Heart failure is a condition in which your heart doesn’t pump enough blood to meet your body’s needs or in which the heart doesn’t relax enough, and the pressures inside the chambers can rise. This can cause fatigue, breathing difficulties, and a buildup of fluid in your tissues.

An estimated 6.2 million adults in the United States have heart failure, reports the Centers for Disease Control and Prevention (CDC). Roughly half of those people have heart failure with preserved ejection fraction (HFpEF), where the heart doesn’t relax adequately. This is also known as diastolic heart failure.

Read on to learn about HFpEF and get the answers to common questions about treatments, outlook, and more.

Heart failure with preserved ejection fraction (HFpEF) is a type of heart failure that occurs when the muscle in the left ventricle stiffens and is less able to relax, so the pressure inside the heart rises. HFpEF is usually caused by coronary artery disease, valvular heart disease, diabetes, obesity, or hypertension.

To understand HFpEF, it helps to know how your heart works. Your heart is composed of four chambers:

  • the right atrium
  • the right ventricle
  • the left atrium
  • the left ventricle

The right atrium receives oxygen-depleted blood from the rest of your body and sends it to your right ventricle, which pumps the blood to your lungs to pick up oxygen.

The left atrium receives oxygen-rich blood from your lungs and sends it to your left ventricle, which pumps the blood to the rest of your body.

The movement of blood depends on the rhythmic relaxation and contraction of your heart chambers. This is known as the cardiac cycle.

Your heart chambers (called ventricles) relax during the diastole phase of the cardiac cycle, which allows the heart chambers to fill with blood. Your heart muscle contracts during the systole phase, which pumps the blood.

If you have HFpEF, your left ventricle becomes stiff and can’t relax properly. This prevents it from filling with enough blood during the cardiac cycle’s diastole phase, and the filling occurs with higher pressure, which reduces the amount of blood available to pump throughout the body during the systole phase and causes backup of fluid into the lungs and the body.

As a result, less oxygen-rich blood is delivered to your organs and other tissues. HFpEF, because of its high pressures, can also cause fluid to build up in your tissues, which is known as congestive heart failure.

Heart failure with reduced ejection fraction (HFrEF) is also known as systolic heart failure. It also affects the left ventricle but in different ways.

In HFrEF, the left ventricle is too weak rather than too stiff. It can’t contract properly. It may fill with enough blood during the cardiac cycle’s diastole phase, but it can’t pump that blood with enough force during the systole phase, so the amount of blood ejected (ejection fraction) is reduced.

Ejection fraction is a measurement that compares the amount of blood that fills your ventricle to the amount of blood that your ventricle pumps out with each contraction.

A normal ejection fraction is 55 to 70 percent. If your ejection fraction is below 50 percent, you may have HFrEF.

If you have HFpEF, you may actually have a normal ejection fraction. That’s because there’s less blood coming into the stiffened left ventricle, but your heart is still able to pump that blood back out of the ventricle.

Though the proportion of blood going into the proportion going out is normal, your body still isn’t getting enough oxygenated blood with each cardiac cycle.

Your doctor won’t be able to tell whether you have HFpEF and HFrEF based on your symptoms alone.

To measure your ejection fraction and diagnose the type of heart failure you have, your doctor may order tests such as:

  • echocardiogram
  • nuclear stress test
  • MUGA Scan
  • cardiac catheterization
  • CT scan

The treatment options for HFpEF are limited.

Your doctor may prescribe diuretics to limit fluid build-up in your tissues.

They may also prescribe treatments to manage other chronic health conditions or cardiovascular risk factors that you may have.

For example, they may prescribe medication to:

  • reduce your heart rate so that the heart spends more time in diastole (allowing more time for the heart to fill)
  • lower your blood pressure, if you have high blood pressure
  • reduce your cholesterol level, if you have high cholesterol
  • decrease your risk of blood clots, if you have atrial fibrillation
  • control your blood sugar, if you have diabetes

Your doctor may encourage you to make other lifestyle changes, including to:

  • lose weight
  • change your diet
  • adjust your exercise routine

Scientists are studying other treatments for HFpEF. The Food and Drug Administration (FDA) approved the drug combination sacubitril and valsartan (Entresto) in February 2021 for people with HFpEF.

Your doctor can help you learn about new treatment options as they become available or advise you if you qualify for a clinical trial testing new drugs for HFpEF.

Heart failure is a potentially life-threatening condition.

A 2017 study found that all people hospitalized with heart failure survived for a median of 2.1 years. Roughly 75 percent of people hospitalized with HFpEF in this study passed away within five years. Cardiovascular and HF readmission rates were higher in those with HFrEF than those with HFpEF.

Some people live for longer with HFpEF.

Your outlook depends on:

  • how severely your heart function is affected
  • how much fluid retention you have
  • your age and overall health
  • the treatment you receive

Many people with HFpEF have other health conditions and cardiovascular risk factors, such as:

  • high blood pressure
  • coronary artery disease
  • atrial fibrillation
  • chronic kidney disease
  • diabetes
  • obesity

These conditions and risk factors raise the risk of poor health outcomes.

Getting treatment for HFpEF and other chronic conditions may help improve your quality of life and outlook. Practicing healthy habits is also important.

Roughly half of people with heart failure have HFpEF.

This condition reduces the amount of oxygen-rich blood that your heart delivers to other tissues and organs and increases the pressure in your heart. It can cause uncomfortable symptoms and put you at risk of potentially life-threatening complications.

It’s important to get treatment for HFpEF and other chronic health conditions that you may have. Your doctor may prescribe medications and other treatments. They may also encourage you to make changes to your lifestyle to protect your heart and overall health.