Heart failure with preserved ejection fraction as a syndrome of reduced effective stroke volume

Heart failure with preserved ejection fraction (HFpEF) is traditionally characterized as a disorder of diastolic dysfunction. However, this framework does not fully explain the dissociation between preserved left ventricular ejection fraction (LVEF) and impaired functional capacity. HFpEF may be conceptualized as a syndrome of reduced effective stroke volume despite preserved LVEF. Structural remodeling, increased myocardial stiffness, and impaired diastolic suction contribute to limited ventricular filling, whereas preserved circumferential and radial mechanics may help maintain LVEF in some patients. This can result in a mismatch between forward flow and filling pressures, which may contribute to limited cardiac output reserve and, in a subset of patients, neurohormonal activation and congestion. This perspective is supported by existing physiological and clinical observations. HFpEF may present as a phenotype characterized by impaired systemic perfusion and elevated filling pressures in many patients, although significant heterogeneity exists.NEW & NOTEWORTHY This article proposes an integrative physiological framework in which heart failure with preserved ejection fraction (HFpEF) is conceptualized as a syndrome of reduced effective stroke volume despite preserved left ventricular ejection fraction. It highlights the dissociation between preserved ejection fraction and impaired forward flow, integrating ventricular filling abnormalities, myocardial deformation, diastolic suction impairment, and systemic hemodynamic consequences into a unified model. This perspective may improve understanding and management of HFpEF.