, atrial septal aneurysm, and regional left ventricular wall abnormalities. Careful interrogation of patients with cerebrovascular accidents has identified a potential cardiac source of embolus in approximately 30%. This is largely due to the advent of TEE, which has provided much better assessment of posterior cardiac chambers including left atrium and left atrial appendage. Use of TEE in identifying a cardiac source of embolus is indicated in patients with stroke who are young, have no apparent cerebrovascular disease, or have recurrent embolic events. Echocardiography is an essential diagnostic tool in evaluating patients with a suspected cardiac source of embolus. TTE and TEE provide invaluable information regarding the majority of cardiac sources of embolus.     

The role of transesophageal echocardiography in the detection of left atrial thrombi

Sensitivity of transthoracic echocardiography in the detection of left atrial thrombi, in particular thrombi confined to the left atrial appendage, is surprisingly low (33%-72%). Concerning the detection of left atrial thrombi, transthoracic echocardiography appears as an inadequate technique in patients with suspected cardiogenic embolism with a success rate of only 0.8% in earlier, and about 3% in recent studies. Imaging from the esophagus substantially increases the detection rate for left atrial thrombi, and is the only clinically relevant semiinvasive technique to diagnose thrombi confined to the left atrial appendage. Transesophageal echocardiography has markedly increased the diagnostic power of cardiovascular ultrasound in patients with suspected cardiogenic embolism and/or atrial fibrillation. Meta-analysis of pooled studies using the transesophageal approach in these patients revealed thrombi within the left atrial cavity in about 7% and within the atrial appendage in about 12% of cases.     

Recurrent myxoma implanted in the left atrial appendage

We present the case of a young woman who developed myxomas in multiple cardiac chambers for the third time. One of the tumors was found in the left atrial appendage with the use of transesophageal echocardiography, indicating that this technique is the method of choice for the follow-up of multiple myxomas.     

Imaging of intracardiac thrombus

Intracardiac thrombus is an important clinical condition because of its potential complications. Detection of ventricular thrombi is generally performed by transthoracic echocardiography while atrial thrombi are generally evaluated by transesophageal echocardiography. Contrast-enhanced computerized tomography is more sensitive for detecting ventricular and atrial thrombi than transthoracic echocardiography, but the technique has been demonstrated to be inferior to transesophageal echocardiography for displaying atrial thrombi. Cardiac magnetic resonance imaging provides superior specificity for evaluation of tissue characteristics and helps to differentiate thrombi from other masses.     

The echocardiographic spectrum of atrial myxoma: a ten-year experience

We analyzed the echocardiograms of 28 patients with a left atrial myxoma and two with a right atrial myxoma. Our purpose was to evaluate the value of echocardiography for the diagnosis of these cardiac masses. Only 59% of the m-mode echocardiograms in patients with a left atrial myxoma showed the characteristic findings of multiple diastolic echoes within the mitral orifice as well as abnormal systolic echoes within the left atrium. M-mode echocardiograms were atypical for left atrial myxoma in the remaining patients, and a definitive diagnosis could not be established on the basis of this procedure in six of the patients (22%). Two-dimensional echocardiography showed the presence of a left atrial mass in all 16 patients who had the procedure, and aided in understanding the atypical m-mode recordings. There was a close relationship (r =.82) between two-dimensional echocardiographic measurements of the myxomas' size and pathologic measurements. Both right atrial myxomas could be identified on the m-mode echocardiogram. Our experience indicates that two-dimensional echocardiography is superior to the m-mode technique for the diagnosis and characterization of left atrial myxomas.     

Comparative values of the precordial and transesophageal approaches in the echocardiographic evaluation of atrial baffle function after an atrial correction procedure

Previous methods used to assess atrial baffle function after correction of transposition of the great arteries have included precordial echocardiography and cardiac catheterization. To evaluate whether single plane transesophageal echocardiography might provide additional information, its findings were correlated with information derived from both precordial echocardiography and cardiac catheterization in 15 patients (14 Mustard procedures, 1 Senning procedure) aged 4.2 to 33 years (mean 16.3). Precordial ultrasound with combined imaging, color flow mapping and pulsed Doppler ultrasound visualized the supramitral portion of the common systemic venous atrium in every case but could identify only superior limb obstruction in three of six patients, mid-baffle obstruction in zero of two and inferior limb obstruction in zero of two patients. Transesophageal studies with use of the same range of ultrasound methods demonstrated superior limb obstruction (severe in four, mild in two) in six of six patients, mid-baffle obstruction in two of two and inferior limb obstruction in two of two patients. The entire pulmonary venous atrium was equally well interrogated by either ultrasound approach, with both identifying three cases (two mild, one moderate) of mid-pulmonary venous atrium obstruction. However, individual pulmonary vein velocity profiles could only be recorded by transesophageal pulsed Doppler ultrasound. Precordial studies identified baffle leaks (1 large, 2 small) in only three patients, whereas transesophageal studies identified 11 such baffle leaks (1 large, 10 small), which were multiple in two patients. It is concluded that transesophageal echocardiography provides a more detailed and accurate assessment of atrial baffle morphology and function than is provided by either precordial ultrasound or cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transesophageal contrast echocardiography and color flow mapping: methods of choice for the detection of shunts at the atrial level?

