Echocardiographic diagnosis of left ventricular thrombi

Left ventricular mural thrombus after acute myocardial infarction

Left ventricular mural thrombus is a well-recognized complication of acute myocardial infarction. In survivors of infarction, the incidence with which mural thrombus occurs is influenced by the location and magnitude of infarction, so that it occurs commonly in those with large anterior Q-wave infarctions, particularly in the presence of a left ventricular aneurysm. Echocardiography, radionuclide imaging with indium-111 labeled platelets, computerized tomography, and magnetic resonance imaging may be used to identify a left ventricular mural thrombus. Acute and chronic anticoagulation with heparin and warfarin, respectively, is given to prevent further thrombus formation and to reduce the incidence of systemic embolization.

Antithrombotic therapy in left ventricular thrombosis and systemic embolism

Left ventricular (LV) thrombi are responsible for significant morbidity and mortality in our society. Twenty-five percent of cardiogenic emboli are associated with acute and chronic myocardial infarction. With the development of noninvasive imaging techniques LV thrombi have been increasingly recognized as an important clinical entity; the imaging method of choice is two-dimensional echocardiography. LV mural thrombi occur in one third of Q wave anterior myocardial infarctions; their occurrence in patients with non-Q wave infarction and inferior Q wave myocardial infarction is less than 5%. More than half of all LV thrombi are formed within 48 hours of acute myocardial infarction, and nearly all thrombi have been formed within a week of infarction. The development of an LV thrombus is associated with some risk of systemic embolization. To prevent LV thrombosis and systemic embolism, full-dose heparin followed by warfarin therapy for at least 3 months is indicated for patients with large anterior infarctions and those with heart failure. The use of thrombolytic therapy does not reduce the risk of LV thrombus formation; few data exist on whether early coronary angioplasty reduces the risk of LV thrombus formation and the risk of embolization. The proper treatment for patients with chronic LV thrombi remains unknown.

The natural history of left ventricular thrombus in myocardial infarction: a rationale in support of masterly inactivity

One hundred five unselected and consecutive patients were prospectively studies after acute transmural myocardial infarction to assess the incidence of mural thrombus formation and to relate the presence of thrombus to patient outcome in terms of systemic embolic events, functional class and survival. In 87 patients, optimal quality two-dimensional echocardiographic studies were obtained and were repeated at daily intervals to detect mural thrombus formation. The site of infarction was anterior in 53 patients and inferior in 34. On admission, all patients received subcutaneous heparin and antiplatelet agents (aspirin, dipyridamole); none received full anticoagulant therapy. Left ventricular mural thrombus was visualized between 2 and 11 days (median 6) after the clinical onset of infarction in 21 (40%) of the 53 patients with anterior infarction. No patients with inferior infarction had echocardiographic evidence of thrombus formation. During follow-up of 22 to 51 months (mean 39), none of the 21 patients with mural thrombus had clinical evidence of systemic embolism. One patient with inferior and one with anterior infarction had a cerebral embolus 7 days and 9 months, respectively, after the acute event, but neither of these patients had echocardiographic evidence of left ventricular thrombus at any stage. Echocardiography performed at 1 and 2 years of follow-up showed persistent evidence of thrombus in only 8 (31%) and 5 (24%) of the 21 patients, respectively. On admission, the functional class of patients with anterior myocardial infarction and thrombus was similar to that of patients without ventricular thrombus.(ABSTRACT TRUNCATED AT 250 WORDS)

Two-dimensional echocardiography in the diagnosis of intracardiac masses: a prospective study with anatomic validation

The accuracy of two-dimensional echocardiography in the detection of intracardiac masses was verified in 334 patients who underwent cardiac catheterization in our laboratory over 21 consecutive months. A complete two-dimensional echocardiographic (2DE) examination was performed a day before catheterization. The presence or absence of a mass was verified at surgery in 77 patients who successively underwent mitral or aortic valve replacement (51), left ventricular aneurysmectomy with or without myocardial revascularization (25), and resection of atrial myxoma (2). In 32 patients 2DE revealed the presence of a mass-left or right atrial thrombi in 12, left atrial myxoma in 2, left ventricular thrombi in 16, and endocardial vegetations in 2. The other 45 patients were free of intracardiac masses on 2DE. Anatomic verification at surgery revealed the presence of an intracardiac mass in 34 patients. In 30 (true positives) of these, 2DE revealed the mass as well, and in 4 (false negatives) the presence of a mass had not been identified by 2DE. In 2 patients (false positives) the predicted mass was not found at surgery. Absence of a mass was correctly predicted by 2DE in 41 patients (true negatives). Thus 2DE detected intracardiac masses with sensitivity of 88.2% and a specificity of 95.3%. We recommend that 2DE be performed in all patients prior to hemodynamic study and/or cardiac surgery to enable safer management of patients with intracardiac masses during cardiac catheterization and/or cardiac surgery.

