Prospective two-dimensional echocardiographic evaluation of left ventricular thrombus and embolism after acute myocardial infarction

Demonstration of Left Ventricular Thrombi with Real-time 3-Dimensional Echocardiography in a Patient with Cardiomyopathy

Two-dimensional echocardiography is a conventional tool to evaluate left ventricular thrombus but the use of real-time 3-dimensional echocardiography is not widespread. We report a 35-year-old man with unsuspected cardiomyopathy and a long history of both amphetamine and alcohol abuse. He presented with abdominal pain and right lower leg numbness and pain. Computed tomography revealed infarctions of the spleen and both kidneys, along with occlusion of the right femoral artery. Echocardiography demonstrated left ventricular systolic dysfunction and multiple large thrombi in the left ventricle. The thrombi had a specific dynamic pattern on real-time 3-dimensional echocardiography. The patient underwent surgical embolectomy of the right femoral artery and was anticoagulated. Two months later, the cardiac thrombi had totally disappeared.

Peak C-reactive protein concentration correlates with left ventricular thrombus formation diagnosed by contrast echocardiographic left ventricular opacification in patients with a first anterior acute myocardial infarction

BACKGROUND

Wall motion abnormality in the apical legion of the left ventricle (LV) with stagnant flow alone is not sufficient to identify patients at high risk for LV thrombus formation among those with first anterior acute myocardial infarction (AMI). The aim of this study was to identify the determinants of LV thrombus formation using contrast echocardiography.

METHODS AND RESULTS

In 75 patients with first anterior AMI, standard and contrast echocardiography was performed to detect LV thrombus. Although LV thrombus was found in 10 patients (13%) using standard echocardiography, it was found in 15 patients (20%) using contrast echocardiography. Apical stagnant flow was observed in 14 patients (93%) with LV thrombus. In addition, patients with LV thrombus had a higher peak C-reactive protein (CRP) concentration (18.2+/-4.3 vs 7.9+/-5.5 mg/dl, p<0.0001). In multivariate analysis, only peak CRP concentration was identified as an independent predictor of LV thrombus (p=0.02, odds ratio: 1.400, confidence interval: 1.040-1.884). The receiver-operating characteristics (ROC) analysis revealed the best cutoff value of a peak CRP concentration >10.7 mg/dl to identify patients with LV thrombus (sensivity 0.93, specificity 0.75, area under ROC curve 0.91).

CONCLUSIONS

The peak CRP concentration is a useful marker of patients with first anterior AMI who are at high risk for LV thrombus.

Incremental Value of Live/Real Time Three-Dimensional Transthoracic Echocardiography in the Assessment of Left Ventricular Thrombi

This is a case series on three adult patients who contain left ventricular (LV) thrombus and the incremental benefits of live/real time three-dimensional transthoracic echocardiography (3DTTE) in comparison to two-dimensional transthoracic echocardiography (2DTTE) in evaluating LV thrombi. These cases illustrate that 3DTTE is of additional benefit by demonstrating the following: (1) cropping of a single 3DTTE apical dataset may be enough to provide comprehensive assessment of the LV in a timely manner even without breath holding in a not fully cooperative patient (2) it identifies the exact point of attachment of the thrombus to the left ventricular wall, (3) helps to delineate the absence or presence of focal echolucent areas within thrombi indicative of the presence and extent of clot lysis, which may have potential therapeutic and prognostic implications, and (4) provides more accurate assessment of thrombus mobility which has prognostic indications.

Morphological Assessment of Left Ventricular Thrombus by Live Three-Dimensional Transthoracic Echocardiography

We report the usefulness of live three-dimensional transthoracic echocardiography (3DTTE) in the morphological assessment of a left ventricular thrombus. Using live 3DTTE, the thrombus could be easily viewed end-on and from the sides. In addition, by cropping the 3D images sequentially in transverse (horizontal or short axis), longitudinal (vertical or long axis), frontal, and oblique planes, the degree and extent of lysis within the thrombus, which represents an integral part of the clot-resolution process, could be comprehensively assessed. The site of attachment of the thrombus in the left ventricular apex and its morphology could also be fully evaluated in three dimensions by live 3DTTE.

