Heart failure occurs when the heart cannot pump enough blood to meet the body’s needs, or only does so at the cost of high pressure inside the heart. Heart failure with preserved left ventricular systolic function (HFpEF) means a patient experiences typical heart failure symptoms, such as shortness of breath and fatigue, even though the heart’s main pumping action remains strong. The problem lies not in the heart’s ability to contract, but in its inability to relax and fill properly. HFpEF is increasingly common, now accounting for approximately half of all heart failure cases.
Understanding the Function of the Left Ventricle
The left ventricle (LV) is the heart’s primary muscular chamber responsible for propelling oxygenated blood out to the entire body’s circulatory system. The performance of this pumping action is quantified by a measurement known as the Ejection Fraction (EF). The Ejection Fraction is the percentage of blood volume that the left ventricle pushes out with each single heartbeat. In a healthy heart, the left ventricular ejection fraction typically falls within the range of 50% to 70%. Heart failure with preserved function is specifically defined when a patient has symptoms of heart failure, yet their ejection fraction remains at 50% or higher.
Distinguishing Preserved Function from Reduced Function
The two major types of heart failure are distinguished by how the left ventricle operates. Heart failure with preserved ejection fraction (HFpEF) is fundamentally a problem of impaired filling, or diastolic dysfunction. During the resting phase of the cardiac cycle, the LV muscle becomes abnormally stiff and fails to relax fully, preventing it from accepting a sufficient volume of blood from the atrium. This stiffness limits the amount of blood entering the ventricle before contraction.
Because the LV starts with a smaller volume, the total amount of blood pumped out to the body is inadequate, despite the percentage of blood ejected (the EF) remaining preserved. In contrast, heart failure with reduced ejection fraction (HFrEF) is characterized by systolic dysfunction, which is a pumping problem. In HFrEF, the heart muscle is weakened and floppy, meaning it cannot contract forcefully enough to eject an appropriate percentage of blood, usually resulting in an EF of 40% or lower. The stiffening in HFpEF causes pressure to build up quickly within the heart and subsequently back into the lungs, leading to congestion symptoms.
Primary Causes and Associated Conditions
The underlying cause of left ventricular stiffness in HFpEF is often the presence of multiple chronic health conditions that promote inflammation and structural changes in the heart muscle. Long-standing, uncontrolled hypertension, or high blood pressure, is the most common cause for developing preserved-function heart failure. Sustained high pressure forces the heart to work harder, leading to the thickening and stiffening of the LV muscle, a process called left ventricular hypertrophy and remodeling.
Metabolic disorders also play a significant role, particularly type 2 diabetes and obesity. These conditions create a state of chronic, low-grade inflammation throughout the body, which directly damages the heart muscle and surrounding small blood vessels. This inflammation triggers the excessive buildup of fibrous tissue, or fibrosis, within the heart muscle. This fibrotic tissue further contributes to the ventricle’s rigidity and its inability to relax effectively during the filling phase. Chronic kidney disease is another associated condition that contributes to the pathology of HFpEF.
Management Approaches
The strategy for managing HFpEF centers on controlling the associated chronic conditions that caused the heart to stiffen. Since high blood pressure and diabetes are major drivers, treatment focuses on managing blood pressure and blood sugar levels. This approach aims to reduce the systemic inflammation and the strain that is continually remodeling the heart muscle.
For the immediate relief of symptoms, diuretics are a cornerstone of therapy, used to manage the fluid buildup that results from the heart’s poor filling. These medications help the body excrete excess water and salt, which alleviates congestion and shortness of breath. Lifestyle modifications, including adopting a heart-healthy diet and engaging in regular physical activity, are important to improve overall cardiovascular function and reduce weight. Recent advances have also shown that certain medication classes, such as SGLT2 inhibitors, can significantly reduce the risk of hospitalization and improve outcomes.