Intracardiac thrombi: Frequency,location, etiology,and complications: A morphologic review—Part IV

Intracardiac thrombus may develop as a consequence of multiple underlying cardiac disorders. Valvular heart disease, in particular, rheumatic mitral stenosis is frequently associated with intracardiac thrombus. Pant IV of this 5-part article on intracardiac thrombus focuses on the frequency and consequences of thrombus in valvular heart disease.     

Intracardiac thrombi in primary antiphospholipid syndrome: two case reports

We describe two patients who developed stroke and ischemia of the left lower limb, related to intracardiac thrombi, as the first manifestation of primary antiphospholipid syndrome (PAPS). Transesophageal echocardiography (TEE) revealed intracardiac thrombi as abnormal hyperechogenic, nonmobile masses, firmly attached to the left atrial appendage and the anterior part of the mitral annulus, respectively. Our patients received high-intensity oral anticoagulant therapy (INR 3.0–4.0), which resulted in the rapid disappearance of clinical symptoms, without subsequent recurrence of thromboembolic manifestations, and the disappearance of intracardiac thrombi on TEE. Our findings underscore that PAPS should be suspected in patients presenting with intracardiac thrombi, even if they have no previous history of thromboembolic disorders. Moreover, because intracardiac thrombi may precede other manifestations of PAPS, this finding in young patients without underlying heart disease should invoke a search for both antiphospholipid and anticardiolipin antibodies.     

Association of prothrombin gene mutation with sepsis in a preterm with multiple intracardiac thrombi

We report for the first time, a premature infant with multiple intracardiac thrombi and sepsis, who was heterozygous for the G20210A prothrombin gene variant. Anticoagulant treatment with low molecular weight heparin resulted in the complete disappearance of the thrombi. It may be suggested that prothrombin gene variant associated with sepsis, respiratory distress syndrome, and perinatal asphyxia, as well as other thrombophilic disorders, could be a risk factor for the development of neonatal thrombus.     

Transthoracic echocardiography for precardioversion screening during atrial flutter/fibrillation in young patients

BACKGROUND: Transthoracic echocardiography (TTE) is reliable for detection of thrombi in the left ventricle and right atrium, but not in the left atrial appendage. Therefore, transesophageal echocardiography (TEE) is routinely performed in adults prior to electric cardioversion for atrial flutter/fibrillation (AFF). Whether young survivors of congenital heart disease repair with AFF need routine TEE prior to electric cardioversion is unknown. HYPOTHESIS: Electric cardioversion for AFF is safe in survivors of congenital heart disease repair/palliation if an intracardiac thrombus is not suspected on TTE imaging. METHODS: This study reports the outcome of patients in a pediatric tertiary care cardiac unit where electric cardioversion was performed if no intracardiac thrombus was suspected on TTE. We performed a retrospective chart review of all patients treated with electric cardioversion for AFF at Children's Hospital of Michigan during 1997-2002. RESULTS: Of 35 patients who presented with 110 episodes of AFF requiring electric cardioversion during the study duration, 32 (age 3 months-49 years, median age 20.5 years, 104 AFF episodes) had previously undergone palliative surgery or repair of their congenital heart disease. Of these 32 patients, 18 were survivors of a Fontan palliation (for a single-ventricle variant) and the remaining 14 were survivors of other defects and repairs (septal defects, valve replacements, and tetralogy of Fallot). During 81% of the episodes, patients were receiving aspirin, warfarin, or heparin for anticoagulation at presentation. Transthoracic echocardiography was performed in 74 AFF episodes; of these, 10 TTE studies were suspicious for atrial thrombi. Transesophageal echocardiography confirmed the presence of a thrombus in 3 of these 10 patients. These patients received warfarin for 2 weeks and then underwent electric cardioversion. No thromboembolic events occurred immediately after or on follow-up in any patient. CONCLUSIONS: These findings suggest that TTE may be an effective imaging tool for precardioversion screening in young patients with AFF.     

Lead Thrombi Associated with Externalized Cables on Riata ICD Leads: A Case Series

St. Jude Riata family ICD leads are subject to an FDA class I recall due to insulation failure, cable extrusions, and a high rate of electrical failures. We present multiple cases of large intravascular thrombus formation adherent to externalized conductor cables on Riata leads. Our observations highlight a previously unknown risk of large or calcified thrombus formation involving externalized conductors. We suggest that these leads should be screened for thrombi prior to potential lead extraction to determine the safest approach. Serial echocardiography may help detect progressive thrombus formation. The role of systemic anticoagulation for prevention or treatment of these thrombi remains unclear.     