Real-time three-dimensional echocardiography versus two-dimensional echocardiography in the diagnosis of left ventricular apical thrombi: preliminary findings

PURPOSE

Real-time 3-dimensional transthoracic echocardiography (RT-3D-TE) with real-time volume rendering (RTVR) offers multiple simultaneous views and spatial definition of intracardiac structures superior to that attainable by 2-dimensional transthoracic echocardiography (2D-TE). We hypothesized that RT-3D-TE would therefore improve identification of left ventricular apical thrombi (LVT).

METHODS

Patients were referred to our echocardiography laboratory over an 8-month period. Those diagnosed with a "suspicious" or "definite" LVT on the basis of 2D-TE images underwent RT-3D-TE on the same day. All 2D-TE, RT-3D-TE, and RTVR images were reviewed by 2 independent observers. RT-3D-TE findings were considered positive for LVT if LVT was visualized in both B-scan (apical orthogonal) and C-scan (short axis, with and without tilting angle) planes and on RTVR images, nondiagnostic (or suspicious) for LVT if it was not visualized in all planes, and negative for LVT if it was not visualized in any plane.

RESULTS

Thirty patients (19 men and 11 women) with a mean age (+/- standard deviation) of 52 +/- 13 years were enrolled. The interobserver agreement coefficient was 63% for 2D-TE interpretations of LVT and 93% for RT-3D-TE interpretations of LVT (p<0.05). The final interpretations by RT-3D-TE with RTVR were positive for LVT in 16 patients (53%), suspicious for LVT in 4 patients (13%), and negative for LVT in 10 patients (30%).

CONCLUSIONS

RT-3D-TE with RTVR offers dramatically clearer echocardiographic findings than does 2D-TE. In particular, RT-3D-TE is able to provide a clear diagnosis of LVT/non-LVT when 2D-TE images are merely suggestive of the disorder. Therefore, RT-3D-TE with RTVR, which is a clinically feasible alternative to 2-dimensional echocardiography, has great potential to positively affect the diagnosis, follow-up, and care of patients with suspected LVT.

[An elderly patients with ventricular aneurysm, thrombus in the aneurysm, and cerebral infarction 10 years after myocardial infarction]

A 75-year-old man had a 26-year history of hypertension and an 18-year history of effort angina pectoris. He suffered acute myocardial infarction at age 61. According to serial echocardiography, the initially hypokinetic segment of the left ventricular apex was transformed to an apical aneurysm over the course of 10 years (at age 71). Ten months later, a transient ischemic attack occurred, despite the administration of aspirin. At age 72, echocardiography revealed a hyperechoic lesion that was suspected to be a thrombus within the aneurysmal cavity. Cerebral infarction (right occipital lobe) occurred 13 years after myocardial infarction, at age 73. After warfarin therapy for 3 months, the thrombus-like echo in the left ventricular aneurysm disappeared.

Doppler-derived mitral deceleration time as an early predictor of left ventricular thrombus after first anterior acute myocardial infarction

BACKGROUND

The relation between left ventricular (LV) diastolic function and LV thrombus has not yet been fully investigated. The aim of this study was to determine whether early assessment of Doppler-derived mitral deceleration time (DT), a measure of LV compliance and filling, may predict LV thrombus formation after acute myocardial infarction.

METHODS AND RESULTS

Two-dimensional and Doppler echocardiographic examinations were performed in 98 consecutive patients (aged 57 +/- 12 years; 8 women) with first acute myocardial infarction. The patients were studied within 24 hours and at days 3, 7, 15, and 30 after arrival to the coronary care unit. Mitral flow velocities were obtained from the apical 4-chamber view with pulsed Doppler. LV thrombus was detected in 20 of 98 patients. Patients were divided into 2 groups according to LV thrombus formation: group 1 (n = 20) with thrombus and group 2 (n = 78) without thrombus. Mitral E-wave DT was significantly shorter in group 1 than group 2 (134 ms vs 175 ms; P <.001). Patients in group 1 had significantly larger LV end-diastolic and end-systolic volumes and a higher wall motion score index than patients in group 2 (133 +/- 39 mL vs 112 +/- 41 mL, P =.03; 83 +/- 34 mL vs 59 +/- 30 mL, P =.003; and 1.8 +/- 0.3 mL vs 1.5 +/- 0.3 mL, P =.007, respectively). The LV ejection fraction was significantly lower in group 1 than in group 2 (39% +/- 13% vs 48% +/- 12%; P =.004). In a multivariate regression analysis, mitral E-wave DT was identified as an independent variable related to development of LV thrombus (P =.04).

