Left Ventricular Mass: Intraoperative Transesophageal Echocardiography for Evaluation and Management

A 29-yr-old obese man with recent embolic stroke was brought to the operating room for resection of presumed intracardiac neoplasm suggested by preoperative imaging, including transthoracic echocardiography and cardiac magnetic resonance imaging. A significant history of cocaine use was revealed before surgery. The intraoperative transesophageal echocardiography (TEE) examination revealed mildly decreased left ventricular (LV) function (ejection fraction 45%) and confirmed a 25 × 15 mm mobile, pedunculated mass in the LV attached near the apex. A combination of mid-esophageal and transgastric views were used to image the mass, which was homogenous, noncalcified and noncavitated with higher echogenicity relative to myocardial tissue (Figs. 1 and 2). Regional wall motion abnormalities that were not described on initial studies were observed in the apex near the point of attachment of the mass. The apical anterior region was dyskinetic at the site of attachment with hypokinesis of the apical septal, lateral, and inferior segments (Video loop 1; please see video clip available at www.anesthesia-analgesia.org).Figure 1.: In the mid-esophageal two-chamber view, the mass can be seen in the left ventricular apex. LA = left atrium; LV = left ventricle; Mass indicated by arrow.Figure 2.: The transgastric long axis view of the left ventricle (LV) demonstrates the mass (indicated by arrow).The preoperative diagnosis of neoplasm was reconsidered in light of the regional wall motion abnormalities and the patient's substance abuse history. A presumptive diagnosis of postmyocardial infarct (MI) associated thrombus was made, although the presence and extent of coronary artery disease had not yet been evaluated with coronary angiography. If significant coronary artery disease was present and coronary artery bypass grafting was indicated, a revascularization procedure could be performed at the time of thrombectomy. For this reason, the procedure was postponed and coronary angiography was performed the following day. This study demonstrated nonobstructive disease with luminal irregularities in the left anterior descending artery, consistent with the wall motion abnormalities observed by TEE. Although coronary revascularization was not indicated, thrombectomy was performed due to a high level of concern regarding additional embolic events. The procedure and postoperative course were uneventful; surgical pathology of the specimen confirmed the diagnosis of infarcted myocardium with associated thrombus. Echocardiography (transthoracic and TEE) remains the imaging modality of choice in the initial assessment of cardiac sources of emboli. In formulating the differential diagnosis of an intracardiac mass, the examiner must evaluate the size, shape, mobility, location, and myocardial attachment or infiltration in addition to considering the overall clinical scenario. Although pathologic intracardiac masses can be due to infectious processes or malignancy, thrombus is a common intraventricular mass. LV thrombi are usually located in the apex in association with an infarcted region. LV tumors tend to be intramural rather than pedunculated, and may alter the echogenic properties and regional contractile function of the tissue. Although LV thrombus was historically a frequent complication of MI, occurring in 20%–60% of patients, the incidence has substantially decreased to approximately 4.3% since the advent of thrombolytic therapy and percutaneous interventions.1 Most thrombi develop within the first 14 days after an MI and can lead to systemic embolization in about 10% of the patients.1 LV thrombus is typically managed conservatively with anticoagulation, whereas surgical thrombectomy is reserved for patients at high risk for embolization due to prior embolic events, mobile and/or protrusive thrombus, or failed anticoagulation therapy.2,3 In a patient presenting for emergent coronary artery bypass grafting, detection of a previously unknown LV thrombus will greatly impact the intraoperative management. Resection of the thrombus may be considered, and the echocardiographer must monitor the thrombus during the procedure, particularly at times of cardiac manipulation and before release of aortic cross-clamp. Manipulation or instrumentation of the LV, including placement of a LV vent, should be limited and avoided when possible. During a planned surgical resection of an intracardiac mass, intraoperative TEE is used to confirm the presence of the reported mass in the expected location and to excluded additional cardiac masses or disease processes. TEE can also guide instrumentation of the heart if the lesion is located near the cannulation sites. After the procedure, TEE can confirm complete resection of the mass. A change in surgical plan as a result of new information provided by intraoperative TEE was reported in 16% of the patients undergoing resection of intracardiac masses in one study.4 In our patient, the intraoperative TEE examination established the correct diagnosis and altered management of the case. Medical management was considered as an alternative to surgery, although LV thrombectomy was ultimately performed. This case strongly demonstrates the need for a thorough perioperative TEE examination in patients presenting with intracardiac masses.