The usefulness of x-ray computed tomography for the diagnosis of myocardial infarction

Conventional and enhanced computed tomographic (CT) examinations were performed in 103 patients with myocardial infarction for evaluation of the diagnostic usefulness of CT. After intravenous bolus injection of contrast material, an initial filling defect and late enhancement of the infarcted myocardium appeared on the cardiac CT images. These two findings were direct evidence of myocardial infarction; the former was found mostly in the patient with recent myocardial infarctions, and the latter was recognized both in those with recent and those with "remote" infarctions. Wall thinning at the site of infarction was found by enhanced CT mostly in patients with anteroseptal or extensive anterior infarctions, and was rarely found in patients with inferoposterior infarctions. Left ventricular aneurysms and ventricular thrombi were found by enhanced CT in 39 and 23 of the 103 subjects, respectively, and the sensitivity of CT in detecting intracardiac thrombi was higher than that of two-dimensional echocardiography. Calcification of the myocardium and pericardial effusion associated with myocardial infarction were also detected by conventional nonenhanced CT. Thus, cardiac CT was found to be a useful test in evaluating patients with myocardial infarction.

Left ventricular mural thrombi secondary to acute myocardial infarction: predisposing factors and embolic phenomenon

Twenty-five patients with acute myocardial infarction were examined for ventricular thrombi using two-dimensional echocardiography. Six of 10 patients (60%) with an anterior wall infarction had an apical or apical-septal thrombus within the first week of hospitalization. None of the fifteen patients with an inferior wall myocardial infarction had a mural thrombus. Although the size of infarction in the patients with a thrombus was not significantly larger than in those who had an anterior wall infarction without a thrombus (43% +/- 10% vs. 31% +/- 7%, P less than 0.1), the severity and extent of dyskinesia or akinesia were more marked in the former group. Left ventricular function as determined by the nuclear blood pool scan ejection fraction was also significantly less for the former group than for the latter group (21% +/- 6% vs. 40% +/- 11%, P less than 0.02). Three of six patients with an intracavitary thrombus on echocardiography had systemic embolic during their hospital course. Postinfarction ventricular thrombi tend to occur in those patients with an anterior wall myocardial infarction who have far advanced wall motion abnormalities of the affected area, and overall poor left ventricular function. Although the number of patients was small, the high incidence of systemic embolization in the infarction subjects with echocardiographically proven thrombi indicates that these patients are at increased risk for such events.

Evaluation of intracardiac thrombus with computed tomography

Left atrial (LA) and left ventricular (LV) thrombus was evaluated by computed tomography in 56 patients. The patients were divided into 2 groups: Group I, 28 patients with mitral valve disease, and Group II, 28 patients with myocardial infarction. Computed tomography and 2-dimensional echocardiography were performed in all the patients studied. Cineangiocardiography was performed in all Group I and in 13 Group II patients. Open heart surgery or autopsy was performed in all Group I and 4 Group II patients. The sensitivity in detecting LA thrombus was 100% with computed tomography, 70% with angiocardiography, and 60% with 2-dimensional echocardiography. The specificity in detecting LA thrombus was 91% with computed tomography, 86% with 2-dimensional echocardiography, and 88% with angiocardiography. Thrombi located at the LA appendage were associated with great difficulties in detection by other methods, but were well delineated with computed tomography. LV thrombus was also visualized by computed tomography with similar or greater accuracy than other diagnostic methods, although the sensitivity and specificity were not ascertained because surgery or autopsy was performed in only a minority of Group II patients. Therefore, as far as the detection of intracardiac thrombus is concerned, computed tomography has the advantage of offering uniform slices of the heart in an attempt to detect thrombi in unknown areas of cardiac chambers, including the LA appendage or LV apex, without being disturbed by the surrounding cardiac and noncardiac structures. Thus, computed tomography has excellent accuracy in the detection of intracardiac thrombus.

Two dimensional echocardiography in the diagnosis of left ventricular thrombus. A prospective study of 67 patients with anatomic validation

Seventy-two patients, in whom a high prevalence of left ventricular thrombus (LVT) was anticipated, were studied prospectively by two-dimensional echocardiography (2DE). Adequate echocardiograms were obtained in 67 patients (93 percent). Presence or absence of LVT was verified at surgery in 51 patients undergoing aneurysmectomy, and at autopsy in 16 patients dying from acute myocardial infarction. Twenty-six patients had LVT and 41 did not. The LVT was defined echocardiographically as an echo-dense mass adjacent to asynergic left ventricular wall and distinct from the endocardial surface. Twenty-four of 26 LVT were correctly predicted by 2DE (sensitivity 92 percent). Absence of LVT was correctly predicted in 36 of 41 patients (specificity 88 percent). In five patients, LVT by 2DE was not anatomically confirmed (17 percent false positives). Thus, 2DE can detect or exclude the presence of LVT with a good sensitivity and specificity.

