Left Atrial Thrombus Mimicking Myxoma Secondary to Rebound Hypercoagulable State

Novel oral anticoagulants (NOACs) have made the use of anticoagulation in patients with atrial fibrillation (AFib) much more convenient and predictable. It is a very common practice to hold anticoagulation either in anticipation of surgical procedures (to prevent excessive bleeding) or in case of acute bleeding episodes. This abrupt withdrawal of anticoagulation tilts the balance in favor of pro-thrombotic state in the body. We present a case of a 60-year-old man with past medical history of AFib who abruptly discontinued his apixaban (Eliquis). This patient presented to emergency room with the complaint of weakness and numbness of left arm and left half of the face. Stroke code was activated, and patient received tissue plasminogen activator (t-PA). This resulted in significant improvement of symptoms within hours of receiving treatment. Later during the same day, patient developed numbness and tingling of fingers of left hand. On physical exam, left hand was cold to touch and radial pulse was absent. Arterial duplex revealed occluded ulnar and radial arteries. Vascular surgery performed embolectomy to establish blood flow in the radial and ulnar arteries. Transthoracic echocardiogram revealed large left atrial mass attached to the atrial septum. Most likely t-PA infusion in the setting of atrial mass led to distal showering of emboli resulting in stenosis of radial and ulnar arteries. The left atrial mass was most likely thrombus as patient had cardiac imaging including transthoracic echocardiogram and computed tomography of heart prior to these events which did not reveal any mass in left atrium. In short, as clinicians we should be aware of the hypercoagulability associated with withdrawal of anticoagulation. In addition, we should be wary of the challenges associated with differentiating cardiac masses of different etiology. J Med Cases. 2021;12(6):243-247 doi: https://doi.org/10.14740/jmc3656