Q. A 52-year-old male was admitted two days ago following an episode of hemoptysis. Recently, the patient has experienced shortness of breath with exertion, fatigue, and unexplained weight gain. He has a history of smoking 1 pack of cigarettes per day, excessive alcohol and methamphetamine use, and also has hypertension, dislipidemia, and diabetes, which are all poorly controlled. An EKG on admission demonstrated no signs of ischemia, though prolongation of the QRS complex and the QTc were noted. The patient’s chest x-ray (see image) revealed a bottle-shaped cardiac silhouette, Kerley B lines, and reticular opacifications, with no effusions noted. On physical examination today, his blood pressure is 165/100 mm Hg, heart rate 85/min, respiratory rate 26/min, and oxygen saturation is 95 percent on room air. Muscle strength is equal bilaterally and no focal neurologic deficits are appreciated. Bilateral venous jugular distention is observed 3 cm above the sternal angle. Auscultation of his chest reveals crackles and expiratory wheezes in both lung fields, with no focal consolidations. Cardiac assessment demonstrates an increased P2 component of the second heart sound, and an S3 gallop. Ascites, abdominal distention, and bilateral lower extremity dependent edema is also present. Based on the information you have at this point, which of the following is the LEAST likely cause of this patient’s declining pulmonary function?