A 73-year-old man has developed worsening congestive heart failure over the past year. On physical examination, hehas pitting edema to the thighs. There is dullness to percussion at the lung bases. He develops pneumonia and dies. At autopsy, there is marked right ventricular and right atrial dilation and hypertrophy. The aorta shows minimal atherosclerosis, and the pulmonary trunk shows moderate atherosclerosis. Which of the following conditions is most likely to have produced these findings? (A) Saddle pulmonary thromboembolism (B) Ventricular septal defect (C) Chronic obstructive pulmonary disease (D) Rheumatic heart disease (E) Hypertrophic cardiomyopathy