Successful lysis of right and left heart thrombus by tissue plasminogen activator.

Tissue plasminogen activator (t-PA) was administered to three patients with newly developed intracardiac thrombi. Cases 1 and 2 developed right heart thrombi after radiofrequency ablation for atrioventricular nodal reentrant tachycardia and case 3 had tachycardia-related cardiomyopathy and a left ventricular thrombus. In all three patients, the intracardiac thrombi were successfully eliminated following t-PA therapy without major bleeding complications. These observations suggest that t-PA is effective in lysing new thrombus complicating radiofrequency ablation or heart failure and may be the therapy of choice in these conditions. Cathet. Cardiovasc. Intervent. 49:91-96, 2000.     

Intracardiac thrombosis diagnosed by echocardiography in childhood: predisposing and etiological factors

Eleven cases of intracardiac thrombi caused by different factors including protein-C deficiency are presented for discussion of the etiology and predisposing factors of intracardiac thrombi during infancy and childhood, and to stress the importance of protein-C deficiency as an etiological factor. Thrombi were localised in the left heart in five patients and right heart in five patients. One patient had both-sided thrombi. Four of our patients had dilated cardiomyopathy, one had mitral valve hypoplasia, and one had pulmonary valvar stenosis as the predisposing factors for thrombus formation. In three patients whose cardiac anatomies were completely normal, we determined protein-C deficiency as an etiological factor of thrombus formation. One of these had congenital protein-C deficiency and the other two had acquired temporary protein-C deficiency due to sepsis. In conclusion we recommend that protein-C deficiency should be investigated as an etiological factor in all cases of intracardiac thrombi irrespective of whether or not another predisposing factor is identified.     

Treatment of massive cardiac thrombi in a patient with protein C and protein S deficiency.

Myocarditis and dilated cardiomyopathy is characterized by dilatation of all four cardiac chambers and decreased systolic function of the heart, especially in the left ventricle. In this report we presented a patient with myocarditis or dilated cardiomyopathy and deficiency of protein C and protein S with biventricular multiple intracardiac thrombi. Standard heparin infusion and acetyl salicylic acid was begun. On the 10th day of hospitalization the right ventricular thrombus disappeared, and on the 24th day all thrombi in the left ventricle disappeared. During the treatment we did not observe any complication such as hemorrhagia or embolism. We think that patients with dilated cardiomyopathy or myocarditis should be evaluated for hemostatic disorders, and should be anticoagulated if any of these disorders are presented.     

Three-dimensional echocardiographic evaluation of the Fontan conduit for thrombus

Introduction: Total caval pulmonary connection (Fontan circuit) is the final common pathway for the palliation of single ventricle congenital heart disease. Flow within the Fontan circuit results in an environment that is prone to thrombus formation putting the patient at risk for pulmonary and/or systemic embolus. To prevent these problems, patients are placed on antithrombotic therapy and periodically evaluated for thrombus within the conduit. Two‐dimensional (2D) echocardiography, although commonly used to evaluate these patients, has been shown to have limited ability in accurately identifying thrombi within the Fontan conduit. The diagnosis of intracardiac thrombi has been augmented by three‐dimensional (3D) echocardiography and the patients in this series were evaluated with 3D imaging (3D transthoracic echocardiography and/or 3D transesophageal echocardiography) to determine if thrombi could be detected or excluded within the Fontan conduit. To the author's knowledge, this constitutes the first case series describing the use of 3D echocardiography to evaluate the Fontan conduit for thrombus. Methods: The four patients described in this case series underwent 3D echocardiography to evaluate the Fontan conduit for a suspected or potential thrombus. Results: The Fontan conduit was imaged and thrombi were felt to be documented or excluded in all four patients with 3D echocardiography. Conclusions: Three‐dimensional echocardiography may enhance the ability to detect or exclude thrombi within the Fontan conduit. Further studies are needed to determine if this will prove to be an effective and reliable technique in evaluating the Fontan conduit for thrombus. (Echocardiography 2012;29:363‐368)     

Valvular heart disease in Antiphospholipid antibody syndrome: Isolated Tricuspid stenosis

Antiphospholipid antibody syndrome (APLS) is a rare disorder characterized by a hypercoagulable state. Manifestations include arterial or venous thrombosis, recurrent fetal wastage, coronary artery disease, valvular heart disease, dilated cardiomyopathy, pulmonary artery hypertension, and intracardiac thrombus. Most commonly mitral valve is affected followed by aortic and then tricuspid valve. In this report, a rare case of spontaneous aortic thrombosis with tricuspid stenosis uncomplicated by other valve lesions is presented with clinical and echocardiographic studies and computed tomographic images.     

