Incidence of left-ventricular thrombosis after acute transmural myocardial infarction. Serial evaluation by two-dimensional echocardiography

Fate of left ventricular thrombi in patients with remote myocardial infarction or idiopathic cardiomyopathy

Although left ventricular thrombi that form acutely after myocardial infarction frequently resolve spontaneously or with anticoagulant therapy, the fate of left ventricular thrombi in patients with remote myocardial infarction or with idiopathic cardiomyopathy remains unknown. To determine the natural history of such chronic left ventricular thrombi, we performed serial echocardiograms on 51 patients with remote myocardial infarction (greater than or equal to 3 months; mean, 31 +/- 41 months) and on nine patients with idiopathic dilated cardiomyopathy. Mean follow-up was 24 +/- 22 months during which 3.5 +/- 1.4 echocardiograms were obtained. Studies were interpreted by blinded observers, and an increase or decrease of more than 5 mm in maximal thrombus thickness was defined as significant. Among all 60 patients left ventricular thrombi were unchanged in 24 (40%), completely resolved in 24 (40%), decreased in size in four (7%), increased in size in five (8%), and decreased and then increased in size in three (5%). Results in patients with remote infarction and idiopathic cardiomyopathy were similar. Warfarin therapy, which was at the discretion of the primary physician, was associated with a higher prevalence of thrombus resolution compared with no therapy (59% vs. 29%, p = 0.02). Definite systemic emboli occurred in seven patients (12%), all at times while they were not anticoagulated. Among the 48 thrombi that were present on two or more echocardiograms, changes in thrombus shape (classified as protruding or flat) occurred in only 16%, and changes in thrombus movement (classified as mobile or immobile) occurred in only 10%.(ABSTRACT TRUNCATED AT 250 WORDS)

Increasing precordial QRS voltage correlates with improvement in left ventricular function following anterior myocardial infarction

To evaluate whether changes in QRS voltage reflect changes in left ventricular function after myocardial infarction, 28 patients were studied following anterior myocardial infarction. Two-dimensional echocardiograms and 12-lead electrocardiograms were obtained during the acute phase of the infarction and again after at least 30 days of recovery (mean, 8 +/- 8 months). At follow-up, 11 patients (group A) showed improvement in left ventricular systolic function; 9 had increased net QRS voltage in V1-6 and 8 in V1-4. No improvement in ventricular function was found in 17 patients (group B); 7 had increased QRS voltage in V1-6 (p less than 0.05 vs group A) and only 5 in V1-4 (p less than 0.05 vs group A). For detection of improved left ventricular function, the sensitivity, specificity, and predictive value of the change in net QRS voltage for leads V1-6 was 82%, 59%, and 56% respectively, and for leads V1-4 was 73%, 71%, and 62% respectively. Neither R wave voltage, Q wave voltage, nor the total number of Q waves was reliable for identifying patients with improving left ventricular function. Thus, increasing net QRS voltage in the precordial electrocardiographic leads during long-term follow-up after anterior myocardial infarction correlates with and has a reasonable sensitivity for detection of improvement in left ventricular systolic performance.

Severe disseminated intravascular coagulation associated with massive ventricular mural thrombus following acute myocardial infarction

We describe three patients who developed severe disseminated intravascular coagulation associated with large ventricular mural thrombi shortly after presenting with acute myocardial infarction. To our knowledge this association has not been reported before.

Surgical removal of a mobile, pedunculated left ventricular thrombus: report of 4 cases

During an 11-month period, 4 patients underwent surgical removal of a mobile, pedunculated left ventricular thrombus. All 4 patients had a history of myocardial infarction. Two of the 4 patients had systemic emboli, and in the 2 others, the ventricular thrombi were removed to prevent emboli. The thrombus was removed during the acute phase of myocardial infarction in 2 patients and one and two years, respectively, following the infarct in the remaining 2 patients. Concomitant coronary artery bypass grafting was performed in 3 patients. There were no early or late deaths, and none of the patients had clinical or echocardiographic evidence of recurrent thrombi or emboli at follow-up 3 to 15 months later. These results indicate that left ventricular thrombectomy might be an effective treatment for patients with mobile, pedunculated, left ventricular thrombi. However, additional experience is required to compare surgical and medical treatment.

Risk factors for embolisation in patients with left ventricular thrombi and acute myocardial infarction

Risk factors for systemic embolisation in patients with ventricular thrombi caused by an acute myocardial infarction were studied in 150 consecutive patients with an infarction of the anterior wall. Serial echocardiograms were performed 2-10 days after the acute event and patients were followed up for three months. Anticoagulation treatment was started only after the detection of thrombi. Of the 55 patients in whom a thrombus developed, 15 (27%) had peripheral emboli between 6-62 days; but only two (2%) of 95 patients without thrombus had emboli. Among 15 variables, the best single predictors of embolisation were age greater than 68 years (80% sensitive, 85% specific), pendulous thrombus (60%, 93%), and independent thrombus mobility (60%, 85%). Logistic regression analysis showed that a formula that included patient age, thrombus area, and the length of thrombus in the ventricular lumen predicted embolisation (sensitivity 87%, specificity 88%). There was no correlation between age and the thrombus variables. The risk of embolisation from left ventricular thrombi in acute anterior myocardial infarction can be accurately assessed from patient age and echocardiographic features. The risk of peripheral emboli is high in patients with left ventricular thrombi and those aged greater than 68.

