Heart failure is a medical condition where the heart muscle does not pump blood as effectively as it should to meet the body’s needs for oxygen and nutrients. This can occur if the heart becomes too weak to pump forcefully or too stiff to fill properly. When the heart’s pumping action is insufficient, blood can back up, leading to fluid accumulation in the lungs and other parts of the body. Heart failure is a lifelong condition, though its symptoms can be managed through treatment and lifestyle adjustments.
Understanding Preserved Ejection Fraction
Ejection fraction (EF) is a measurement indicating the percentage of blood leaving the heart’s main pumping chamber, the left ventricle, with each contraction. For a healthy heart, the left ventricular ejection fraction (LVEF) ranges between 50% and 70%. This means that with every beat, most of the blood within the ventricle is pumped to the body.
Heart failure with preserved ejection fraction (HFpEF) occurs when the heart’s pumping function, as measured by EF, appears normal, yet the heart cannot supply enough blood. The heart muscle becomes stiff and does not relax adequately between beats to fill with a sufficient volume of blood. Imagine a stiff sponge that can be squeezed forcefully but cannot soak up much water; similarly, the heart contracts well but holds less blood.
This contrasts with heart failure with reduced ejection fraction (HFrEF), where the issue is a weakened heart muscle that cannot contract forcefully enough to eject blood effectively. While both conditions lead to heart failure symptoms, the underlying mechanical problems differ. In HFpEF, the problem lies in the heart’s ability to relax and fill, even though its squeezing action remains preserved.
Causes and Associated Symptoms
Heart failure with preserved ejection fraction results from chronic medical conditions that gradually alter the heart’s structure and function. High blood pressure is a common cause, as it can lead to increased left ventricular muscle mass and stiffness over time. Other factors include type 2 diabetes, obesity, coronary artery disease, and the natural aging process.
These conditions can change the heart, making it less flexible and impairing its ability to fill properly with blood. Atrial fibrillation, chronic kidney disease, and obstructive sleep apnea are also associated with HFpEF. While not every case has a single cause, these chronic stressors collectively contribute to the heart muscle stiffening.
Symptoms of HFpEF arise because the stiffened heart cannot fill adequately, leading to reduced blood flow and fluid backing up. Patients experience shortness of breath, particularly with exertion or when lying flat. Fatigue and a reduced capacity for exercise are common, as the heart struggles to meet the body’s increased demands during activity.
Fluid retention can manifest as swelling, or edema, in the legs, ankles, and the abdomen. A persistent cough may also occur due to fluid accumulation in the lungs. These symptoms, while similar to other forms of heart failure, stem specifically from the heart’s impaired relaxation and filling ability in HFpEF.
The Diagnostic Process
Confirming a diagnosis of heart failure with preserved ejection fraction involves clinical assessment and specific medical tests. A healthcare professional begins by reviewing a patient’s medical history and performing a physical examination to identify signs of fluid overload or heart dysfunction.
The echocardiogram (echo) is a primary diagnostic tool. This non-invasive test uses sound waves to create moving images of the heart, allowing doctors to visualize its structure, measure ejection fraction, and assess how the left ventricle relaxes and fills. It provides insights into heart muscle stiffness and other functional abnormalities.
Blood tests are performed, focusing on natriuretic peptides like BNP or NT-proBNP. Elevated levels of these peptides can indicate heart strain and fluid overload. An electrocardiogram (ECG or EKG) can assess the heart’s electrical activity and detect any irregular rhythms or signs of heart muscle thickening.
In some cases, a cardiac stress test may be performed. This test helps evaluate how the heart functions under exertion, potentially unmasking diastolic dysfunction. Advanced imaging like cardiac MRI might also be used to rule out other conditions that can mimic HFpEF.
Current Treatment Strategies
Managing heart failure with preserved ejection fraction focuses on alleviating symptoms, improving quality of life, and preventing hospitalizations, rather than offering a cure. Treatment involves three main areas: managing underlying health conditions, implementing lifestyle modifications, and using specific medications.
Controlling existing medical conditions is crucial. This involves management of high blood pressure, aiming for targets below 130/80 mm Hg, and control of blood sugar levels for individuals with diabetes. Addressing obesity, coronary artery disease, and other associated conditions plays a role in reducing the burden on the heart.
Lifestyle modifications are recommended for patients with HFpEF. Adopting a low-sodium diet helps reduce fluid retention and ease the heart’s workload. Regular physical activity can improve functional capacity and overall well-being. Weight management is beneficial, as excess weight can exacerbate symptoms.
Medications are prescribed to manage symptoms and prevent disease progression. Diuretics are commonly used to reduce fluid buildup in the lungs and extremities, thereby easing shortness of breath and swelling. Newer classes of drugs, such as SGLT2 inhibitors, have shown promise in improving outcomes for HFpEF patients, including reducing hospitalizations for heart failure.
SGLT2 inhibitors have shown cardiovascular benefits in HFpEF regardless of diabetes status, becoming a recommended part of treatment. Other medications, including ARNIs, ARBs, and MRAs, may be considered to reduce hospital admissions.