Incidental Finding of a Right Atrial Appendage Thrombus in a Patient With Dilated Cardiomyopathy and Diffuse B-cell Lymphoma.

Right atrial thrombus is a rare phenomenon linked with a high risk of mortality. We present a case of a 75-year-old male with dilated cardiomyopathy and B-cell lymphoma on chemotherapy via an implanted chemo port who presented with dyspnea secondary to new-onset atrial flutter. During the evaluation for new-onset atrial flutter, a thrombus in the right atrial appendage was incidentally found on transesophageal echocardiogram (TEE). This finding was confirmed with cardiac magnetic resonance imaging. A multidisciplinary heart team evaluation was performed, and the patient was deemed not a surgical candidate. The patient was discharged on apixaban for the right atrial thrombus treatment and later deferred to hospice care. This case highlights that there are no formal guidelines for managing right atrial thrombi (RAT), but treatment options include anticoagulation, thrombolytic therapy, and surgical thrombectomy or embolectomy with vacuum extraction. Additional research is needed to develop appropriate guidelines for management and prevent further systematic complications.