Stewart Hanna is a 58-year-old partner in a real estate firm. Over the years, the pressures of the job have taken their toll. Mr. Hanna has smoked two packs of filtered cigarettes a day for 40 years. He tries to watch his diet, but required business lunches and cocktail hours have driven his weight up to 210 lb. (He is 5 feet, 9 inches tall.) He recently separated from his wife of 35 years and is dating a much younger woman. Suddenly realizing how out of shape he had become, he made an appointment for a physical examination. In his physicians office, Mr. Hannas blood pressure was 180/125 (normal, 120/80). The physician heard a continuous abdominal bruit (sound). Because of Mr. Hannas elevated blood pressure and the bruit, the physician drew a venous blood sample to determine plasma renin levels. After receiving the results, the physician ordered an additional test called a differential renal vein renin. Mr. Hannas plasma renin activity was 10 ng/mL per hour (normal, 0.9 to 3.3 ng/mL per hour). His differential renal vein renin (left to right) was 1.6 (normal is 1.0). The test results were consistent with left renal artery stenosis. Mr. Hanna was scheduled for a renal arteriogram, which showed 80% occlusion of the left renal artery as a result of severe atherosclerotic disease. A balloon angioplasty was performed immediately to clear the occlusion. Mr. Hannas blood pressure was expected to return to normal after the procedure. He was ordered to stop smoking, follow a low-fat diet, exercise regularly, and undergo periodic physical examinations.