Mobile pedunculated left ventricular masses in a man with recurrent emboli.

A 51-year-old man was found to have left ventricular masses by transthoracic echocardiography, one attached to the posterior wall of the left ventricle and another attached to the anterolateral wall of the left ventricle. He had several events of systemic embolization over the last few weeks. Surgical excision was recommended to avoid further embolization. The patient underwent successful resection of the left ventricular masses under cardiopulmonary bypass through the left atrial and transverse aortotomy approach. Histopathologic exam was diagnostic for organized thrombi.

INTRODUCTION

Intracardiac masses are mostly thought to be thrombi or tumors.[1] The left ventricular thrombus is usually located in the aneurismal or akinetic apical left ventricle.[2] We describe a case of left ventricular thrombi with several events of systemic embolization that were located in the areas that were not akinetic or hypokinetic.

CASE REPORT

A 51-year-old man presented to the Neurologic Department because of right-sided weakness and recurrent left-sided paresthesias and bilateral visual disturbance for two weeks. He had a history of hypertension, diabetes mellitus, hyperlipidemia and smoking. He also had a history of myocardial infarction three years earlier.

Computed tomography scan of the patient's brain demonstrated evidence of bioccipital ischemic infarct and multiple regions of lacunar infarction of basal ganglia and internal capsule. General hematological and biochemical tests were normal. To evaluate the source of emboli, Carotid Doppler measurements and transthoracic echocardiography was performed. Carotid Doppler measurements were normal. Transthoracic echocardiography showed mild left ventricular dilatation with moderate systolic dysfunction (ejection fraction 35-40%), akinesia of base of infeior segment andhypokinesia of lateral (base and mid) segment. There were two mobile masses in the left ventricle, one attached to the posterior wall of the left ventricle (2.5 × 1.8 cm) and another mass (2.8 × 2.2 cm) attached to the antrolateral wall of the left ventricle (mid part) which suggested cardiac tumor [Figure 1]. The patient was referred to our cardiology department for evaluation of cardiac masses. Transesophageal echocardiography was performed and confirmed TTE findings. Cardiac magnetic resonance imaging was not obtainable as a result of patient noncompliance. Due to our patient's regional wall motion abnormalities and history of myocardial infarction and diabetes, a coronary angiography was performed which showed severe three vessels disease. Our presumptive diagnosis was left ventricular myxoma. In view of these findings and the history of recurrent systemic embolism, the patient subsequently underwent open heart surgery for coronary artery bypass graft (CABG) and tumor resection. Trans-left atrial excision of the mass was performed through a median sternotomy with cardiopulmonary bypass. A reddish purple colored mass with an irregular surface (2.5 × 2 cm in diameter) was identified, that was attached to the posterior wall of the ventricle below the posterior mitral leaflet by a 2-3 mm tissue stalk about 1.5 cm under the mitral annulus. Another mass was not accessible trans-left atrium and mitral valve, thus a transverse aortotomy was performed. A reddish purple colored irregular surface mass (3 × 4 cm in diameter) that was attached to the antrolateral wall of the ventricle about 5 cm under the aortic annulus was excised. After resection of the masses CABG was performed. Postoperative recovery was uneventful. The histologic diagnosis revealed an organizing thrombus with no evidence of tumor cells [Figure 2].

Figure 1

Transthoracic echocardiogram showing the masses attached to the (a) posterior wall of the left ventricle, (b) anterolateral wall of the left ventricle

Figure 2

Microscopic finding of the thrombus in the left ventricle

The patient was discharged with slight improvement of neurological deficit. Transthoracic echocardiogram showed no evidence of residual mass and ejection fraction had improved to 45%.

DISCUSSION

Masses in the left ventricle (LV) are usually intracardiac tumors, thrombi or vegetations.[1] We made a presumptive diagnosis of LV myxoma based on echocardiographic and intraoperative appearance of pedunculated, mobile masses that were in the areas of the left ventricle that were not akinetic or hypokinetic (under the posterior mitral leaflet on the posterior wall and on the anterolateral wall). However, histology revealed the masses to be thrombi.

Thrombi generally involve the apex of the left ventricle, most often in the presence of akinesis or dyskinesis. LV thrombus formation is extremely rare in the absence of an akinetic or dyskinetic apex or diffuse LV dysfunction.[23] The vast majority of these thrombi are mural, flat, and immobile, and have a low risk of embolism. Mobile, pedunculated thrombi are rare in comparison with mural thrombi, however, they have a significantly higher risk of embolism.[4-6]

There are no established protocols for management of these cases. Although anticoagulant treatment may cause some left ventricular thrombi to resolve and the risk of systemic emboli may be reduced significantly, recurrent embolization during anticoagulant treatment has been reported. Moreover, the outcome of patients with recurrent emboli from mobile, pedunculated thrombi who are not treated surgically is generally very poor compared with that of the limited number who undergo surgery.[5] Left ventricular thrombectomy should be considered in patients in whom a very high-risk thrombus morphology is detected.[6] These thrombi are usually of a pedunculated globular nature connected to the endocardium by a very narrow stalk, moving freely in a "wavy" motion within the LV lumen, and constitute a risk for embolization of a magnitude approaching 60-80%.[7]

Therefore we strongly believe that patients with prior embolism must be offered immediate surgery, especially if the thrombus is large with an irregular surface, pedunculated, and multiple in number. Making an incision in the ventricular wall may cause further deterioration of the LV function, especially if the LV function is already poor. In addition, an incision in the ventricular wall may increase the risk of bleeding, and ventriculotomy may potentially induce ventricular arrhythmia and poor function.[89] The surgical approach to LV masses can be made through the left atrium, aorta, or left ventricle.[10] Our surgical approach to the LV mass was through the left atrium. The second mass was not accessible through the left atrium, thus a transverse aortotomy was performed.

In this case the presentation of LV masses was atypical for two reasons: Thrombi were in areas of the left ventricle that were not akinetic or hypokinetic, and the morphology of the thrombi was unusual.