CONCLUSIONS

Doppler-derived mitral DT is superior to conventional clinical and 2-dimensional echocardiographic assessment in estimating the risk of left ventricular thrombosis after myocardial infarction.

Predictors of left ventricular thrombus formation in patients with anterior myocardial infarction: role of activated protein C resistance

BACKGROUND

Left ventricular mural thrombus formation is a well-recognised consequence of acute anterior myocardial infarction. The vast majority of left ventricular thromboses occur in patients with anterior myocardial infarction and depressed left ventricular function.

OBJECTIVE

To evaluate the factors predicting left ventricular thrombus formation in patients similar for left ventricular function and left ventricular score indexes.

METHODS

We evaluated 45 consecutive patients who met the inclusion criteria of anterior myocardial infarction resulting in apical, anterior or septal asynergy (akinesia, dyskinesia), without non-Q-wave myocardial infarction, dilated cardiomyopathy, or renal or hepatic dysfunction. Patients were divided into two groups: group I with, and group II without, left ventricular mural thrombus. The groups were compared for clinical, echocardiographic and hematologic parameters (activated protein C resistance (APC-R), protein S and antithrombin III).

RESULTS

Smoking and ACP-R were significantly greater in group I than in group II (P < 0.05 and P < 0.005 respectively). Multivariate regression analysis showed that APC-R was an independent risk factor for left ventricular thrombus formation in the patient group selected. Antithrombin III and protein S concentrations were not statistically different between two groups. All other clinical and echocardiographic characteristics of the patients were similar in both groups.

CONCLUSION

APC-R is an independent risk factor for left ventricular thrombosis in patients with anterior myocardial infarction resulting in septal or anterior and apical akinesia or dyskinesia.

Improved echocardiographic delineation of left ventricular thrombus with the use of intravenous second-generation contrast image enhancement

Transthoracic echocardiography is the most widely used diagnostic test for left ventricular (LV) thrombus, which must be distinguished from other intraventricular structures and image artifacts. To determine whether second-generation intravenous echocardiographic contrast agents provide better delineation of LV thrombus, we reviewed the results of 2-dimensional echocardiographic studies that were performed in 409 patients over a 1-year period to detect LV thrombus. Studies of 190 (46%) patients were interpreted as nondiagnostic for this purpose, of which 48 patients underwent an additional study after intravenous injection of 0.5 to 2 mL of human albumin microspheres within 1 to 4 days. In 43 (90%) of these 48 patients the contrast-enhanced study was definitive and diagnostic for either the presence or absence of an LV thrombus (P <.0001). Of the initial total of 409 patients, 81 had been studied at the bedside in intensive care units. The bedside studies were nondiagnostic for LV thrombus in 51 (63%) of these 81 patients. Of these 51 patients, 14 underwent additional imaging with contrast enhancement, and the contrast-enhanced images became diagnostic (P =. 004) in 11 (79%) of them. Thus intravenous contrast image enhancement improves the diagnostic yield of echocardiography in patients in whom initial images are nondiagnostic for LV thrombus.

Right Ventricular Infarction: Contribution of Echocardiography to Diagnosis and Management

Right ventricular infarction (RVI) is associated with nearly one third of patients who have inferior myocardial infarction (MI). The classic triad of hypotension, clear lung fields, and increased jugular venous pressure in the setting on inferior MI is highly suggestive of RVI. Direct visualization of the RV and left ventricular chambers on two-dimensional echocardiography allows early diagnosis by demonstration of predominant RV asynergy (akinesis plus dyskinesis), RV dilation, and decreased RV ejection fraction. The extent of RV involvement varies widely and correlates with outcome. Serial two-dimensional echocardiography and Doppler are also valuable in short- and long-term management, to detect complications, and to assess outcome.

