It is now well established that among patients with the clinical syndrome of heart failure (HF), approximately half have preserved systolic function, known most commonly as heart failure with preserved ejection fraction (HFpEF). Although originally considered to be predominantly a syndrome that pathophysiologically involves abnormalities in diastolic function (relaxation and/or stiffness), ongoing investigation suggests that, although diastolic abnormalities may be present in many patients, other aspects of pathophysiology likely also contribute to symptoms.