Isolated systolic hypertension (ISH) affects up to two thirds of all individuals with hypertension between the ages of 65 and 89 years,1 and its prevalence, as estimated by the Systolic Hypertension in the Elderly Program (SHEP) Pilot Study, ranges from 6% of individuals aged 60 through 69 years to 18% of those aged 80 years or older.2 This extremely common disease is an independent risk factor for the development of cerebrovascular and cardiovascular morbidity and mortality, and, in the Framingham Study, it was the single greatest risk factor other than age for the development of cardiovascular disease in the elderly population.3
Isolated systolic hypertension is believed to result from the pathophysiology of aging, which includes decreased connective tissue elasticity and atherosclerosis, resulting in increased peripheral vascular resistance,4 and diminished β2 receptor sensitivity, leading to decreased smooth muscle relaxation.5 Because of the presumed irreversible "stiffening"