About 50% of patients in the older age range who have heart failure have normal systolic function. There have been several major barriers to understanding the pathophysiology and therapy of this important disorder in the elderly. The diagnosis of diastolic heart failure is largely one of exclusion. The pathophysiology of this disorder is incompletely understood, but it appears to share pivotal features with systolic heart failure, including reduced exercise stroke volume and cardiac output, increased filling pressure, and neuroendocrine activation. Patients with diastolic heart failure can have severe exercise intolerance, reduced quality of life, and significant morbidity and mortality. There are no large randomized trials with which to definitively guide therapy. Currently, therapy is empiric. Control of systolic blood pressure and left ventricular hypertrophy appear to be important...