Reduced incidence of left ventricular thrombi with intravenous streptokinase in acute anterior myocardial infarction: prospective evaluation by cross-sectional echocardiography

Forty-five consecutive patients with transmural anterior acute myocardial infarction were prospectively studied to determine the effect of intravenous streptokinase on the incidence of left ventricular thrombi. Three patients died. The remaining patients were divided into 2 groups. Group 1 patients (n = 22) received 750,000 units of intravenous streptokinase within 6 hours of onset of symptoms. Neither thrombolytic therapy or anticoagulants were administered to 18 patients in group 2. Cross-sectional echocardiography was performed 8 to 10 days following acute myocardial infarction to detect left ventricular thrombus. Technically satisfactory echocardiography was not possible in 2 patients. Apical akinesia or dyskinesia was observed in all patients. No patient in the treated group developed left ventricular thrombus compared with 8 of 18 (44.4%) in group 2 (P less than 0.05). One patient in the control group sustained an embolic cerebrovascular accident. Thus intravenous streptokinase significantly reduces the incidence of left ventricular thrombus formation in patients of transmural anterior acute myocardial infarction.

Left ventricular thrombus formation after first anterior wall acute myocardial infarction

The characteristics of the left ventricle and coronary arteries associated with left ventricular (LV) thrombus in patients with recent anterior acute myocardial infarction were defined. Of 77 patients studied, 35 (46%) had LV thrombi. The presence of LV thrombus was not correlated to the extent of coronary artery disease. The frequency of LV thrombus progressively increased with groups of increasing wall motion abnormality as determined by the extent of akinesia and dyskinesia (%AD) (%AD 0 to 14, thrombus present in 3 of 16 [19%], %AD 15 to 29, thrombus in 8 of 27 [30%]; %AD greater than or equal to 30%, thrombus in 24 of 34 [71%]; p less than 0.001) and with increasingly severe degrees of early ventricular shape change (normal or mildly abnormal contour, 16% with thrombus; moderately abnormal contour, 36% with thrombus; severely abnormal contour, 70% with thrombus; p less than 0.001). Patients with thrombi had higher diastolic (249 +/- 55 vs 225 +/- 48 ml; p less than 0.05) and systolic (158 +/- 48 vs 120 +/- 45 ml; p less than 0.001) volumes than patients without thrombi, respectively. A stepwise discriminant analysis identified ejection fraction, extent of early shape change and LV end-diastolic pressure as independent correlates of LV thrombus after acute myocardial infarction.

Serial changes in left ventricular wall motion by two-dimensional echocardiography following anterior myocardial infarction

To evaluate the time course of spontaneous changes in wall motion following anterior infarction, we prospectively performed serial apical four-chamber two-dimensional echocardiography on 45 consecutive long-term survivors of initial transmural anterior infarction. Studies were performed on admission (1 +/- 1 days), 1 week after admission (6 +/- 2 days), at discharge (15 +/- 8 days), and at long-term follow-up (235 +/- 186 days). Ventricular size was expressed as end-diastolic area in square centimeters. Wall motion for this tomographic section was evaluated as the percent change in left ventricular area from end diastole to end systole (% LVA). Patients were grouped on the basis of significant differences for %LVA between the first and fourth studies. Group I (n = 14) had improved wall motion (23 +/- 5% to 38 +/- 9%); group II (n = 23) did not change (22 +/- 9% to 23 +/- 11%); and group III (n = 8) had worsened wall motion (28 +/- 6% to 18 +/- 7%). End-diastolic area did not change over the study period for groups I and II but increased significantly for group III (30 +/- 6 to 35 +/- 4 cm2, p less than 0.05). Most of the increase in end-diastolic area for group III was between the third and fourth study. The percent improvement (%IMP) in wall motion for patients in group I who did not have ventricular fibrillation outside the hospital expressed in days (t) following infarction fit an exponential curve (%IMP = 100-100e-(.108t) that predicts that 70% of eventual recovery will occur in the first 15 days post-infarction. We conclude that changes in left ventricular size and wall motion occur following anterior infarction with improvement or worsening occurring spontaneously in some patients. If improvement occurs, it should be evident within 2 weeks of infarction; infarct expansion in this select group of long-term survivors occurred primarily after discharge.

Abnormal blood pathways in left ventricular cavity in acute myocardial infarction. Experimental observations with special reference to regional wall motion abnormality and hemostasis

To elucidate the mechanism of regional hemostasis in the left ventricular (LV) cavity during myocardial infarction, the blood pathway in LV cavity was examined with contrast echocardiography injected from the left atrium before and after coronary ligation in nine canines. Before coronary ligation, contrast echoes spread over LV cavity with one rush. After ligation, smokelike echoes indicating hemostasis were observed at the apical middle of the LV cavity in five dogs with apical akinesis and at the apical area in four dogs with apical dyskinesis. The contrast echoes did not reach the apex within one diastolic period but turned upward to the outflow tract in the middle of the cavity in all dogs. In the cardiac beats that followed, some contrast echoes spread slowly toward the apex, forming a thin layer along the posterior wall in cases with akinesis but not in cases with dyskinesis. The area separated from the blood pathway developed where the smokelike echoes had been developed. Tachycardia exaggerated the abnormality of blood pathway and widened the contrast echo-free area. The abnormal pathway of the blood in apical myocardial infarction develops hemostasis in the apex. This should be one of the mechanisms of thrombus formation in myocardial infarction.