Congestive cardiac failure (CCF) as a cause of fatal stroke and all cause death

BACKGROUND

Congestive cardiac failure (CCF) has been found to be a clinical risk factor for stroke in patients with non rheumatic atrial fibrillation.

AIMS

To study CCF as a risk factor for stroke deaths and all cause deaths in coronary heart disease (CHD).

METHODS

Case control study from a single cardiologist's practice: 370 deaths, 32 (9%) from stroke; controls of 160 and 370 consecutive patients for stroke deaths and all cause deaths respectively. Multivariate analysis using logistic regression.

RESULTS

A--Stroke deaths. Positive associations for CHD with CCF, hypertension; negative association for CHD without CCF. Patients with CHD and CCF were 7.4 times as likely to die from stroke as patients with CHD without CCF. B--All cause deaths. Positive associations for CHD or cardiomyopathy with CCF, atrial fibrillation, diabetes and hypertension; negative association for CHD without CCF. Patients with CHD and CCF were 6.1 times as likely to die from all causes as patients with CHD without CCF.

CONCLUSIONS

Many stroke deaths in patients with CHD and CCF may be cardioembolic in origin. A randomised controlled trial in such patients is indicated to see if anticoagulants can reduce the incidence of stroke.

Refractory Left Ventricular Failure Due to Large Left Ventricular Thrombus

Mural thrombi are common in patients with acute myocardial infarction and can cause refractory left ventricular failure as a rare complication. We report a case of large postinfarction ventricular thrombus resulting in left ventricular failure resistant to medical therapy. After echocardiographic diagnosis, thrombectomy and coronary bypass grafting were performed and the symptoms subsided.

Visualization of clear echocardiographic images with near field noise reduction technique: experimental study and clinical experience

BACKGROUND

With transthoracic echocardiography, it is sometimes difficult to obtain a clear image of the apical portion of the heart because of noise near the transducer. To reduce this artifact, we have developed a new technique (near field noise reduction, NFNR) based on the digital filtering by using radiofrequency signals. This technique may be useful for the accurate measurement of the wall thickness of the myocardium in the near field. The objectives of these studies were (1) to determine the accuracy of this new technique for the measurement of wall thickness in the experimental study and (2) to determine whether the improvement in the image quality in the apical portion can be obtained in the clinical setting by using the NFNR technique.

EXPERIMENTAL STUDY

By using the NFNR technique, we measured wall thickness of three kinds of phantoms (wall thickness 9.0, 14.0, and 21.0 mm) moving at various velocities (5 to 80 mm/sec) in the water bath with artifact produced by a single probe. It was difficult to obtain clear echocardiographic images of the phantom and measure its wall thickness because of the artifact. By using the NFNR technique, on the other hand, the same phantom was clearly imaged. It was possible to measure the wall thickness of each phantom at each moving velocity with the NFNR technique. Mean differences between the echocardiographic measurement and actual value of wall thickness in each phantom model (9.0, 14.0, and 21.0 mm) were 0.04 +/- 0.58 mm, 0.09 +/- 0.58 mm, and -0.02 +/- 0.24 mm, respectively.

CLINICAL STUDY

We studied 25 initial patients in whom the near field was not clearly imaged in apical views by conventional echocardiography because of near field noise. Apical four-chamber or two-chamber views were obtained with and without the NFNR technique. Two observers independently graded endocardial visualization for the 50 segments by using a three-point scale (0 = endocardium not seen, 1 = seen in part but not all of the segment, 2 = endocardium seen along entire segment). The mean segment score in the imaging with the NFNR technique was significantly higher than that without the NFNR technique (observer 1: 1.8 +/- 0.7 vs 1.2 +/- 0.8, p < 0.01; observer 2: 1.6 +/- 0.7 vs 1.2 +/- 0.8, p < 0.01).

CONCLUSIONS

The newly developed NFNR technique provides clear echocardiographic images and accurate wall thickness measurement in the experimental model even when it is difficult to obtain clear images because of the artifact. This new technique will be useful in the reduction of near field noise in the clinical setting.

