64-year-old man with dyspnea and weight gain.

nd ine, , A 64-year-old man presented to our institution for evaluation of worsening dyspnea on exertion and weight gain. He had recently been hospitalized for syncope related to paroxysmal atrial fibrillation with a rapid ventricular response, which was managed with rate control followed by atrioventricular node ablation. Since dismissal, he had experienced decompensation with progressive lower extremity edema, dyspnea on exertion, and orthopnea. During 1 week, he gained 6.3 kg despite increasing his diuretic dosage. The patient’s medical history was notable for ischemic cardiomyopathy with biventricular heart failure status after implantable cardioverter-defibrillator placement 6 years previously for primary prevention, upgraded to cardiac resynchronization therapy-defibrillator (CRT) 6 months before the current admission; coronary artery disease status after 4-vessel coronary artery bypass surgery 20 years previously; paroxysmal atrial fibrillation managed with long-term anticoagulation; type 1 diabetes mellitus treated via an insulin pump; sleep apnea managed with continuous positive airway pressure; and living donor renal transplant 8 years previously managed with long-term immunosuppression without any episodes of rejection. His medications included carvedilol, losartan, digoxin, hydralazine, isosorbide mononitrate, pravastatin, torsemide, warfarin, aspirin/extended-release dipyridamole, mycophenolate mofetil, tacrolimus, and prednisone. He had never smoked, did not drink alcohol, and had no history of intravenous drug use. His family history was remarkable for coronary artery disease, heart failure, and renal failure in his mother and diabetes and coronary artery disease in his father. Physical examination revealed an overweight man with a body mass index of 27.1 kg/m, blood pressure of 109/69 mm Hg, heart rate of 60 beats/min, and temperature of 36.8 C. Cardiac examination showed an irregularly irregular rhythm with a grade