Unforeseen and Immediate: A Case of a Post-Watchman Device-Related Thrombus.

Atrial fibrillation (AFib) is recognized as a risk factor linked to arterial thromboembolism stemming from blood clot formation in the left atrium, associated with increased morbidity and mortality. Most of these thrombi originate in the left atrial appendage (LAA). Oral anticoagulation (OAC) therapy can help mitigate this risk. LAA occlusion (LAAO) has emerged as an option for patients who cannot safely tolerate long-term OAC. Watchman is one of the commonly used devices with a favorable safety profile demonstrated in numerous studies. One of the most concerning complications of LAAO is device-related thrombus (DRT), which may form on the atrial side of the device and potentially lead to embolization. We present a rare case of immediate DRT formation following the deployment of a Watchman device in a 78-year-old male with persistent AFib. Despite appropriate periprocedural management, a thrombus was observed immediately post implantation. This case emphasizes the need for vigilant surveillance, prompt diagnosis, and therapeutic intervention to manage such complications. The patient was successfully managed with a heparin drip, leading to thrombus resolution. This report underscores the complexities of managing DRT and the importance of ongoing research to optimize outcomes for patients undergoing LAAO.