Heart failure describes a condition where the heart struggles to pump enough blood for the body’s needs. This can happen if the heart muscle becomes too weak or too stiff. Among the various types of heart failure, heart failure with mildly reduced ejection fraction (HFmrEF) represents a distinct category. It occupies an intermediate position between heart failure where the pumping ability is significantly diminished and heart failure where it is largely preserved.
Understanding Heart Failure with Mildly Reduced Ejection Fraction
Ejection fraction (EF) is a measurement indicating the percentage of blood pumped out of the left ventricle, the heart’s main pumping chamber, with each beat. This figure helps healthcare providers assess the heart’s pumping efficiency. When classifying heart failure, an ejection fraction of 40% or less typically defines heart failure with reduced ejection fraction (HFrEF). Conversely, heart failure with preserved ejection fraction (HFpEF) is diagnosed when the ejection fraction is 50% or higher.
Heart failure with mildly reduced ejection fraction (HFmrEF) is characterized by an ejection fraction ranging from 41% to 49%. Medical guidelines define this intermediate range. The recognition of HFmrEF as a distinct category helps guide more tailored diagnostic and treatment approaches.
Recognizing the Symptoms
Individuals experiencing heart failure with mildly reduced ejection fraction often present with symptoms stemming from the heart’s decreased pumping capacity. Shortness of breath is a common complaint, particularly during physical activity or when lying flat. This occurs because the heart struggles to efficiently move blood forward, leading to fluid accumulation in the lungs. Fatigue and generalized weakness also frequently arise, as the body’s tissues and organs do not receive adequate oxygenated blood.
Fluid retention can manifest as swelling, or edema, in the legs and ankles. This happens when the heart’s reduced pumping causes blood to back up in the veins, forcing fluid into surrounding tissues. A persistent cough, which may worsen at night or when lying down, can also be a sign of fluid buildup in the lungs.
Causes and Risk Factors
Several underlying conditions and lifestyle factors can contribute to the development of heart failure with mildly reduced ejection fraction. Coronary artery disease, where the blood vessels supplying the heart muscle become narrowed or blocked, is a frequent cause. High blood pressure forces the heart to work harder to circulate blood, which can eventually weaken the muscle over time. Diabetes can also damage blood vessels and the heart muscle itself, increasing the risk.
Obesity places additional strain on the heart, requiring it to pump more blood to support a larger body mass. Certain heart rhythm problems, such as atrial fibrillation, can impair the heart’s coordinated pumping action. Valvular heart disease can impede blood flow or cause backflow, leading to increased workload and potential weakening of the heart muscle. A history of a heart attack also significantly elevates the risk for developing HFmrEF.
Diagnosis and Confirmation
Diagnosing heart failure with mildly reduced ejection fraction typically begins with a thorough physical examination and a detailed review of the patient’s medical history. The doctor will inquire about symptoms, past medical conditions, and family history of heart disease. An echocardiogram is a primary diagnostic tool, using sound waves to create images of the heart and directly measure the ejection fraction. This test also assesses heart chamber size and valve function.
An electrocardiogram (ECG or EKG) may be performed to record the electrical activity of the heart, detecting any abnormal rhythms or signs of past heart damage. Blood tests are also valuable, including measurements of natriuretic peptides like B-type natriuretic peptide (BNP). Elevated levels of these hormones can indicate increased pressure and stretch within the heart chambers. A chest X-ray might reveal fluid accumulation in the lungs or an enlarged heart, while a cardiac MRI can provide more detailed images of heart structure and function.
Management and Treatment Strategies
Managing heart failure with mildly reduced ejection fraction involves a comprehensive approach combining pharmacological treatments and lifestyle modifications. Diuretics are often prescribed to reduce fluid buildup, alleviating symptoms like swelling and shortness of breath. Medications such as angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) help relax blood vessels and lower blood pressure, easing the heart’s workload. Beta-blockers can improve heart function by slowing the heart rate and reducing its overall strain.
Mineralocorticoid receptor antagonists, like spironolactone or eplerenone, are often added to help block certain hormones that can worsen heart failure, potentially improving outcomes. A more recent class of medications, sodium-glucose cotransporter-2 (SGLT2) inhibitors, have shown benefits in improving heart failure symptoms and reducing hospitalizations across the spectrum of ejection fractions, including HFmrEF. These pharmacological interventions are typically tailored to the individual’s specific symptoms and overall health profile.
Beyond medications, lifestyle adjustments play a substantial role in managing HFmrEF. Dietary changes, particularly reducing sodium intake, are important for minimizing fluid retention and managing blood pressure. Regular, moderate exercise can improve heart health and overall physical conditioning. Weight management is also beneficial, as excess weight increases the heart’s workload.
Smoking cessation is strongly encouraged, as smoking significantly harms blood vessels and the heart. Limiting or avoiding alcohol consumption can also support heart health. These non-pharmacological strategies work in conjunction with prescribed medications to optimize heart function, alleviate symptoms, and improve the individual’s quality of life. Management is individualized, considering specific causes, symptom severity, and co-existing medical conditions.