A 55-year-old man is diagnosed with heart failure 3 years ago. Today on physical examination, his BP is 138/82 mmHg and heart rate is 88/min. He doesn't have jugular venous distention or peripheral edema. The lungs are also clear. He is asymptomatic at this time. An electrocardiogram shows left ventricular hypertrophy without any evidence of previous myocardial infarction. An echocardiogram shows left ventricular hypertrophy with left ventricular ejection fraction of 42%. He is taking hydrochlorothiazide and lisinopril at this time.