Related Articles

An atrial thrombus is a relatively common echocardiographic finding in patients with mitral valve stenosis (MVS) and atrial fibrillation (AF). However, a “ball thrombus” or floating thrombus in the left atrium is a rare and specific entity associated with MVS. A 24-year-old woman with rheumatic MVS presented with complaints of progressive dyspnea and inferior limbs edema that began 23 days earlier after a caesarean operation for stillbirth carried out at 8 months of pregnancy. At the time of hospitalization, she was in New York Heart Association functional class III and the ECG showed sinus rhythm. Transthoracic color-flow Doppler echocardiography revealed a thick, stenotic mitral valve with a valvular area of 0.9 cm2, and an echogenic large left-atrial mass diagnosed as a free-floating left-atrial thrombus that was corroborated by transesophageal echocardiography. She refused surgery and was treated medically, and low molecular weight heparin (LMWH) (enoxaparin 80 mg/12 h) was given for 14 days and was discharged uneventfully on coumarin. Two days before discharge, a transthoracic and transesophageal ecocardiography showed disappearance of the ball thrombus uneventfully leaving spontaneous echo contrast inside the left atrium. To the best of our knowledge, this is the first case showing disappearance of a giant left atrial ball thrombus with LMWH treatment in a patient with severe MVS during sinus rhythm associated with pregnancy.

Introduction

Left atrial free floating ball thrombus is a relatively rare event, especially without mitral valve disease.

Case presentation

A 61-year-old Turkish man was admitted to our hospital with a thrombus mass in his left atrium. Five months earlier, he had undergone right bilobectomy and superior bronchoplasty due to squamous cell carcinoma in the lung. The patient had no evidence of cardiac disease except atrial fibrillation and there were no defined embolizations. The thrombus mass was surgically removed. The patient was discharged from hospital on the sixth postoperative day.

Conclusion

Surgery with cardiopulmonary bypass is a safe method for treatment. The patient should be medicated with warfarin, especially in the presence of atrial fibrillation.

Left atrial thrombi were shown by two-dimensional echocardiography in three patients with mitral valve disease and neurological symptoms. In two patients the atrial thrombi had probably been the source of a previous cerebrovascular embolus. In the third, two-dimensional echocardiography detected the development of a recent ball-valve thrombus in the left atrial cavity, which caused intermittent obstruction and syncope. Echocardiographic findings were correlated with anatomical and histological data in all three patients. The spatial orientation provided by the multiple imaging planes of two-dimensional echocardiography permitted correct estimates of the size and position of the thrombus, and this mode was superior to the standard M-mode technique for non-invasive imaging of thrombus. Despite limitations of technique and resolution, the information provided by ultrasound can be extremely helpful in the management of patients. Ultrasonic screening (particularly the two-dimensional mode) is to be recommended in patients with neurological symptoms and clinical evidence of cardiac disease or arrhythmia.

Images

In addition to a typical pattern indicative of mitral stenosis, the M-mode echo-cardiogram of a patient with mitral valve disease revealed a broad band of dense echoes within an enlarged left atrial cavity that was suggestive of an intraatrial thrombus. Subsequent cross-sectional echocardiography demonstrated a globular cluster of echoes inside the left atrial cavity, thus corroborating our interpretation of the M-mode recording. When open mitral commissurotomy was performed, a large, partially calcified thrombus was found protruding from the posterior wall and left atrial appendage into the atrial cavity. Postoperative M-mode and cross-sectional echocardiography did not show the previously noted abnormal echoes within the left atrium.

A 20-year-old woman had received a 22-mm Lillehei-Kaster prosthesis at the age of 16 for progressive mitral valve stenosis. She was asymptomatic for 4 years, when dyspnea on exertion, orthopnea and paroxysmal nocturnal dyspnea recurred. Operation was undertaken and a thrombus of recent origin was found extending from the posterior aspect of the prosthetic ring to the posterior left atrial wall. The sewing skirt was covered with neoendothelium and the valve orifice was not compromised; however, the hinge mechanism on the ventricular surface was overgrown with a dense fibrotic pannus that limited the normal 80° excursion of the tilting disc to 15°. This marked limitation of disc motion produced the equivalent of severe mitral stenosis. The Lillehei-Kaster valve was excised and replaced with a #27 Björk-Shiley prosthesis. The patient improved, and she remains asymptomatic 1 year after surgery.

Objective—To assess the relative merits of transthoracic and transoesophageal echocardiography before balloon dilatation of the mitral valve.

Design—Transthoracic and transoesophageal echocardiograms were prospectively performed in 35 patients being considered for balloon dilatation of the mitral valve. Echocardiograms were analysed for image quality, the assessment of valve morphology, the detection of left atrial thrombus, and the assessment of mitral regurgitation and other valvar pathology.