Recurrent left ventricular mural thrombi in a patient with acute myocarditis

A case of acute myocarditis with recurrent left ventricular mural thrombi in a 59-year-old man is reported. Two-dimensional echocardiogram demonstrated left ventricular mural thrombus with apical dyskinesis on the 2nd day after the onset of chest oppression. No hemoagglutination abnormalities were present. Anticoagulation treatment with heparin was initiated. A two-dimensional echocardiogram obtained on the 15th day showed that the left ventricular wall motion had become normal and that the thrombus had disappeared. However, on the 38th day, a new pedunculated free mobile thrombus was found in the apical part of the left ventricle despite the normal wall motion. By the 46th day, the new thrombus had disappeared. The present case suggests that mural thrombi can occur in the absence of left ventricular dyskinesis and dilatation. Anticoagulation therapy resolved the mural thrombi but could not prevent the recurrence at the apex. Thus, in acute myocarditis, a mural thrombus may appear as a result of the endocardial damage, even when blood stasis is absent.

Left atrial spontaneous echo contrast in mitral valve disease: an indicator for an increased thromboembolic risk

The incidence of left atrial spontaneous echo contrast was evaluated in 52 patients with isolated or predominant mitral valve stenosis (Group 1) and 70 other patients who had undergone mitral valve replacement (Group 2). All patients were studied by conventional transthoracic and transesophageal two-dimensional echocardiography. Spontaneous echo contrast could be visualized within the left atrium in 35 Group 1 patients (67.3%) (including 7 patients with sinus rhythm) and 26 Group 2 patients (37.1%) (all with atrial fibrillation). Patients with spontaneous echo contrast had a significantly larger left atrial diameter and a greater incidence of both left atrial thrombi and a history of arterial embolic episodes than did patients without spontaneous echo contrast. Association between spontaneous echo contrast and left atrial thrombi and a history of arterial embolization (considered individually or in combination) showed a high sensitivity and negative predictive value. It is concluded that spontaneous echo contrast is a helpful finding for identification of an increased thromboembolic risk in patients with mitral stenosis and after mitral valve replacement.

Left ventricular thrombosis in acute transmural myocardial infarction

To determine the incidence and natural history of left ventricular thrombosis in acute transmural myocardial infarction we performed serial two-dimensional echocardiography in 51 patients. Seventeen patients had inferior infarcts. None of these developed left ventricular thrombosis. The remaining 34 patients had anterior infarcts. Ten of these developed left ventricular thrombus at an average of 4 +/- 2 days after admission. All patients with left ventricular thrombosis had apical akinesia or dyskinesia. Patients with anterior myocardial infarction and akinesia or dyskinesia of the apex are at high risk of developing left ventricular thrombosis. Peak aspartate aminotransferase and lactate dehydrogenase enzyme activity were of little value in identifying this high risk group.

Transient left atrial mobile thrombus in acute myocardial infarction--a case report

The authors report a fifty-year-old woman with acute inferior myocardial infarction in whom left atrial mobile thrombus was found by echocardiography. They believe this to be the first echocardiographic documentation of such a thrombus after acute myocardial infarction. The combination of the stagnant flow in the left atrium due to atrial ischemia, the low output state due to left ventricular dysfunction, and the hemoconcentric tendency from use of diuretics might have played a role in the present thrombus formation. The thrombus was safely lysed without complication after intravenous urokinase.

Left ventricular full-thickness cardiomyoplasty with pericardial neoendocardium: experimental development of a surgical procedure

Cardiomyoplasty, a surgical procedure using stimulated skeletal muscle graft to replace or repair damaged myocardium, has been successfully performed in experimental animals and clinical patients. Whenever feasible, endocardium of the damaged myocardial segment is retained and partial-thickness cardiomyoplasty should be carried out. However, if this procedure were to be applied to enlarge a hypoplastic ventricle or to maintain normal dimensions of the ventricular cavity in some repairs in adults, full-thickness replacement of the ventricular wall with contractile skeletal muscle mass would be required. To develop such a technique, several canine experiments were carried out. In 7 dogs, "simple full-thickness cardiomyoplasty" was performed by using a latissimus dorsi muscle graft to repair a full-thickness left ventricular wall defect. We found it was difficult to obtain adequate hemostasis between the nonscarred myocardial tissue and the skeletal muscle graft, and excessive suturing to obtain hemostasis resulted in strangulation of the muscle grafts. The skeletal muscle-blood interface in the left ventricle was found to be highly thrombogenic. The perioperative hemorrhage and the risk of muscle graft strangulation by excessive sutures were avoided by using a pericardial patch as neoendocardium in 5 dogs that underwent similar full-thickness cardiomyoplasty procedures. Although the pericardial neoendocardium was not fully antithrombogenic in this canine model, endothelialization of the endocardium occurred within several weeks after operation. Thus, when combined with an implantable synchronized burst stimulator, this technique may in the future provide an effective "full-thickness dynamic cardiomyoplasty" to enlarge the ventricles and augment myocardial function in select patients.

Echocardiography and coronary artery disease: current and future applications

Echocardiographic techniques are becoming more widespread for evaluating patients with known or suspected coronary artery disease. Because it affords an excellent overall view of the heart, two-dimensional echocardiography, rather than M-mode echocardiography, is the imaging procedure of choice when dealing with coronary artery disease. This technique can be used to make the initial diagnosis of acute myocardial infarction, diagnose complications, and assess prognosis following myocardial infarction. Additionally by combining this test with stress testing, latent coronary artery disease can be detected. Recovery of wall motion can be assessed following interventions such as thrombolysis or balloon angioplasty. Investigational and future uses include tissue characterization, which may allow detection of ischemic but potentially viable myocardium, direct coronary visualization for detection of atherosclerotic involvement of the proximal coronary arteries and myocardial contrast echocardiography. The latter technique allows visualization of perfusion by way of injecting contrast material into the coronary circulation. This has been demonstrated to be an accurate means of determining myocardial infarction size in an animal model and is currently being used in a number of centers in patients at the time of cardiac catheterization. In summary two-dimensional echocardiography currently allows assessment of patients with myocardial infarction from the time of their presentation through their convalescent period with respect to diagnosis, prognosis and presence of complications. Exercise echocardiography can diagnose latent coronary artery disease. The newer investigational techniques show promise for furthering our ability to evaluate patients with coronary artery disease using echocardiography.