Risk factors for in-hospital nonhemorrhagic stroke in patients with acute myocardial infarction treated with thrombolysis: results from GUSTO-I

BACKGROUND

Nonhemorrhagic stroke occurs in 0.1% to 1.3% of patients with acute myocardial infarction who are treated with thrombolysis, with substantial associated mortality and morbidity. Little is known about the risk factors for its occurrence.

METHODS AND RESULTS

We studied the 247 patients with nonhemorrhagic stroke who were randomly assigned to one of four thrombolytic regimens within 6 hours of symptom onset in the GUSTO-I trial. We assessed the univariable and multivariable baseline risk factors for nonhemorrhagic stroke and created a scoring nomogram from the baseline multivariable modeling. We used time-dependent Cox modeling to determine multivariable in-hospital predictors of nonhemorrhagic stroke. Baseline and in-hospital predictors were then combined to determine the overall predictors of nonhemorrhagic stroke. Of the 247 patients, 42 (17%) died and another 98 (40%) were disabled by 30-day follow-up. Older age was the most important baseline clinical predictor of nonhemorrhagic stroke, followed by higher heart rate, history of stroke or transient ischemic attack, diabetes, previous angina, and history of hypertension. These factors remained statistically significant predictors in the combined model, along with worse Killip class, coronary angiography, bypass surgery, and atrial fibrillation/flutter.

CONCLUSIONS

Nonhemorrhagic stroke is a serious event in patients with acute myocardial infarction who are treated with thrombolytic, antithrombin, and antiplatelet therapy. We developed a simple nomogram that can predict the risk of nonhemorrhagic stroke on the basis of baseline clinical characteristics. Prophylactic anticoagulation may be an important treatment strategy for patients with high probability for nonhemorrhagic stroke, but further study is needed.

Efficacy of high dose intravenous heparin for treatment of left ventricular thrombi with high embolic risk

OBJECTIVES

This study was performed to assess the efficacy of high dose intravenous heparin to treat mobile or protruding left ventricular thrombi as detected by serial echocardiography.

BACKGROUND

The presence of mobile and protruding left ventricular thrombi greatly increases the risk of arterial embolization, yet optimal therapy, be it thrombolysis, anticoagulation or surgical removal, has not been defined.

METHODS

Full dose heparin, 31,291 +/- 7,980 (mean +/- SD) IU/day, to prolong partial thromboplastin time to at least twice normal, was administered intravenously to 23 consecutive patients with 25 mobile and protruding thrombi. Patients were prospectively evaluated for hemorrhagic complications and embolic events during therapy. The presence or absence of thrombi and their size and characteristics were assessed by serial echocardiography.

RESULTS

In all 23 patients left ventricular thrombi decreased in size, with disappearance of the high risk features. The duration of high dose heparin infusion was 7 to 22 days (mean 14 +/- 4). Thrombus size was reduced from 3.9 +/- 2.6 to 0.16 +/- 0.38 cm2, and thrombus disappeared entirely in 19 (83%) of 23 patients. No embolic events were detected during treatment, and the only complication was an upper gastrointestinal hemorrhage that was successfully treated medically.

CONCLUSION

High dose intravenous heparin is a highly effective and safe treatment for completely resolving left ventricular thrombi with high risk features for embolization. Most such thrombi disappear completely within 1 to 3 weeks of this treatment without embolic or hemorrhagic complications.

Improved echocardiographic detection and characterization of left ventricular apical thrombi with a 5.0 MHz short-focus transducer

Transthoracic echocardiography is a frequently used technique for detecting ventricular thrombi. This study compares the usefulness of a 5.0 MHz short focal length transducer (5-short) with standard frequency (2.5 or 3.5 MHz) transducers for the detection of left ventricular thrombi. In addition, the effect of body habitus on study quality was evaluated. A consecutive series of 101 patients sent for echocardiographic imaging with the diagnosis of myocardial infarction, dilated cardiomyopathy, or recent suspected embolic event were imaged in the apical four-chamber, apical long-axis, and apical two-chamber views with a standard transducer and also with the 5-short. Out of this group, 16 apical thrombi were identified, six with the 5-short only, three with standard transducers only, and seven by both techniques. The areas of the seven thrombi detected by both transducers were consistently larger when measured on 5-short images compared with standard transducer images (4.6 +/- 2.3 vs 3.7 +/- 2.3 cm2, p = 0.02). In the three studies positive only with the standard transducers, the 5-short demonstrated only prominent trabeculae but no thrombus. The studies positive only with the 5-short had significantly smaller calculated thrombi areas than those visualized by the standard transducers (1.6 +/- 1.2 vs 4.2 +/- 2.1 cm2, p = 0.02). No thrombus was detected by either technique in a normally contracting left ventricular apex. There were significantly fewer studies having near-field artifact when performed by the 5-short compared with those performed with standard transducers (14/101 vs 40/101, p = 0.00004).(ABSTRACT TRUNCATED AT 250 WORDS)