Patients—35 consecutive patients with symptomatic dominant mitral stenosis.

Interventions—30 eventually underwent balloon dilatation of the mitral valve by the Inoue technique. Five patients had mitral valve replacement.

Main outcome measures—Echocardiographic and surgical detection of left atrial thrombus and successful, uncomplicated balloon dilatation of the mitral valve.

Results—Left atrial thrombus was detected in 1/35 patients by transthoracic studies compared with 6/35 from transoesophageal studies. Otherwise both techniques gave comparable results. Thrombus was confirmed at mitral valve replacement in five patients. Successful dilatation of the mitral valve was performed in 30 patients.

Conclusions—Transthoracic echocardiography is a useful screening procedure but transoesophageal echocardiography is mandatory before balloon dilatation of the mitral valve for the detection of left atrial thrombus.

Background. The discovery of a large left atrial mass through echocardiography obliges the clinician to perform a differential diagnosis to distinguish tumor from thrombus. The neovascularization of the mass could be helpful to predict the type of the malformation and whether it is in favour of a vacular tumour rather than a thrombus . Observation. A 43-years-old man who had no cardiac antecedent reported that he have had dyspnea and palpitation since 10 months. The cardiac auscultation, revealed an irregular rhythm with diastolic murmur at the apex. The electrocardiogram showed an atrial fibrillation. The transthoracic echocardiography revealed a severe mitral stenosis with a huge left atrial mass, confirmed through transesophageal echocardiography. After 4 weeks of an efficient anticoagulant treatment, the mass was still persistent in the echocardiography. So we decided to resect the mass and to achieve a mitral valve replacement. The preoperative coronarography showed neovascularization among the mass and fistula from the circumflex artery. Considering the characteristic of the mass (neovascularization and resistance to anticoagulant), we strongly suspected a vascular tumor especially myxoma, but the histological exam revealed an organized thrombus. Conclusion. Coronary neovascularization is a specific sign for left atrial thrombus in mitral stenosis, but surgery is the best way to confirm diagnosis.

A group of 111 patients with mitral valve disease was studied by M-mode and two-dimensional echocardiography. Five left atrial thrombi were demonstrated, two of which had probably been the source of previous embolic events. Two-dimensional echocardiography was superior to M-mode in providing spatial orientation. Using multiple cross-sections the exact localisation and the size of the thrombus formation could be estimated. Thrombus localisations at the upper, lateral, and septal atrial walls, normally inaccessible to the single-beam technique, were successfully imaged. Even two-dimensional echocardiography, however, constitutes an imperfect method. By comparison with the findings at surgery only one-third of confirmed thrombi could be detected non-invasively. According to their localisation seven clots in the appendage were missed by the ultrasound method. One further thrombus fixed to the upper left atrial wall near the entrance of the upper pulmonary veins was also undetected by echocardiography. Despite these limitations, the information provided by echocardiography can be most helpful in patient management. M-mode, in combination with two-dimensional echocardiography, is therefore recommended in all patients with mitral stenosis before diagnostic or therapeutic procedures are undertaken.

Images

Background

Left atrial thrombi are mostly related to mitral valve disease. The differential diagnosis of clots and myxomas in the left atrium is mostly based on echocardiography. Infection of intracardiac thrombi is extremely rare and mostly reported in ventricular clots or aneurysms following myocardial infarction.

Case presentation

We present the case of a 65 year old female with a history of mitral valve disease and chronic atrial fibrillation who suffered repeated embolic strokes and a giant infected clot in the left atrium. Although the patient underwent prompt surgery with removal of the clot and valve replacement the complication of septic emboli to the CNS led her to death. To the best of our knowledge this is the second report of an infected left atrial thrombus.

Conclusion

The case is a representative example of a neglected and undertreated patient with catastrophic consequences. Anticoagulant therapy in patients with mitral valve disease and atrial fibrillation should be applied according the currently available guidelines and standards in order to avoid analogous paradigms in the future. Mitral valve substitution should be considered in patients with mitral valve disease presenting thromboembolic complications. Surgery should be considered as the treatment of choice in cases of organized left atrial thrombus and suspected tumor or infected mass.

A left atrial thrombus is most often associated with atrial fibrillation and/or rheumatic mitral stenosis. It is very infrequently detected in the presence of sinus rhythm. The present report describes the case of a 66-year-old woman who presented with a stroke and was subsequently found to have two potential sources of embolization, including a vegetation on the native aortic valve, with associated severe aortic insufficiency, and a left atrial appendage thrombus despite being in sinus rhythm. To the authors’ knowledge, the present report is the first to describe a left atrial thrombus in sinus rhythm associated with aortic valve endocarditis.