Atrial septal aneurysm: association with cerebrovascular and peripheral embolic events

Patient records in 36 consecutively identified patients with typical echocardiographic findings of atrial septal aneurysm were reviewed. Ten of the 36 (28%) had cerebrovascular events. Of these 10, 5 had completed strokes of definite embolic origin on the basis of clinical, angiographic, and computed tomographic findings; 2 had transient ischemic attacks of probable embolic origin. One of the 36 patients had a definite peripheral vascular embolus. Thus, 6 of 36 consecutively identified patients with atrial septal aneurysm (17%) had definite embolic events and 8 of 36 (22%) had definite or possible embolic events. The cause of the association between atrial septal aneurysm and emboli is unknown. While aneurysm-associated thrombus has been suggested, the high proportion (90%) of patients with interatrial shunting demonstrated by contrast echocardiography in this study suggests paradoxical embolization as a potential cause. Whatever its mechanism, the high prevalence of embolic events in this series strongly supports the premise that atrial septal aneurysm is a cardiac abnormality with embolic potential.

Myocardial infarct expansion, infarct extension, and reinfarction: pathophysiologic concepts

Infarct expansion and infarct extension are events early in the course of myocardial infarction with serious short- and long-term consequences. Infarct expansion, disproportionate thinning, and dilatation of the infarct segment probably begin within hours of acute infarction and usually reach peak extent within seven to 14 days. Clinical data suggest that infarct expansion occurs in approximately 35% to 45% of anterior transmural myocardial infarctions and to a lesser extent in infarctions at other sites. Although expansion usually develops in large infarcts, the extent of transmural necrosis rather than absolute infarct size predicts its occurrence. Expansion has an adverse effect on infarct structure and function for several reasons. Functional infarct size is increased because of infarct segment lengthening, and expansion results in over-all ventricular dilatation. Thus, patients with expansion of an infarct have poorer exercise tolerance, more congestive heart failure symptoms, and greater early and late mortality than those without expansion. Infarct rupture and late aneurysm formation are two additional structural consequences of infarct expansion. Experimental and clinical data suggest that the incidence and severity of expansion can be modified by interventions. Increased ventricular loading conditions and steroidal and nonsteroidal antiinflammatory agents make expansion more severe. Reperfusion of the infarct segment and pharmacologic interventions that decrease ventricular afterload lessen the severity of expansion. Previous myocardial infarction and preexisting ventricular hypertrophy may also limit the development of infarct expansion. Infarct extension is defined clinically as early in-hospital reinfarction after a myocardial infarction. The pathologic finding of infarct extension is necrotic and healing myocardium of several different recent ages within the same vascular territory. Although this pathologic criterion usually cannot be verified, studies employing invasive and noninvasive assessment of patients with early reinfarction provide evidence that the new myocardial injury is usually in the same vascular risk region as the original infarction. A variety of different criteria have been applied in the clinical diagnosis of infarct extension, and this has resulted in a large range of estimated frequencies from under 10% to as high as 86%. High estimates are found in studies using one or two nonspecific criteria such as ST segment shift or reelevation of total CK. The lowest rates have been found when combinations of criteria are used.(ABSTRACT TRUNCATED AT 400 WORDS)

Postinfarction angina

In conclusion, the PIA patient is at high risk, with higher early as well as late mortality. The pathophysiology of PIA is complex and may vary from patient to patient. The concepts of ischemia at a distance and ischemia in the infarct zone have led to a better understanding of early PIA. Coronary spasm may play an important role in most PIA patients as in the general population of patients with angina pectoris. Medical therapy is efficacious in many, although it may on rare occasion aggravate myocardial ischemia. Urgent coronary arteriography is generally safe and should be performed as soon as possible for medically refractory PIA. CABG appears to be safe in experienced hands, but its timing must be individualized. The IABP should be reserved for more unstable patients for fear of vascular complications. Randomized controlled trials such as the BARI Trial will further compare PTCA with CABG.

Cerebrovascular accidents in acute myocardial infarction

Cerebral ischemia was recorded in 1.9% of 1277 patients with myocardial infarction. In most cases ischemia involved the carotid artery system, usually causing a hemiparesis or hemiplegia. Patients were mostly elderly, and the ischemic episode worsened their prognosis. The pathogenesis was surely often of embolic origin but several facts suggest that other mechanisms were also involved. Anticoagulant therapy, at least in the form in which it was used in these patients, i.e. subcutaneous administration of calcium heparin 5000 I.U. b.i.d. for thrombophlebitis prophylaxis, does not seem to prevent these complications.

