An 82-year-old woman with a history of heart failure from coronary heart discase visits your office because she is having increasing symptoms. Her last visit was 4 months ago classified her as having NYHA class ll func onal status. Her ejection fraction is 35% She states that over the past 3 weeks she has gained 5kg, new onset of dyspnea while walking from her kitchen to her living room, which she used to do without difficulty. She has recently begun sleeping in a chair propped up because of difficulty breathing while lying flat. She takes valsartan 80 mg/d, sustamed-release metoprolol 50 mg/d, simvastatin 40 mg/d, and aspirin 81 mg/d, all of which she is tolera ng well. Her physical examination reveals an 8 Kg weight gain from her previously documented weight, a blood pressure of 118/74 mmHg, a heart rate of 63 bpm and regular, a respiratory rate 18 breaths/min, and a room air oxygen saturation of 96% at rest that decreases to 91% with hallway ambula on. She has VD. You hear basilar crackles in her lungs and her heart examination reveals a normal rhythm without murmurs or extra sounds. She has 1+ pi ng edema in her extremities. The next step in this patient's management is to?