Anterior Loculated Pericardial Effusion Misinterpreted as Right Heart Dilation Suggesting Pulmonary Embolism

We report a case of anterior loculated pericardial effusion misinterpreted on point-of-care ultrasound as a dilated right ventricle, and suggesting diagnosis of pulmonary embolism (PE), in a patient with renal failure. The compressed right ventricle from tamponade physiology appeared to be a thickened intraventricular septum. Heparin was given empirically for presumed PE. Later the same day, computed tomography of the chest showed the effusion, as did formal echocardiogram. The patient had drainage of 630 milliliters of fluid and recovered from tamponade. Loculated effusions comprise 15% of all pericardial effusions, and misdiagnosis of PE with heparin therapy could be fatal.