Increased embolic risk in patients with left ventricular thrombi

Although left ventricular thrombi are associated with an increased embolic risk in the first few weeks after acute myocardial infarction, the long-term risk remains undefined. To ascertain the incidence of strictly defined systemic emboli, we followed 85 patients with echocardiographically documented left ventricular thrombi. At the time of the entry echocardiogram, most patients (n = 57) had remote myocardial infarction, while 19 had recent (less than 1 month) infarction, and nine had idiopathic cardiomyopathy. Because of the difficulty in classifying events as embolic in patients with advanced atherosclerosis, a matched control group of 91 patients without thrombi was also studied. The thrombus and control groups were similar with regard to recent myocardial infarction, remote infarction, anterior infarction, ejection fraction, atrial fibrillation, echocardiographic referral for source of emboli, and warfarin therapy. During a mean follow-up of 22 months after echocardiography, embolic events occurred in 13% (11 of 85) of patients with thrombi compared with 2% (two of 91) control patients (p less than .01). The actuarial probability of being embolus free at 2 years after echocardiography was 86% in patients with thrombi compared with 97% in control patients (p less than .01). All embolic events occurred greater than 1 month after myocardial infarction (range 1 to 96 months). The only clinical or echocardiographic features predictive of embolization were protrusion and mobility of thrombus (both p less than .02). We conclude that the incidence of embolic events is definitely increased in patients with left ventricular thrombi compared with control subjects during long-term follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Indium-111 platelet scintigraphy and two-dimensional echocardiography for detection of left ventricular thrombus: influence of clot size and age

Two-dimensional echocardiography and indium-111 platelet scintigraphy were performed on 50 dogs to determine the influence of clot age and size on the detection of experimentally induced left ventricular mural thrombus. Thrombus was induced by apical infarction and injection of a sclerosing agent and thrombin. The animals were classified into four groups according to the time of indium-111 platelet injection after thrombus induction: Group I (17 dogs, 1/2 hour after induction; 3 dogs, before induction), Group II (12 dogs, 24 hours after induction) and Group III (12 dogs, 1 week after induction). In Group IV (six control dogs) apical infarction was produced, but thrombin was not injected; indium-111 platelets were injected 1/2 to 1 hour after infarction. The dogs were studied by indium-111 platelet scintigraphy and by two-dimensional echocardiography 1/2 to 5 hours (Group I) and 1 to 5 and up to 72 hours (Groups II to IV) after platelet administration and before death was induced. Two-dimensional echocardiography showed the best overall sensitivity for detection of acute thrombus (97%; 29 of 30). The sensitivity of indium-111 platelet scintigraphy was 86% (18 of 21) for clots greater than or equal to 0.08 ml in size, and 67% (20 of 30) for detection of all clots. Thrombus did not form in 14 dogs of Groups I to III and in 6 of 6 control dogs. The specificity of scintigraphy was 100% (20 of 20) compared with 80% (16 of 20) for echocardiography. Echocardiography was more sensitive than scintigraphy for detecting very small clots in this experimental model.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous morphologic changes in left ventricular thrombi: a prospective two-dimensional echocardiographic study

Previous retrospective echocardiographic studies have reported a higher embolic potential of left ventricular thrombi with protruding configuration and patterns of mobility. The present study was performed to prospectively assess the shape and mobility patterns of left ventricular thrombi and their spontaneous changes with time. Two-dimensional echocardiograms were obtained in 109 consecutive patients with acute anterior myocardial infarction within 24 hr of the onset of symptoms, every 24 hr until day 5, every 48 hr until day 15, and then every month for a follow-up of 1 to 29 (mean 14 +/- 8) months in the survivors. None of the patients were treated with anticoagulants or platelet inhibitors during the study period. Left ventricular thrombi, detected in 59 patients (54%), appeared from 1 to 362 (mean 12 +/- 47) days after myocardial infarction. At first detection, the shape was mural in 21 patients and protruding in 38; patterns of mobility were present in eight patients. During follow-up, changes in the shape of the thrombi were noted in 24 patients (41%; from mural to protruding in nine, from protruding to mural in 15). These variations were encountered between 2 and 490 (mean 64 +/- 117) days after the first observation of the thrombus. Patterns of mobility, previously detected in eight patients, disappeared in five of eight within 2 to 28 (mean 14 +/- 11) days.(ABSTRACT TRUNCATED AT 250 WORDS)

Prophylactic anticoagulation for left ventricular thrombi after acute myocardial infarction: a prospective randomized trial

Thirty patients with a first episode of an anterior acute myocardial infarction (AMI) without a history of cardiac disease were prospectively randomized into a prophylactic heparin-treated group (group I) and a control nonanticoagulated group (group II) within 12 hours of the onset of chest pain to determine the effectiveness of anticoagulation for preventing left ventricular (LV) thrombi. Serial two-dimensional echocardiograms were performed during the hospital stay and patients were followed clinically for systemic emboli for 1 month after discharge from the hospital. Thirty-one percent of patients in group I (4/13) and 35% of patients in group II (6/17) developed LV thrombi on two-dimensional echocardiograms. There was no statistical difference in the incidence of LV thrombi between the two groups (p greater than 0.05). Infarct size as determined by creatine phosphokinase isoenzymes (2,386 +/- 1,568 vs 2,083 +/- 1,462 IU for groups I and II, respectively; p greater than 0.05), wall motion score (12.7 +/- 5 vs 10.7 +/- 5 for groups I and II, respectively; p greater than 0.05) and wall motion index (1.8 +/- 0.6 vs 1.8 +/- 0.56 for groups I and II, respectively; p greater than 0.05) were not statistically different between the two groups of patients. One patient in both groups had an embolic event. In conclusion, prophylactic anticoagulation in high-risk AMI patients for LV thrombus development does not prevent LV thrombus formation during the acute and subacute stages of an AMI. The results also suggest that anticoagulation may not prevent systemic embolization.