A 63-year-old female was presented to emergency room with an abdominal pain. The patient had moderate mitral valve stenosis and atrial fibrillation. Abdominal computed tomography revealed right renal infarction. Transthoracic echocardiography showed a large mobile mass in the left atrium. Transesophageal two-and three-dimensional echocardiography showed a large mobile ovoid mass with a narrow stalk attached to the left atrial septum. It was thought to be a myxoma rather than thrombus. Anticoagulation with heparin was continued. When the operation was performed, there was no mass in the left atrium. It must be a thrombus and melt away.

Intracardiac thrombus during cardiopulmonary bypass (CPB) with full heparinization is very rare but fatal. A 60-year-old woman was scheduled for aortic and mitral valve repairs with a maze procedure for mixed aortic and mitral valvular heart disease with atrial fibrillation. Preoperative transthoracic echocardiography and cardiac computed tomography showed moderate aortic regurgitation and moderate mitral stenosis with regurgitation. There was no intracardiac thrombus. Aortic and mitral valve repairs with the maze procedure were successfully performed without unexpected events. During CPB weaning, a mobile hyper-echogenic mass in the left atrium was detected on transesophageal echocardiography. After cardiac arrest, it was surgically removed. On completion of the operation, weaning from CPB was accomplished uneventfully. The patient fully recovered and was discharged from the intensive care unit on her third postoperative day.

Occurrence of bioprosthetic valve thrombosis less than a year after replacement is very uncommon. Here, we describe a case of a 57 year old male, who presented 10 months after receiving a bioprosthetic mitral valve replacement with a two week history of dyspnea on exertion, worsening orthopnea and decreased exercise tolerance. Echocardiography revealed severe mitral regurgitation (MR), thrombosis of the posterior mitral leaflet, left atrial (LA) mural thrombus and a depressed left ventricular ejection fraction of twenty-five percent. Given severe clot burden and decompensated heart failure (New York Heart Association - NYHA class III) repeat sternotomy was done to replace the bioprosthetic mitral valve and remove LA mural thrombus. MR was resolved postoperatively. This brief report further reviews promoting factors, established guidelines and management strategies of bioprosthetic valve thrombosis.

Left atrial appendage (LAA) occlusion is a treatment strategy to prevent blood clot formation in atrial appendage. Although, LAA occlusion usually was done by catheter-based techniques, especially percutaneous trans-luminal mitral commissurotomy (PTMC), it can be done during closed and open mitral valve commissurotomy (CMVC, OMVC) and mitral valve replacement (MVR) too. Nowadays, PTMC is performed as an optimal management of severe mitral stenosis (MS) and many patients currently are treated by PTMC instead of previous surgical methods. One of the most important contraindications of PTMC is presence of clot in LAA. So, each patient who suffers of severe MS is evaluated by Trans-Esophageal Echocardiogram to rule out thrombus in LAA before PTMC. At open heart surgery, replacement of the mitral valve was performed for 49-year-old woman. Also, left atrial appendage occlusion was done during surgery. Immediately after surgery, echocardiography demonstrates an echo imitated the presence of a thrombus in left atrial appendage area, although there was not any evidence of thrombus in pre-pump TEE. We can conclude from this case report that when we suspect of thrombus of left atrial, we should obtain exact history of previous surgery of mitral valve to avoid misdiagnosis clotted LAA, instead of obliterated LAA. Consequently, it can prevent additional evaluations and treatments such as oral anticoagulation and exclusion or postponing surgeries including PTMC.

A 74 year old woman with mixed mitral valve disease presented with episodes of loss of consciousness and fainting. The attacks were noted to be closely related to posture, especially crouching, and this, with the clinical finding that the radial pulse disappeared before she lost consciousness, suggested the diagnosis of a ball valve thrombus. Cardiac catheterisation confirmed the diagnosis but was followed by a fall in blood pressure necessitating emergency surgery. The only position in which the circulation could be maintained was the right lateral, with steep head down tilt, and left femoro-femoral cardiopulmonary bypass had to be established in this position. Operation confirmed the presence of a ball valve thrombus and the patient recovered uneventfully.

