Contribution of systolic and diastolic abnormalities to heart failure with a normal and a reduced ejection fraction.

Heart failure (HF) has traditionally been divided into HF with a reduced ejection fraction (EF; systolic HF) and HF with a normal EF (diastolic HF). Both groups have reductions in exercise tolerance, neurohumoral activation, and abnormal left ventricular (LV) filling dynamics and impaired relaxation. Although the normal EF indicates that pump performance is adequately compensated, some of the patients with HF and a normal EF have reduced longitudinal systolic velocity indicating cardiac muscular contractile dysfunction. Regardless of EF, the severity of HF and its prognosis and degree of exercise intolerance are closely related to the degree of diastolic filling abnormalities. Patients with HF and a reduced EF have ventricular dilatation and elongated myocytes, whereas patients with HF and a normal EF do not. Thus, patients with HF have diastolic abnormalities regardless of EF and many patients with HF and a normal EF have contractile abnormalities despite preserved systolic pump performance. Heart failure with a normal EF and a reduced EF differs in the systolic LV pump performance and the type of remodeling. The mechanism of the differing remodeling responses is not known, but aging, sex differences, and diabetes may contribute.