Increased occurrence of left ventricular thrombi during early treatment with timolol in patients with acute myocardial infarction

To examine whether early intervention with timolol influences the occurrence of left ventricular thrombi in acute anterior myocardial infarction, 40 patients with acute anterior myocardial infarction admitted to hospital within 6 hr of onset of symptoms were randomly assigned to receive intravenous followed by oral timolol maleate or placebo. Five (25%) of 20 patients in the placebo group and 14 (73.7%) of 19 patients with confirmed infarction in the timolol group developed a left ventricular apical thrombus as detected by two-dimensional echocardiography from 2 to 10 days after inclusion (p less than .005). Patients received anticoagulants only after a left ventricular thrombus had been diagnosed. Only one patient with thrombus suffered peripheral embolization (timolol group). The treatment groups were comparable with respect to location of regional left ventricular dysfunction, electrocardiographic changes, and infarct size estimated by creatine kinase release. However, computer-assisted regional wall motion analysis demonstrated significantly reduced apical wall motion in the timolol group compared with the placebo group (p less than .01). Also, the mean heart rate during the first 10 days after the acute infarction was reduced by 13% in the timolol group (p less than .001). The reduction in heart rate and left ventricular apical wall motion caused by timolol in patients with acute anterior myocardial infarction may increase the occurrence of left ventricular thrombi.

Identification of intracardiac thrombi in stroke patients with indium-111 platelet scintigraphy

Platelet scintigraphy (PSC) with indium-111 labelled platelets has been confirmed as an adequate method for the detection of intracardiac thrombi in patients with heart disease. We performed PSC of the heart and the neck vessels in 27 stroke patients with suspected cardiac embolism and as control on 10 patients with atherosclerotic lesions of the carotid arteries without evidence of heart disease. The carotid PSC was positive in 6 of 10 patients with carotid disease, and twice in the 27 with suspected cardiac embolism. In these 27 the PSC of the heart indicated pathological conditions 13 times. Pathological platelet accumulations could be visualized in 3 cases in the atrial space, in 9 cases in the region of the left ventricle, and once at the aortic valve. Scintigraphy was negative in all 10 patients with atherosclerosis of the neck vessels. The two-dimensional echocardiography revealed pathological findings in 8 of the 13 patients with positive heart PSC (3 with intraventricular thrombi, 3 with valvular disease, 2 with decreased ventricular contractility) and was normal in the 10 control patients. Open-heart surgery was performed in 2 patients with pathological PSC and revealed an intracardiac thrombus. Three of 4 patients with positive atrial PSC showed mitral or aortic valve disease. These results suggest that PSC can provide a valuable method for detecting cardiac thrombi in stroke patients.

Thrombosis and embolism from cardiac chambers and infected valves

In a number of cardiac conditions (acute myocardial infarction, chronic left ventricular aneurysm, dilated cardiomyopathy, infective endocarditis and atrial fibrillation in the absence of valvular disease), the risk of embolism gives cause for concern. Although anticoagulation with warfarin (Coumadin)-derivatives has been shown to be effective in some of these situations, there is no evidence regarding the role of antiplatelet agents. The common factor in the thromboembolic potential of acute myocardial infarction, chronic left ventricular aneurysm and dilated cardiomyopathy is mural thrombus. This can be detected by two-dimensional echocardiography and indium-111 platelet scintigraphy. Although of value in elucidating the natural history of mural thrombus, in most cases, management is not substantially aided by these investigations. In patients with extensive myocardial infarction, particularly anterior infarction, moderate intensity anticoagulation started soon after hospital admission reduces the rate of embolism. After 8 to 12 weeks, embolic risk is low so that anticoagulants can usually be discontinued. Patients with chronic left ventricular aneurysm have a low incidence of embolism; anticoagulation is, therefore, inappropriate. Dilated cardiomyopathy is associated with a high risk of embolism; moderate intensity anticoagulation may be advisable in many such cases. Little information is available regarding the incidence of thromboembolism or the role of antithrombotic therapy in the patient with a diffusely dilated left ventricle due to ischemic heart disease. In native valve infective endocarditis, the risk of hemorrhage is high, and the efficacy of conventional anticoagulants unclear; thus, anticoagulation should not be instituted for the cardiac condition as such. However, in prosthetic valve endocarditis, the risk of embolism seems to be very high, and anticoagulant therapy should be continued, but with great care because there is a substantial risk of cerebral hemorrhage. Atrial fibrillation in patients with valvular heart disease is dealt with in a previous review. Patients with nonvalvular atrial fibrillation are at varying risk of embolism, depending on the etiology of the arrhythmia; trials of antithrombotic therapy are needed for the various subsets of patients. In most elderly patients, the etiology is not known, and their stroke risk is high. The risk of embolism in younger patients with idiopathic atrial fibrillation is so low as to make any antithrombotic therapy unnecessary.(ABSTRACT TRUNCATED AT 400 WORDS)

Detection of ventricular thrombosis in acute myocardial infarction: value of indium-111 platelet scintigraphy in relation to two-dimensional echocardiography and clinical course

In order to detect left ventricular (LV) thrombosis, 111In-platelet scintigraphy and two-dimensional echocardiography were performed in 40 patients 15 days +/- 6 days after acute myocardial infarction. A dual isotope subtraction method, using 111In-platelet scintigraphy and 99mTc-blood pool scintigraphy, was used to assess LV platelet deposition expressed as LV counts per pixel. Seven patients (group A) had a positive 111In-platelet scintigram and 33 patients (group B) had a negative 111In-platelet scintigram (LV counts per pixel: 0.56 +/- 0.23 and 0.28 +/- 0.19, respectively, P less than 0.05). Three group A patients but no group B patients had a positive echocardiogram. Arterial embolism was noted in four patients, of whom two showed both positive echocardiogram and platelet scintigram. LV counts per pixel were 0.57 +/- 0.13 and 0.31 +/- 0.21, respectively (P less than 0.02) in patients with and without arterial embolism. Thus, both 111In-platelet scintigraphy and two-dimensional echocardiography can detect LV thrombosis. 111In-platelet scintigraphy may help to define patients at risk for embolization and may be used in conjunction with echocardiography to study the effect of antithrombotic therapy.