Images

A 76-year-old woman presented with a six-day history of pleuritic pain, dyspnea and a swollen, tender left calf. She was dyspneic, tachypneic and tachycardic (heart rate 109 beats/min), with decreased oxygen saturation (83%) and a partial pressure of oxygen of 9 kPa. Her blood pressure was 119/79 mmHg, and she had elevated jugular venous pressure (11 mmHg). A computed tomographic pulmonary angiogram revealed extensive bilateral pulmonary artery thrombi and an ultrasound confirmed a lower limb thrombus. Echocardiography demonstrated a dilated right ventricle with pulmonary artery hypertension (75 mmHg) and a free-floating thrombus of 1.5 cm × 4 cm, which ricocheted across the right ventricular outflow tract from the tricuspid to the pulmonary valve. The left ventricle was underfilled and hyperdynamic. Following thrombolysis, the patient’s clinical status improved. Echocardiography revealed improved biventricular function, no residual right ventricular thrombus, and pulmonary artery pressure normalization. The present case demonstrates the usefulness of echocardiography in submassive pulmonary embolus risk stratification and management.

We describe an unusual sequela of mitral valve replacement in a 50-year-old woman who had undergone a closed mitral commissurotomy in 1975. She was admitted to our hospital because of mitral restenosis in November 1993, at which time her mitral valve was replaced with a mechanical prosthesis. On the 8th postoperative day, the patient developed symptoms of heart failure; transesophageal echocardiography revealed dissection and rupture of the left atrial wall. At prompt reoperation, we found an interlayer dissection and rupture of the atrial wall into the left atrium. We repaired the ruptured atrial wall with a prosthetic patch. The postoperative course was uneventful, and postoperative transesophageal echocardiography showed normal prosthetic valve function and no dissection.

Images

OBJECTIVE--To determine the value of transoesophageal echocardiography in the assessment of selected patients at risk of cardiogenic embolism or after it. DESIGN--Prospective comparison of the results of transoesophageal and transthoracic echocardiography. Transoesophageal echocardiography was performed with a 5 MHz single plane phased array transducer. SETTING--University teaching hospital. PATIENTS--100 patients referred for transoesophageal echocardiography after a cerebral ischaemic event or peripheral arterial embolism (n = 63), before percutaneous balloon dilatation of the mitral valve (n = 23), or before electrical cardioversion of atrial fibrillation (n = 14). RESULTS--Transthoracic echocardiography showed potential sources of embolism in four patients including left ventricular thrombus in two patients (with one false positive), left atrial appendage thrombus (n = 1), and patent foramen ovale (n = 1). Transoesophageal echocardiography showed 59 potential embolic sources in 45 patients including left atrial spontaneous echo contrast (n = 33), left atrial appendage thrombus (n = 13), left ventricular thrombus (n = 5), patent foramen ovale (n = 3), left ventricular spontaneous echo contrast (n = 2), mitral valve prosthesis thrombus (n = 1), mitral valve prolapse (n = 1), and pronounced aortic atheroma (n = 1). Transoesophagal echocardiography showed potential embolic sources in 36/53 (68%) patients with atrial fibrillation compared with 9/47 (19%) patients in sinus rhythm. Percutaneous balloon dilatation of the mitral valve was performed without embolic complications in 18 patients without left atrial thrombi and in three patients with small fixed thrombi in the left atrial appendage. It was cancelled in two patients with large thrombi in the left atrial appendage. Cardioversion was performed without embolic complications in 14 patients without left atrial thrombi. CONCLUSIONS--Transoesophageal echocardiography detects potential sources of embolism better than transthoracic echocardiography in selected patients at risk of cardiogenic embolism or after it.

Images

A 12-year-old girl with a high fever underwent echocardiography and was found to have a myxoma that arose from the atrial side of the anterior mitral valve leaflet. The tumor was successfully excised. Histologic examination of the tumor showed myxoma cells and an organized thrombus with bacterial colonization. The patient was discharged from the hospital on antibiotic treatment. After remaining asymptomatic for 3 weeks, she was readmitted with acute abdomen. Ultrasonography and magnetic resonance angiography detected intra-abdominal hemorrhaging and a saccular aneurysm of the abdominal aorta. The patient underwent successful emergency surgery.

To our knowledge, no other report has been published concerning an abdominal aortic aneurysm secondary to bacterial infection of a cardiac myxoma. Although complications this severe are rarely observed in patients who have endocarditis, early recognition and treatment can be life-saving.

A 53 year old man with a history of rheumatic mitral stenosis was admitted to hospital because of recurrent fainting spells. Auscultation showed a variable diastolic rumbling murmur. Simultaneous echo- and phonocardiograms demonstrated a floating left atrial thrombus; when this passed into the left ventricular inflow tract and obstructed the mitral valve orifice the diastolic murmur disappeared.

