Review Question - QID 206193

A 72-year-old female presents to the emergency department following a syncopal episode while walking down several flights of stairs. The patient has not seen a doctor in several years and does not take any medications. Your work-up demonstrates that she has symptoms of angina and congestive heart failure. Temperature is 36.8 degrees Celsius, blood pressure is 160/80 mmHg, heart rate is 81/min, and respiratory rate is 20/min. Physical examination is notable for a 3/6 crescendo-decrescendo systolic murmur present at the right upper sternal border with radiation to the carotid arteries. Random blood glucose is 205 mg/dL. Which of the following portends the worst prognosis in this patient?