A 64 yo female with with history of atrial fibrillation, Chronic Obstructive Pulmonary Disease, hypertension, hyperlipidemia, repair of an atrial septum defect which was complicated by sternal wound infection and post-operative atrial fibrillation treated with amiodarone, was initially admitted through the Emergency Department with shortness of breath and back pain, and was noted to have atrial fibrillation with rapid ventricular response. A computed tomography angiography demonstrated diffuse left anterior descending artery and post-obstructive pneumonia concerning for malignancy. For her atrial fibrillation, she was started on diltiazem. For the pneumonia, she was treated with antibiotics. She was then transferred to the floor later that same night on metoprolol 50 mg tid. While on the floor, she had a bronchoscopy performed which showed external compression of her left mainstem bronchus, and she had a biopsy via fine-needle aspiration, which showed large cell carcinoma. She denies chest pain, shortness of breath and tachypnea. She does note some diaphoresis and occasional palpitations.