A 53-yr-old woman with a left ventricular assist device (LVAD), placed 4 mo before admission for idiopathic dilated cardiomyopathy, was awaiting heart transplantation. She was found unresponsive at home with low cardiac output from her LVAD. No signs of fractures or thoracic bruising were present and she did not require chest compressions for resuscitation. During transport to the hospital, she was tracheally intubated, started on inotropic drugs, and transferred directly to the operating room on arrival to the hospital for surgical evaluation. Transesophageal echocardiography (TEE) was performed in the operating room to evaluate the patient’s critical condition. TEE demonstrated a fluid collection adjacent to the right ventricle (RV) in the midesophageal four-chamber view at 0° and midesophageal long axis view at 87° rotation (Fig. 1, video clip 1; please see video clip available at www.anesthesia-analgesia.org). The LVAD inflow cannula in the left ventricle did not show any signs of obstruction or malpositioning, the LVAD outflow cannula in the aorta was not visible on TEE, although TEE is an ideal technique for evaluating LVAD placement and function.1 A drain was placed percutaneously via a subxiphoid approach under TEE guidance by visualizing the position of the paracentesis cannula in the fluid cavity. The patient remained hemodynamically unstable with continuing drainage of a large amount of blood. Further inspection on TEE with color flow Doppler revealed a communication between the fluid cavity and the RV (Fig. 2, top). Pulsed wave Doppler identified flow from the RV into the RV dissection cavity (Fig. 2, bottom). Cardiopulmonary bypass was initiated via cannulation of the femoral vessels. During surgical exploration, the RV was found to be dissected in a large portion, producing an intramural pocket. Therefore, the surgical finding confirmed the primary diagnosis made on TEE. The RV was considered irreparable by the surgeon because of the large ventricular dissection in conjunction with extremely friable myocardial tissue. The patient’s overall detrimental condition before surgery in conjunction with an irreparable RV resulted in the decision to discontinue cardiopulmonary bypass and declare the patient dead. Postmortem autopsy confirmed the surgical finding of an intramural RV dissection.Figure 1.: Midesophageal four-chamber view at 0° rotation demonstrating a fluid filled cavity (*) adjacent to the right ventricle (RV) (top). The same fluid collection (*) is demonstrated in the midesophageal long-axis view at 87° rotation (bottom). LA = left atrium.Figure 2.: Color Doppler demonstrating flow from the RV cavity to the dissection cavity (*) (top). Pulsed wave Doppler placed at the communication of the RV cavity with the dissection demonstrates flow between the two cavities (bottom). LA = left atrium.RV dissection is infrequent, and can result from myocardial infarction, coronary artery balloon angioplasty, thrombolytic therapy, cardiac operation, or chest trauma.2,3 It may also occur spontaneously with unknown etiology.4 The differential diagnosis for RV fluid collection includes pericardial hematoma, RV rupture and pseudoaneurysm of the RV. An echocardiographic feature of RV dissection is an intramyocardial hypoechoic cavity that is contained between an intact endocardium and epicardium communicating with the ventricular cavity. The shape of this neocavity reflects the tendency to dissect along the spiral myocardial fibers and the dissection hematoma is entirely within the myocardium. TEE is able to diagnose a RV dissection by identifying an entry and/or exit site of the dissection cavity. However, the diagnosis is often only possible on surgical exploration. Preoperatively, the communication between the RV and the dissection cavity might be difficult to identify with transthoracic echocardiography, computed tomography, or magnetic resonance imaging, and can be misdiagnosed for a subepicardial hematoma or pseudoaneurysm. A pseudoaneurysm occurs when the rupture is contained by an overlying adherent pericardium with a high propensity to rupture. In contrast to a RV dissection, TEE demonstrates myocardial rupture with disruption of the endocardium and/or epicardium in patients with pseudoaneurysm. Pseudoaneurysms are often associated with thrombi and pericardial effusions, particularly in the inferior and inferoposterior segments of the left ventricle due to the solitary blood supply in this region of the heart. In addition, subepicardial hematoma might result from an unrecognized coronary artery perforation during percutaneous coronary intervention. A subepicardial hematoma is a pseudoaneurysm with the containing wall composed of intact epicardium, sometimes with a thin myocardial layer; the hematoma is contained entirely within the myocardium.5 The blood within the hematoma originates either from the ventricular cavity or is of intramural origin. Subepicardial hematoma demonstrates as an echo-free space between the ventricular muscle and the pericardium.6 Intramural RV dissection or RV hematoma often results in dismal patient outcome due to tamponade of the ventricular cavity and the associated tamponade physiology.7 The presented case demonstrates the role of echocardiography in the diagnosis of pericardial and intramural pathology in hemodynamically instable patients, since demonstration of a communication of the ventricular cavity with a dissection is often not possible on TEE.
A summary is not available for this content so a preview has been provided. Please use the Get access link above for information on how to access this content.