73-year-old female who developed new-onset atrial fibrillation (AF) with rapid ventricular response (RVR) further complicated by an unresolving left atrial appendage (LAA) thrombus and tachycardia-induced cardiomyopathy leading to Heart Failure with reduced Ejection Fraction (HFrEF). This report discusses the management strategies employed and the patient’s clinical progression over 11 months. We highlight the role, limitations, and possible alternatives of Direct oral anticoagulants (DOACs) in patients with LAA thrombus and the absence of clear consensus on what constitutes treatment failure with DOACs in such patients.