Intracardiac thrombi: Frequency,location, etiology,and complications: A morphologic review—Part II

Intracardiac thrombus is a frequent finding at necropsy. Various cardiac disorders have been associated with its presence. Part II of this 5-part article focuses on atherosclerotic coronary heart disease (myocardial infarction) as an etiology for intracardiac thrombus.     

Intracardiac Thrombi in Acute Myeloid Leukemia: An Echocardiographic and Autopsy Correlation

Two-dimensional echocardiography is the primary diagnostic imaging modality for the evaluation of cardiac masses. We describe an adult male suffering from acute myeloid leukemia who was detected to have right atrial and right ventricular mass on echocardiography. Based on the clinical data metastasis, coincidental primary cardiac tumor, vegetation, and thrombi were considered as possible differential diagnosis. Chemotherapy for acute myeloid leukemia failed and patient succumbed to septicemia. Later, clinical autopsy confirmed the diagnosis of intracardiac thrombi. Occurrence of intracardiac thrombi in acute myeloid leukemia is extremely rare. This report also emphasises the importance of histopathological or clinical autopsy examination of the mass in certain clinical scenario with diagnostic dilema. (Echocardiography 2010;27:E4-E8)     

Acute intermediate-risk pulmonary embolism with right-sided free-floating intracardiac thrombus, systemic inflammatory reaction syndrome, multiple organ dysfunction syndrome, disseminated intravascular coagulation and acute ischaemia of a limb

A case of a 64 year-old woman admitted to ICCU because of severe dyspnoea and oedema of left lower limb is presented. We diagnosed coincidence of acute pulmonary embolism with right-sided free-floating heart thrombi, systemic inflammatory reaction syndrome, multiple organ dysfunction syndrome, disseminated intravascular coagulation and acute ischaemia of the right lower limb. Due to atypical clinical presentation therapeutic strategies were discussed with ZATPOL registry coordinator. The patient was treated pharmacologically, underwent cardiosurgical evacuation of right-sided intracardiac thrombus and lower limb amputation. At follow up visit 6 months after discharge from hospital she was in good general condition with no complaints.     

Massive obliterative right heart thrombus presenting with near‐syncope

Intracardiac thrombi are commonly encountered as a complication of a recent myocardial infarction, heart failure, atrial fibrillation, or intracardiac devices. The prevalence of atrial thrombi in the absence of these risk factors is not well‐described, but seems to be low. We present a case of a 51‐year‐old man with a massive mobile thrombus in the right heart extending through the tricuspid valve, diagnosed on echocardiography after presenting with a presyncopal episode.     

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.     

Intracardiac thrombi: Frequency,location, etiology,and complications: A morphologic review—Part III

Intracardiac thrombus may develop as a consequence of multiple underlying cardiac disorders. Left ventricular (LV) aneurysm following acute myocardial infarction has been associated with intra-aneurysmal thrombus and emboli. Part III of this 5-part article on intracardiac thrombus focuses on the frequency and consequence of thrombus associated with LV aneurysm.     

Immediate anticoagulation for intracardiac thrombus in acute cardioembolic stroke.

To assess the efficacy of immediate anticoagulation therapy on intracardiac thrombus formation in acute cardioembolic stroke, serial two-dimensional echocardiographic examinations were performed in 25 patients with acute cardioembolic stroke. Anticoagulation therapy was commenced within two days of onset in 7 patients (group A) but not in 18 patients (group B). Appearance or enlargement of intracardiac thrombi were not detected in group A but were noted in 7 patients (39%) of group B. Recurrence of systemic embolism was demonstrated in 3 patients (17%) of group B. There were no serious hemorrhagic complications in either group. Immediate anticoagulation could, therefore, be effective in preventing intracardiac thrombus formation and the consequent recurrence of systemic embolization in acute cardioembolic stroke. Because the study was preliminary and not randomized, further randomized study is desirable to establish the efficacy of immediate anticoagulation therapy.     