Morphological changes in endocardium subjected to global ischaemia

To provide insight into the effects of severe ischaemia on endocardium, the sequence of morphological changes which develop in the endocardium of the isolated rat heart subjected to 0-12 hours of global ischaemia at 37 degrees C was examined. A progression of changes occurred. Following one or more hours of ischaemia crater-like depressions and blebs appeared on the luminal surfaces of ventricular endothelial cells, with margination and clumping of nuclear chromatin, loss of glycogen granules, swelling of mitochondria, and the development of subendothelial membrane-bound dilatations of myocytes. Following two or more hours of ischaemia there was progressive separation of endothelial cells along their intercellular boundaries and desquamation of an increasing proportion of these cells. In regions of desquamation the surface was initially smooth due to persistence of the lamina densa of the basal lamina, but after longer periods of ischaemia the surface became rough with exposure first of the subendothelial connective tissue fibres (4 hours) and eventually of cardiac muscle cells (12 hours).

Prognostic implications of regional hyperkinesia and remote asynergy of noninfarcted myocardium

To determine the clinical significance of regional hyperkinesia and remote asynergy of noninfarcted areas in patients with a first acute myocardial infarction (AMI), 2-dimensional echocardiography was performed in 113 consecutive patients within 12 hours after admission to the coronary care unit. In 98 patients (87%) all segments of the left ventricular wall were recorded. Infarct-associated asynergy was anterior in 63 and inferior in 35 patients. Regional hyperkinesia was present in 66 patients (67%)--44 of 63 with anterior (69%) and 22 of 35 with inferior (63%) infarcts--and was more frequently seen in patients with 1- and 2-vessel coronary artery disease (CAD) than in patients with 3-vessel CAD (87 and 72% vs 25%, p less than 0.001). In contrast to enzymatic infarct size, absence of regional hyperkinesia was significantly associated with a higher left ventricular wall motion score (p less than 0.01). Twenty patients died within 30 days after onset of AMI; in 15 (75%) regional hyperkinesia was absent. Absence of regional hyperkinesia, especially in anterior infarcts, was associated with a high mortality rate (13 of 19 patients [68%]). Remote asynergy, i.e., not adjacent to the infarct area and supposed to be related to another vascular region, was present in 17 of 98 patients (17%)--11 of 63 with anterior (17%) and 6 of 35 with inferior (17%) infarcts. Remote asynergy was present only in patients with multivessel CAD and was significantly related to a higher wall motion score (p less than 0.001), but not to enzymatic infarct size.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of full-dose heparin anticoagulation on the development of left ventricular thrombosis in acute transmural myocardial infarction

The incidence of left ventricular thrombosis after acute transmural myocardial infarction has been evaluated with two-dimensional echocardiography. To assess the preventive action of early anticoagulation with full-dose heparin, 90 patients, admitted within 5.2 +/- 4.6 hours after the onset of symptoms of their first episode of acute myocardial infarction (46 anterior and 44 inferior), were prospectively studied. Patients were randomly assigned either to therapeutic anticoagulation with heparin or to no anticoagulant therapy. Serial two-dimensional echocardiograms were recorded on the day of admission, the next day, days 4 to 7 and days 20 to 50 to detect left ventricular thrombus and to assess global left ventricular performance. On the first echocardiogram (10.3 +/- 8.0 hours after the onset of symptoms) no thrombus was visualized. In 44 patients with inferior myocardial infarction (23 receiving heparin and 21 not receiving heparin) no further left ventricular thrombus developed. In 46 patients with anterior myocardial infarction, 21 additional thrombi developed (45.6%) within 4.3 +/- 3.0 days after the acute event. Thrombus developed in 8 (38%) of 21 patients receiving heparin, compared with 13 (52%) of 25 patients not receiving heparin. This difference in ventricular thrombosis was not statistically significant (chi-square with the Yates correction = 0.76; NS). No difference was found between the subgroups in terms of clinical variables, infarct size, hemodynamic impairment, intensity of the inflammatory process and quantitative two-dimensional echocardiographic and cineangiographic left ventricular function. It is concluded that early anticoagulation with heparin reduced by 27% the incidence of left ventricular thrombus formation in anterior acute transmural myocardial infarction, and this relative risk reduction was not statistically significant when compared with findings in the untreated group.

Fibrin formation and platelet aggregation in patients with acute myocardial infarction: effects of intravenous and subcutaneous low-dose heparin

