P1309 A jellyfish in the sea

Background The unexpected presence of a left ventricular (LV) mass is always a cause of concern for physicians. This is especially so in the presence of a cerebrovascular accident and a recent cardiac event, where the hunt for a cardioembolic source begins. We describe a case of an unusual presentation of a LV thrombus masquerading as a cystic mass, where diagnosis was confirmed with multimodality imaging tools. Purpose A 58 year old Thai male first presented to the emergency department with left brachio-facial syndrome secondary to a right pre-central gyrus stroke. He had chest pain 2 days prior, and was pain free on admission. An electrocardiogram done showed an evolved anterior myocardial infarction. Methods and Results A transthoracic echocardiogram performed on the 4th day of admission revealed a mildly impaired left ventricular systolic function with an ejection fraction of 45%, and wall motion abnormalities in the left anterior descending artery territory. There was an apical gelatinous-like, cystic and mobile mass with soft flexible walls, measuring 2.4 X 2.1cm. Differentials at this point included cystic thrombus, hydatid cyst, capillary haemangioma and intracardiac tumour. A cardiac MRI was performed which showed an irregular apical mass with features suggestive of fresh thrombus. The mass demonstrates hyperintensity T1-w FSE sequences (with and without fat sat), increased hyperintensity in T2-w triple IR FSE, with no increased uptake in first pass perfusion, T1-w post contrast, or early and late gadolinium enhancement images. A repeat transthoracic echocardiogram done 11 days after anticoagulation showed a 50% reduction in the size of the mass. See images below for more information. Conclusion In the era of early primary percutaneous coronary intervention and anticoagulation following an acute myocardial infarction (AMI), LV thrombus is an uncommon complication. It can occur within 2 weeks after an AMI, where increased blood stasis from dyskinesia or akinesia of associated wall segments, and a hypercoagulable state increases the risk of thrombus formation. A literature search has shown that presentation of the thrombus as a cystic mass is rare as well. As such, early diagnosis allowing for early treatment, especially when systemic embolism of thrombus is suspected, is important. Other causes of cystic LV thrombus do need to be considered in the relevant clinical context. These include infectious causes such as hydatid cyst, capillary hemangioma or intracardiac tumour, which are less likely given the history and investigation results. In this case, a trial of therapy with anticoagulation reduced the size of the cystic mass, and along with imaging findings, confirmed the diagnosis of a cystic LV thrombus. Abstract P1309 Figure. TTE and MRI heart