2-dimensional echocardiographic diagnosis of an intracardiac thrombus in children

Eight cases of intracardiac thrombi in infants and children were compiled in a cooperative study involving five paediatric cardiological centres. Two babies were hospitalised for cardiac failure due to a severe supraventricular arrhythmia. Two-dimensional echocardiography (2D echo) showed a left atrial thrombus which disappeared after anticoagulant therapy. The third case was unusual: 2D echo performed 4 months after a Senning operation for complete transposition of the great arteries showed stenosis of the pulmonary venous canal and a thrombus above the stenosis: the mass was echogenic, rounded, of variable density and in contact with the pulmonary veins. These findings were confirmed at autopsy. The fourth case was a 34 month old child with Fallot's triad in whom 2D echo showed a right ventricular thrombus, confirmed at surgery. The four remaining cases were thrombi detected in patients with congestive cardiomyopathy. The thrombus was adherent to the left ventricular lateral wall or apex. Two of these thrombi disappeared after anticoagulant therapy, one of which after hemiplegia. 2D echo is a useful tool for the diagnosis and surveillance of intraatrial or intraventricular thrombi. Intraatrial thrombi may be due to supraventricular arrhythmias in children; intraventricular thrombi are usually seen in association with poor left ventricular contractility. The diagnosis of thrombosis should lead to institution of anticoagulant or even fibrinolytic therapy in order to avoid systemic embolism.     

Observations on detecting left ventricular thrombus with two dimensional echocardiography: emphasis on avoidance of false positive diagnoses

Observations made in detecting left ventricular thrombus with two dimensional echocardiography in 25 patients are reviewed. In 20 patients thrombus was documented on angiography, surgery, postmortem examination or serial two dimensional echocardiographic findings; in the remaining five patients two dimensional echocardiographic findings of thrombus were unequivocal. In all 25 patients wall motion abnormalities ranging from hypokinesia to frank dyskinesia were present at the site of the thrombus. Twenty-three patients had an apical thrombus; two had thrombus adjacent to the inferior wall. Clear delineation of the endocardium and thrombus margin was considered essential to the correct diagnosis of thrombus. Both intracavitary motion of the thrombus margin and a layering effect were noted infrequently although they were of benefit in identifying an intracardiac mass as thrombus. In addition, serial evaluations were helpful in establishing the correct diagnosis.False positive diagnoses can be minimized if one understands certain technical limitations of this method and correctly identifies apical structures that are not thrombi. Axial and lateral resolution problems inherent with this technique can produce intracavitary echoes that may simulate thrombi. In addition, normal or pathologic structures at the apex may also simulate thrombi. These structures include the papillary muscles, muscular trabeculae, chordal structures and tangential information from normal myocardium. Varying the sector orientation or acoustic window, or both, will aid in correctly identifying these structures and distinguishing them from left ventricular thrombi.     

Intracardiac mobile thrombus and D-dimer fragment of fibrin in patients with mitral stenosis

OBJECTIVE--To investigate the relation between intracardiac thrombus and blood coagulability in patients with mitral stenosis. DESIGN--Prospective study. Cross sectional echocardiography and plasma concentrations of the D-dimer fragment of fibrin were used concurrently to detect intracardiac thrombus in patients with mitral stenosis. SETTING--Department of Medicine, National Cardiovascular Centre, Osaka, Japan. PATIENTS--63 patients with mitral stenosis. None of them had been receiving any anticoagulants or antiplatelet agents. MAIN OUTCOME MEASURES--Plasma concentrations of D-dimer in patients with a mobile intracardiac thrombus, those in patients with a non-mobile intracardiac thrombus, and those in patients without an intracardiac thrombus. RESULTS--A mobile intracardiac thrombus was found in 10 patients and a non-mobile thrombus in eight. The remaining 45 patients had no intracardiac thrombi. Plasma concentrations of D-dimer in the 10 patients with a mobile thrombus were all greater than 300 ng/ml (mean 983.3, 95% confidence interval 498.9 to 1467.7 ng/ml) and they were significantly higher than those in the patients with a non-mobile thrombus (226.2, 33.6 to 418.8 ng/ml) and the patients without an intracardiac thrombus (147.2, 110.4 to 184 ng/ml). CONCLUSIONS--A high plasma concentration of D-dimer seemed to reflect a hypercoagulable intracardiac state and may be a helpful indicator of the possible presence of mobile intracardiac thrombus in patients with mitral stenosis.