Fibrinopeptide A (FPA) and beta thromboglobulin (BTG) were measured in 42 patients with acute myocardial infarction (AMI) allocated on admission to one of three groups: 14 patients received a heparin bolus injection of 5000 IU intravenously followed by a 2-hour intravenous infusion (830 IU/hr) (group 1), 14 patients received a heparin bolus of 5000 IU subcutaneously (group 2), and the remaining 14 patients received no anticoagulant treatment (group 3). In group 1 the initially elevated FPA level of 5.8 +/- 1.8 ng/ml dropped to 2.0 +/- 1.5 ng/ml 30 minutes after the intravenous heparin bolus injection of 5000 IU (p less than 0.001) and returned to normal (1.9 +/- 0.8 ng/ml) in 8 of 14 patients. The initially elevated BTG level of 64 +/- 21 ng/ml did not change significantly during intravenous heparin treatment, whereas there was a rapid but only transitory increase in platelet factor 4, (PF4) from 25 +/- 9 to 74 +/- 16 ng/ml (p less than 0.01) after the intravenous heparin bolus. In group 2 the initial FPA of 5.0 +/- 2.3 ng/ml was similarly elevated as in group 1 and dropped to 2.7 +/- 1.7 and 3.3 +/- 1.5 ng/ml 2 and 4 hours after 5000 IU subcutaneously (p less than 0.05), whereas 6 and 8 hours after subcutaneous heparin bolus the mean FPA levels were 4.2 +/- 1.7 and 5.5 +/- 2.0 ng/ml and no more significantly different from the initial FPA values. BTG and PF4 did not change significantly after the subcutaneous heparin bolus. In group 3 the initially elevated mean FPA level of 4.9 +/- 2.4 ng/ml did not change significantly during the first 8 hours after admission, whereas the FPA level 24 hours after admission was 8.4 +/- 3.9 ng/ml and higher than the initial value (p less than 0.01). We conclude that heparin may reduce the elevated FPA level in plasma found in patients with AMI; however, neither subcutaneous nor intravenous heparin in a dosage frequently used is sufficient to consistently normalize the elevated rate of fibrin formation found in these patients.

A large pedunculated left ventricular thrombus with recurrent systemic thromboembolism in a young man

We present the case of a young man who has suffered from recurrent systemic thromboembolism since he developed an acute interior wall myocardial infarction at the age of 27. A large elongated, pendunculated left ventricular thrombus was found by two dimensional echocardiography and was successfully removed by open heart surgery.

Effect of early anticoagulation on the frequency of left ventricular thrombi after anterior wall acute myocardial infarction

To determine the effect of early anticoagulation on the incidence of left ventricular thrombi complicating anterior acute myocardial infarction (AMI), 82 consecutive patients admitted within 12 hours of symptom onset and with electrocardiographic changes consistent with anterior AMI were randomly assigned to 1 of 2 treatment groups. Group 1 patients received high-dose intravenous heparin to maintain the whole blood clotting time between 15 and 20 minutes, and commenced warfarin therapy within 48 hours. Group 2 patients received low-dose subcutaneous heparin and warfarin therapy if the peak creatine kinase level was more than 1,000 U/liter. Eighteen group 2 patients received warfarin, but none had a therapeutic prothrombin ratio within 5 days. The presence and morphologic characteristics of thrombus were assessed by serial 2-dimensional echocardiography. Thirty patients were excluded because AMI was not confirmed or because of technically unsatisfactory echocardiograms, death, surgery or, in group 1 patients, inadequate anticoagulation. Thrombi were identified in 29 of 52 patients (56%): in 14 of 25 group 1 patients (56%) and 15 of 27 group 2 patients (56%). Twenty-three thrombi formed within 3 days. Thrombi were protruding rather than mural only in 3 group 2 patients. The groups did not differ in baseline characteristics or in incidence, time of appearance or morphologic characteristics of thrombus (p greater than 0.05, beta for more than 25% reduction in incidence with group 1 treatment less than 0.10). Systemic embolism occurred only in 1 group 2 patient with mural thrombus.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of left ventricular thrombi by contrast-enhanced computed tomography and two-dimensional echocardiography

Contrast-enhanced computed tomography (CT) was compared with 2-dimensional echocardiography (2-D echo) for evaluation of left ventricular (LV) thrombus. Thirteen patients with coronary artery disease who had LV thrombus initially documented by 1 of the 2 techniques were then studied with the other technique. The findings of the studies were concordant in 8 of 13 patients, with a similar description of the presence, location and size of the LV thrombus and associated regional LV wall abnormalities. In 5 of 13 patients, the 2 techniques produced discordant data. Of these, 2 patients had false-negative results on 2-D echo owing to poor visualization of the LV apex; 1 patient had a false-positive result on 2-D echo related to misinterpretation of a prominent papillary muscle; 2 patients had false-negative CT results, 1 related to insufficient contrast infusion. The findings demonstrate that CT is a useful technique for evaluating LV thrombus, and may be particularly helpful when 2-D echo is technically limited or equivocal.

Incidence, timing and prognostic value of left ventricular aneurysm formation after myocardial infarction: a prospective, serial echocardiographic study of 158 patients

Serial 2-dimensional echocardiography was performed prospectively in 158 consecutive patients with first acute myocardial infarction (AMI) to determine the incidence of left ventricular (LV) aneurysm formation and the time course required for, and the clinical significance of, onset of LV aneurysm formation. Studies were performed throughout the first 5 days and after 3 months and 1 year. LV aneurysm was defined as an abnormal bulge in the LV contour during both systole and diastole. Eighty-four patients had anterior, 68 posterior and 6 anteroposterior AMI defined echocardiographically. During the study period, LV aneurysm was found in 35 of 158 patients (22%): in anterior AMI in 27, in posterior AMI in 6 and in anteroposterior AMI in 2. No new aneurysm developed after 3 months. Early aneurysm formation, during the first 5 days after AMI, was seen in 15 patients with anterior infarction. Twelve of these 15 (80%) died within 1 year (10 within 3 months), in contrast to 5 (25%) of the remaining 20 patients with LV aneurysm (p less than 0.05). Dyskinesia of the anterior wall in the acute stage usually resulted in aneurysm formation. Thus, LV aneurysm formation is seen in 22% of mostly anterior AMI and occurs within 3 months after AMI. Early aneurysm formation is associated with a high 3-month (67%) and 1-year (80%) mortality rate.