The detection of shunts at the atrial level is important, and a reliable means of diagnosis is required. Precordial contrast echocardiography is usually performed to detect such shunts. To investigate the advantages of transesophageal echocardiographic techniques, we studied 167 consecutive patients with both precordial and transesophageal echocardiography, using two-dimensional imaging with contrast techniques (with and without a Valsalva maneuver) and color flow mapping. A patent foramen ovale was diagnosed in 31 patients, an atrial septal defect in 11 (7 with bidirectional shunts), and a pulmonary arteriovenous fistula in 3 patients. All right-to-left shunts were detected with transesophageal contrast echocardiography. With these results used as the gold standard, the sensitivity of combined precordial techniques was 37% and that of transesophageal color flow mapping 46%. All left-to-right shunts were detected by transesophageal color flow mapping. With these results used as the gold standard, the sensitivities of both precordial color flow mapping and a transesophageal negative right atrial contrast study were 27%. We conclude that transesophageal contrast echocardiography is the echocardiographic method of choice for the detection of a right-to-left shunt at the atrial level, which cannot be excluded by negative results on precordial study or on transesophageal color flow map study. A left-to-right shunt at this level is best detected by transesophageal color flow mapping.     

Transesophageal echocardiography in the study of intracardiac thrombosis, tumors and vegetations]

Of 200 consecutive patients, studied with transesophageal echocardiography the findings were analyzed with respect to the presence of thrombi, tumors or vegetations. Thrombus formation was detected in 18 patients; their location and associated pathology are described. Tumors were present in 9 cases and in 10 patients endocarditis in native or prosthetic valves. The information obtained by transesophageal echocardiography was compared with transthoracic echocardiographic data. Transoesophageal echocardiography was demonstrated to be more sensitive, especially in the detection of intracavitary masses in the posterior structures of the heart.     

Concomitant lipomatous hypertrophy and left atrial mass: Distinguishing benign from malignant

Masses in and near the interatrial septum may be either benign or malignant. The most common mass near the interatrial septum is lipomatous atrial septal hypertrophy (LASH). LASH can be present in patients with intracardiac malignancies, myxomas, lipomas, or other cardiac masses. It is important to recognize the transesophageal echocardiography (TEE) characteristics of these pathologies to arrive at an accurate diagnosis with an appropriate plan for intraoperative resection. At the authors’ institution, patients have been referred for surgery due to a finding of significant LASH masquerading as a left atrial myxoma. In challenging cases, TEE offers a thorough evaluation of the interatrial septum to delineate between multiple intracardiac masses.     

Transesophageal echocardiography in the definition of intracardiac sources of emboli in patients with recent ischemic stroke

Using both transthoracic and transesophageal echocardiography we studied 13 consecutive patients with recent CT-proven ischemic stroke in which a carotid arteries high-resolution ultrasound study failed to detect thrombosis or other relevant atherosclerotic lesions in the pertinent arteries. The mean age was 53 years (range: 36-65). Two patients exhibited clinical signs of cardiac disease at physical examination i.e. absolute arrhythmia, mitral stenosis. Conventional transthoracic echocardiography allowed the detection of potential cardiac sources of emboli in 2/13 patients (15.4%): mitral stenosis in one patient and dilated cardiomyopathy in another. Transesophageal echocardiography was successfully performed without general sedation in all patients. Potential cardiac sources of emboli could be identified in 12/13 patients (92%). Left atrial thrombi were found in 3 patients: in two of them they were associated with rheumatic alterations of mitral valve leaflets; in the third patient a small thrombus was located inside a normal-sized, poorly contracting left atrial appendage. Left atrial appendage could be clearly visualized in all patients. A myxoid degeneration of a prolapsing mitral leaflet was found in 3 patients and an interatrial septum aneurysm in 2. Furthermore, at color-flow Doppler and contrast transesophageal echocardiography, 7 patients (54%) showed patency of the foramen ovale. In 5 of these patients paradoxical right to left shunting after cough or Valsalva manoeuvre could be evidenced. With reference to 11/13 patients with no clinical signs of cardiac disease at physical examination, subclinical potential cardiac sources of emboli could be detected at conventional transthoracic echocardiography in 1 and at transesophageal echocardiography in 10 patients (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Left atrial myxoma: new perspectives in the diagnosis of murmur free cases

No cardiological signs or symptoms were seen in three patients with left atrial myxomas. The diagnosis was established by cross sectional echocardiography. In two patients this investigation was performed to exclude a cardiac source of systemic emboli. The third patient had constitutional signs only. All three had raised erythrocyte sedimentation rates and C reactive protein concentrations. In two patients the myxomas were successfully excised; the third patient who had presented with massive peripheral and central embolisation died during emergency operation. Cross sectional echocardiography is the technique of choice for detecting atrial myxomas and the absence of the cardiological signs should not preclude referral for diagnostic echocardiography.     

Left atrial myxoma: new perspectives in the diagnosis of murmur free cases.

No cardiological signs or symptoms were seen in three patients with left atrial myxomas. The diagnosis was established by cross sectional echocardiography. In two patients this investigation was performed to exclude a cardiac source of systemic emboli. The third patient had constitutional signs only. All three had raised erythrocyte sedimentation rates and C reactive protein concentrations. In two patients the myxomas were successfully excised; the third patient who had presented with massive peripheral and central embolisation died during emergency operation. Cross sectional echocardiography is the technique of choice for detecting atrial myxomas and the absence of the cardiological signs should not preclude referral for diagnostic echocardiography.