Two-dimensional echocardiographic diagnosis of left-atrial thrombus in rheumatic heart disease. A clinicopathologic study

Two-dimensional echocardiographic studies were performed in 293 patients with rheumatic heart disease who underwent open-heart mitral valve surgery during an 18-month period. Diagnostic confirmation of a left atrial thrombus was based on direct inspection of the left atrium during surgery and histopathologic examination. Two-dimensional echocardiographic recordings were reviewed. Of the 293 patients, 33 had left atrial thrombi by two-dimensional echocardiographic criteria. This diagnosis was confirmed at surgery and histopathologic study in 30 (specificity 98.8%). A thrombus was not found in three patients. In 21 other patients, left atrial thrombi were present but were not detected by two-dimensional echocardiography (sensitivity 58.8%). Ten of these 21 had thrombi in the left atrial cavity. In 11 patients, thrombi were located in the left atrial appendage, all of which were missed by two-dimensional echocardiography. Excluding these 11 left atrial appendage thrombi, the sensitivity of two-dimensional echocardiography for detecting left atrial cavity thrombi was 75.0%.

Diastolic mitral gradient without associated valvular stenosis: usefulness of two-dimensional echocardiography for a correct diagnosis

A diastolic gradient across the mitral valve is generally indicative of mitral valve stenosis. In the present study, echocardiography was used to demonstrate two less common causes of left ventricular inflow obstruction: one patient had a fibromuscular membrane beneath the valve, the other a large vegetation attached to the posterior leaflet of the mitral valve. Echocardiography proved to be the optimal imaging technique in each case.

Echocardiographic appearances of right atrial thrombus

A 17-year-old male presented with a four-day history of increasing shortness of breath and right basal pleuritic chest pain. Physical examination revealed central and peripheral cyanosis, sinus tachycardia, elevation of central venous pressure, hypotension, and added third heart sound. Echocardiography (M-mode and two-dimensional) showed a highly mobile mass in the right atrium apparently attached to the interatrial septum. A diagnosis of right atrial myxoma with pulmonary embolization was made and urgent surgery advised. At operation a string of thrombus in the right atrium (presumed from peripheral venous site) occluding a patent foramen ovale was found. The usefulness of echocardiography in diagnosing atrial thrombus and in differentiating clot from tumor is discussed.

Clinical correlations in patients with acute myocardial infarction and left ventricular thrombus detected by two-dimensional echocardiography

Eleven of forty-nine patients with acute myocardial infarction had left ventricular thrombus identified by two-dimensional echocardiography. The patients with thrombi had a greater incidence of transmural infarction, high-grade ventricular ectopy on ambulatory monitoring and lower radionuclide ejection fractions than the patients without thrombi. Most of the patients were receiving full-dose heparin and/or warfarin anticoagulation from the time of admission to the hospital. Thus the thrombi either developed prior to hospital admission or developed during anticoagulation therapy. Two patients with thrombi had peripheral emboli complicating their infarction. One of these patients was undergoing anticoagulation at the time of his embolus.

M mode and cross-sectional echocardiographic recognition of fibrosis and calcification of the mitral valve chordae and left ventricular papillary muscles

The echocardiographic appearance of fibrotic thickening and calcification of mitral valve chordae tendineae and left ventricular papillary muscles in 17 patients is described. Pathologic proof of excessive fibrosis or calcification was obtained in five patients. In a sixth patient, calcium was demonstrated on angiography to extend from the chordae into papillary muscle. The characteristic feature of chordal and papillary muscle fibrosis and calcification is the presence of highly echogenic densities best visualized within the left ventricle at a level below the mitral valve leaflets. The more inferior location of these densities, within the body of the left ventricle, enables them to be easily differentiated from densities indicating fibrosis and calcification of the mitral valve anulus. The pattern of chordal and papillary muscle fibrosis and calcification was frequently associated with mitral anular calcification, aortic valve fibrosis or calcification and left atrial enlargement. One patient had rheumatic mitral valve disease. Many patients had mitral regurgitation and most had a history, physical examination and radiologic findings compatible with congestive heart failure. Although the origin and importance of the chordal and papillary muscle changes reported are not known, their frequent association with mitral regurgitation and with congestive heart failure suggests possible interrelations.

Limitations of echocardiographic techniques in evaluation of left atrial masses

Four patients with large left atrial masses documented angiographically or pathologically, or both, were studied with M mode echocardiography (four patients) and two dimensional echocardiography (three patients) within 2 to 5 days of angiographic or pathologic diagnosis. The left atrium appeared clear of echos in two patients subsequently documented to have a left atrial thrombus weighing 35 and 100 g, respectively, and located within the body of the left atrium. Definitely abnormal echoes were visualized in a third patient only in the inferior aspect of the left atrium immediately beneath the posterior root of the aorta. Subsequently, a 70 g left atrial myxoma filling almost the entire left atrium was found. In the fourth patient, who had a 125 g left atrial myxoma, the two dimensional four chamber apical view demonstrated tumor filling almost the entire left atrium. Long axis cross-sectional and M mode echocardiograms less clearly demonstrated the extent of the mass. Even large left atrial tumors located within the body of the left atrium may not be apparent or may be underestimated in size by currently available ultrasonic techniques. The relatively homogenous nature of certain masses may be, in part, responsible for the inability to visualize some of them adequately with echocardiography.