- Heart failure with preserved ejection fraction (HFpEF) occurs when the lower left chamber (left ventricle) is not able to fill properly with blood during the diastolic (filling) phase. The amount of blood pumped out to the body is less than normal. It is also called diastolic heart failure. - Nearly half of all patients with heart failure have a normal ejection fraction (EF). The prevalence of this syndrome, termed heart failure with preserved ejection fraction (HFpEF), continues to increase in the developed world, likely because of the increasing prevalence of common risk factors, including older age, female sex, hypertension, metabolic syndrome, renal dysfunction and obesity.