A 56-year-old man experienced episodes of severe substernal chest pain every time he performs a task that requires moderate exercise. The episodes have become more frequent and severe over the past year, but they can be relieved by sublingual nitroglycerin. On physical examination, he is afebrile, his pulse is 78/min and regular, and there are no murmurs or gallops. Laboratory studies show creatinine, 1.1 mg/dL; glucose, 130 mg/dL; and total serum cholesterol, 223 mg/ dL. Which of the following cardiac lesions is most likely to be present in this man?

Angina pectoris typically occurs when coronary artery narrowing exceeds 75%. His risk factors include hyperglycemia (diabetes mellitus) and hypercholesterolemia. Calcific aortic stenosis leads to left-sided congestive heart failure (CHF), and the extra workload of the left ventricle may cause angina pectoris. Calcific aortic stenosis (in the absence of a congenital bicuspid aortic valve) is rarely symptomatic at 50 years of age, however. Cardiomyopathies result in heart failure, but without chest pain. Patients with rheumatic heart disease are affected by slowly worsening CHF. Pericarditis can produce chest pain, although not in relation to exercise, and it is not relieved by nitroglycerin. Viral myocarditis may last for weeks, but not for 1 year, and pain may be present at rest.