Embolic potential, prevention and management of mural thrombus complicating anterior myocardial infarction: a meta-analysis

OBJECTIVES

The management of mural thrombus complicating acute anterior myocardial infarction remains controversial in part because of the small size of studies on this topic. We performed a meta-analysis of published studies to address three questions: 1) What is the embolic risk of mural thrombi after myocardial infarction? 2) What is the impact of systemic anticoagulation in reducing the embolic risk of mural thrombi? 3) What is the impact of systemic anticoagulation, thrombolytic therapy and antiplatelet therapy in preventing mural thrombus formation?

METHODS

Studies were identified by a computerized and manual search and were included if they were published in manuscript form in the English-language literature. Pooling of data was performed by calculating the Mantel-Haenszel odds ratio and an event rate difference by the method of DerSimonian and Laird.

RESULTS

The odds ratio for increased risk of emboli in the presence of echocardiographically demonstrated mural thrombus (11 studies, 856 patients) was 5.45 (95% confidence interval [CI] 3.02 to 9.83), and the event rate difference was 0.09 (95% CI 0.03 to 0.14). The odds ratio of anticoagulation versus no anticoagulation in preventing embolization (seven studies, 270 patients) was 0.14 (95% CI 0.04 to 0.52) with an event rate difference of -0.33 (95% CI -0.50 to -0.16). The odds ratio of anticoagulation versus control in preventing mural thrombus formation (four studies, 307 patients) was 0.32 (95% CI 0.20 to 0.52), and the event rate difference was -0.19 (95% CI -0.09 to -0.28). The odds ratio for thrombolytic therapy in preventing mural thrombus (six studies, 390 patients) was 0.48 (95% CI 0.29 to 0.79) with an event rate difference of -0.16 (95% CI 0.10 to -0.42), whereas for antiplatelet agents (two studies, 112 patients) the odds ratio was 1.43 (95% CI 0.04 to 56.8) with an event rate difference of 0.16 (95% CI -0.20 to 0.52).

CONCLUSIONS

This analysis supports the hypotheses that 1) mural thrombus after myocardial infarction poses a significantly increased risk of embolization, 2) the risk of embolization is reduced by systemic anticoagulation, and 3) anticoagulation can prevent mural thrombus formation. Thrombolytic therapy may prevent mural thrombus formation, but evidence for a similar benefit of antiplatelet therapy is lacking.

Echocardiography in the evaluation of cardiac sources of emboli: the role of transthoracic echocardiography

Cardioembolism is responsible for a significant number of systemic emboli including approximately 15% of all ischemic strokes. Transthoracic echocardiography has contributed to the understanding of cardioembolism and has been used to detect specific and potential cardiac sources of systemic emboli and risk stratify patients with specific clinical findings for subsequent cardiovascular events. Findings from transthoracic echocardiography indicate that stasis is an important prerequisite for intracardiac thrombosis while reversal of stasis and thrombolysis appear operative in embolism of existing thrombus. Transthoracic echocardiography allows a sensitive and specific noninvasive means to detect left ventricular thrombus, valvular vegetation, and intracardiac tumor, lesions that are directly responsible for cardioembolism. Transthoracic echocardiography can also detect lesions that could potentially contribute to cardioembolism but are not specific causes. Examples of these potential lesions include mitral valve prolapse, patent foramen ovale, and interatrial septal aneurysm. Finally, population-based studies and prospective clinical trials have indicated that the results of transthoracic echocardiography have predictive value for subsequent cardiovascular events and hence provide a means for stratification of patients at risk for cardioembolism. The latter is most notable for the group of patients with nonvalvular atrial fibrillation where left ventricular dysfunction and increased left atrial size are independent predictors for subsequent stroke.

