A 49-year-old man with a long-standing history of chronic renal failure as a consequence of diabetic nephropathy is brought to the emergency room for nausea, lethargy, and confusion. Examination : His physical examination is significant for an elevated jugular venous pressure, clear lung fields, and harsh systolic and diastolic sounds heard over the precordium.

Serum chemistries reveal K 5.1 mEq/L, CO2 17 mEq/L, BUN 145 mg/dL, and creatinine 9.8 mg/dL. Source: Case Files Internal Medicine