Images

In two patients with atypical myxomas of the left atrium, two-dimensional echocardiography furnished valuable diagnostic information. In one patient, who had previously developed an embolism at the right brachial artery, M-mode echocardiography revealed an abnormal band of echoes within the left atrium. Two-dimensional echocardiography showed a globular cluster of echoes that remained within the left atrial cavity throughout the cardiac cycle; left ventricular angiography confirmed the ultrasonic findings of an intraatrial mass. At surgery, a calcified, nonprolapsing myxoma was excised from the interatrial septum. The second patient had clinical as well as M-mode echographic features of mitral stenosis. Cardiac catheterization showed a significant gradient across the mitral valve, but the left ventriculogram was normal except for an unusual pattern of mitral regurgitation. Subsequent two-dimensional echocardiography revealed a mass of echoes that prolapsed through the mitral valve during diastole. At surgery, a left atrial myxoma was found attached to the posterior mitral annulus. Our experience indicates that two-dimensional ultrasound is superior to conventional echocardiography for detecting unusual cardiac masses.

Images

A disc valve of new design was used successfully for the replacement of the mitral valve in patients with rheumatic mitral valve disease. This valve would appear to have the following advantages over the mitral ball valve prosthesis:

• Lower left atrial pressure after replacement.

• Elimination of the hazard of left ventricular outflow tract obstruction with mitral valve replacement.

• Decreased incidence of thromboembolization.

• Abolition of possibility of ventricular septal irritation.

Despite the better outlook for this valve compared with the ball valve for mitral valve substitution, the mitral valve should always be repaired whenever feasible. Repair is possible in the majority of patients.

Images

We reports a case of a newly formed thrombus in the left atrial appendage during cardiopulmonary bypass detected by transesophageal echocardiography in a patient with chronic atrial fibrillation and mitral stenosis. This case alerts the anesthesiologists of possible thrombus formation despite full heparinization during cardiac surgery and the importance of a comprehensive echocardiography examination.

The aortic and mitral valves were replaced in 50 patients at the University of Alberta Hospital using the Starr-Edwards ball-valve prosthesis. The basis of the selection of 20 patients for isolated aortic valve replacement and 27 for mitral valve replacement using this type of prosthesis is presented, and the techniques of insertion of the aortic and mitral valve are described in detail. Of the 27 patients in whom the mitral valve was replaced by the Starr-Edwards prosthesis six died within 30 days of surgery and two after discharge from hospital at two and a half and four months, respectively. Left atrial thrombosis was the cause of death in four of these patients. In 20 patients in whom the aortic valve was replaced, four died in hospital and two died more than 30 days after returning home. Three of these six patients died from bleeding—the result of the use of anticoagulants. The difficulty in assessing whether or not anticoagulants are needed following replacement by a Starr-Edwards prosthesis is considered. It is felt, in our present state of knowledge, that anticoagulants should be used following mitral valve replacement but are probably not essential following replacement of the aortic valve. Two patients survived replacement of both aortic and mitral valves and have been followed up 18 months and seven months, respectively.

Images

OBJECTIVE--Systemic emboli related to atrial thrombi are a well known complication of percutaneous balloon dilatation of the mitral valve. The presence of left atrial thrombi therefore, is believed to be a contraindication to balloon dilatation. The purpose of this study was to determine the frequency of left atrial thrombi in patients referred for balloon dilatation of the mitral valve, the added benefit of pre-procedural transoesophageal echocardiography, and to identify factors that predicted left atrial thrombi. DESIGN--Prospective study over a 14 month period of 20 consecutive patients by cross sectional transthoracic echocardiography 24-48 hours before balloon dilatation of the mitral valve and by transoesophageal echocardiography immediately before the procedure. RESULTS--One patient had a left atrial thrombus detected by transthoracic study. Two patients (10%) had left atrial thrombi identified by transoesophageal echocardiography. In both valve dilatation was not attempted and the thrombi were confirmed at surgery. The remaining 18 patients all underwent successful balloon dilatation of the mitral valve without clinical evidence of an embolic event. No association was found between patient age, mitral valve area, transmitral gradient, left atrial size, presence of atrial fibrillation, severity of mitral regurgitation, cardiac output, or the presence of left atrial swirling and an increased prevalence of atrial thrombi. CONCLUSION--Left atrial thrombi are often seen despite long term systemic anticoagulation in patients referred for balloon dilatation of the mitral valve. The frequency of unsuspected left atrial thrombi detected by transoesophageal echocardiography was similar to the reported frequency of embolic events after balloon dilatation of the mitral valve. Transoesophageal echocardiography for the identification of left atrial thrombi is strongly recommended in all patients before balloon dilatation of the mitral valve including those treated with systemic anticoagulation and those who have had a normal transthoracic echocardiographic study.

Images