Left ventricular thrombosis and arterial embolism in acute anterior myocardial infarction

To study left ventricular thrombus (LVT) formation and arterial embolism (AE), 106 consecutive patients with a first acute anterior myocardial infarction (AAMI) underwent two-dimensional echocardiography before discharge. Repeated assessments for detection of AE were performed. Patients were non-randomly allocated to either no heparin, low-dose heparin or high-dose heparin. LVT was found in 25 (26.9%) of 93 patients with technically satisfactory echocardiograms. Left ventricular (LV) wall motion impairment (P = 0.0017) and treatment with either heparin or low-dose heparin (P = 0.0019) were independent predictors of LVT formation. AE, all strokes, occurred in 10 patients (9.4%) and was strongly associated with high age (P = 0.0013). In conclusion, LVT and AE are frequent complications to AAMI. LV wall motion impairment predisposes for LVT and low-dose heparin seems not to prevent these complications.

Usefulness of transesophageal echocardiography in identifying small left ventricular apical thrombus

OBJECTIVES

The aim of this study was to determine whether transesophageal echocardiography could clarify the nature of equivocal echodense structures in the left ventricular apical region frequently found on transthoracic echocardiography by directing the ultrasound beam from the left ventricular base to the apex and achieving better image quality.

BACKGROUND

Transthoracic echocardiography often reveals an echogenic structure suggesting thrombus in the left ventricular apical region because of limited near-field resolution and echo vibration artifact in apical views.

METHODS

Thirty-six patients with coronary artery disease or dilated cardiomyopathy who had apical wall motion abnormalities and equivocal transthoracic echodense structures were studied with transesophageal echocardiography using special manipulation of the transesophageal probe for adequate imaging of the apical region. Left ventricular thrombus was defined when echogenic structures with a clearly delineated margin adjacent to but distinct from the endocardium were observed in at least two different tomographic views in the four-chamber and left ventricular long-axis views during both systole and diastole.

RESULTS

Left ventricular thrombus (mean size 1.3 +/- 0.7 cm2) was defined by transesophageal echocardiography in 19 (53%) of 36 patients with suspected thrombus on transthoracic echocardiography in the four-chamber or left ventricular long-axis view. Heavy trabeculation or extremely high echo reflection, or both, was observed in the apical region in 12 patients (33%). No extra structures in the apical region were found in five patients. In 19 patients with transesophageal echocardiographically defined thrombus, 6 patients (31%) experienced arterial embolic events before the transesophageal procedure. In contrast, none of 17 patients without transesophageal echocardiographically defined thrombi had systemic embolism (p < 0.03).

CONCLUSIONS

1) Transesophageal echocardiography is useful in identifying left ventricular apical thrombus in patients with unclear echogenic structures on transthoracic apical images; and 2) the high incidence of arterial embolism in patients with transesophageal echocardiographically detected left ventricular thrombus indicates the clinical importance of such thrombus.

From swirling to a mobile, pedunculated mass--the evolution of left ventricular thrombus despite full anticoagulation. Echocardiographic demonstration

We describe the unusual evolution of a left ventricular thrombus following acute anterior myocardial infarction despite adequate anticoagulation. Serial echocardiographic examinations demonstrated the evolution from swirling in the left ventricle through a solid apical mass gradually dislodging into a mobile, pedunculated mass that was removed surgically to prevent embolization. This report emphasizes the need to follow echocardiographically left ventricular thrombi during treatment with anticoagulants, and to identify morphologic changes that may predict embolization. This case suggests that left ventricular thrombectomy should be considered in selected patients in whom a very high-risk thrombus morphology is detected.

Ischemic stroke and intracranial hemorrhage following thrombolytic therapy for acute myocardial infarction: a risk-benefit analysis

Stroke is a potentially serious complication of acute myocardial infarction (AMI). In the prethrombolytic era, most strokes were attributed to cerebral embolism. On the basis of available information, the occurrence of stroke in the thrombolytic era appears to be less than in the prethrombolytic era. In the thrombolytic era, the occurrence of various forms of intracranial hemorrhage has increasingly been documented in addition to cerebral embolism, with intriguing features. In general, however, the delineation of specific stroke subtypes has been imprecise and must take into account factors that are unique to this setting. Age is a risk factor for both ischemic and hemorrhagic stroke. Potential risk factors for intracranial hemorrhage include hypertension, dosage of fibrinolytic agents, and prior neurologic disease. Potential causes of intracranial hemorrhage include combined fibrinolytic/adjunctive therapies, various cerebrovascular lesions, and head trauma. Existing data suggest that mortality related to stroke complicating AMI is on the decline as well. More research is needed in order to quantify precisely the occurrence and proportions of stroke subtypes, risk factors, and causes in order to define mechanisms and preventive measures.

Dilated cardiomyopathy with mitral regurgitation: decreased survival despite a low frequency of left ventricular thrombus

Ninety-one patients with dilated cardiomyopathy were studied by two-dimensional, pulsed, and color Doppler echocardiography (1) to detect and quantify mitral regurgitation (MR), (2) to record apical flow velocities in systole and diastole, and (3) to detect the presence of left ventricular thrombi. MR was detected in 57% of the patients and thrombi were present in 40%, but the occurrence of both MR and thrombus was rare (8%). Apical flow velocity was significantly higher throughout the cardiac cycle in the group with MR (diastole 15 +/- 7 vs 9 +/- 7 cm/sec; systole 29 +/- 12 vs 16 +/- 13 cm/sec; p less than 0.001 for both), accounting for the rarity of thrombi in this group. Follow-up data on 89% of the patients showed markedly decreased survival in the group with MR (22% vs 60% at 32 +/- 6 months, p less than 0.005), and this was evident even in patients with mild MR. Thus although MR is a noninvasively obtainable marker of a large subgroup of patients with dilated cardiomyopathy "protected" from left ventricular thrombus formation, it is a sensitive marker of decreased survival.

Natural history of left ventricular thrombi: their appearance and resolution in the posthospitalization period of acute myocardial infarction

A series of 198 consecutive patients with acute myocardial infarction were prospectively studied before hospital discharge and during 24.0 +/- 8.6 months of follow-up. A predischarge thrombus was found in 38 (31%) of 124 patients with anterior infarction but in none of 74 patients with inferior infarction (p less than 0.001). Early thrombolytic therapy in 34 patients did not decrease the rate of thrombus occurrence. Acute anterior infarction, ejection fraction less than or equal to 35% and apical dyskinesia or aneurysm (but not akinesia) were significantly related to the appearance of thrombus during hospitalization by stepwise logistic regression analysis. Echocardiographic follow-up of 159 patients for at least 6 months (mean 26.6 +/- 8.4) revealed that thrombus disappeared in 14 (48%) of 29. Disappearance of thrombus was related to predischarge apical akinesia (but not dyskinesia) and to warfarin therapy during the follow-up period. A new thrombus first appeared after hospital discharge in 13 of 130 patients, and in 7 of the 13 it resolved during further follow-up. Thus, 30% (13 of 42) of thrombi in these patients appeared after discharge from the hospital. Three factors were related to occurrence of new thrombi during the follow-up period: deterioration in left ventricular ejection fraction, predischarge ejection fraction less than or equal to 35% and ventricular aneurysm or dyskinesia. Systemic embolism occurred in six patients, all with a predischarge thrombus (p less than 0.001). Mobility of the thrombus was the only variable significantly related to subsequent embolic events (p = 0.001) by logistic regression analysis. Thus, the predischarge echocardiogram identifies patients with thrombus and those at highest risk of embolic events. It can indicate patients who are likely to have thrombus resolution and those at risk of developing a new thrombus after hospital discharge. Follow-up echocardiograms may help in guiding the length of long-term anticoagulant therapy. Four additional patients with a predischarge apical mobile thrombus (not part of the consecutive series) received thrombolytic therapy. In two of the four, lysis of thrombus was achieved without complications, but systemic embolism occurred in the other two, and proved fatal in one.