By Shamard Charles, MD, MPH 

 Medically reviewed by Jeffrey S. Lander, MD

The heart is the center of the circulatory system, and its main job is to provide nutrient-rich blood and oxygen to all the vital tissues of the body. It is divided into four chambers—two on the right side and two on the left side.

The right atrium receives oxygen-poor blood from two major veins, the inferior and superior vena cava, and sends it to the right ventricle, which pumps it to your lungs via the left and right pulmonary arteries. Here, it picks up oxygen and gets rid of carbon dioxide.

Oxygen-rich blood from the lungs enters the left ventricle, where it is pumped to the rest of the body by the aorta, the largest artery. The heart’s pumping process is called the cardiac cycle. On average one cardiac cycle pumps 5.6 liters (L) of blood throughout the body.¹

The left ventricle is the chamber that is responsible for pumping blood from the heart to the rest of the body. Dysfunction of the left ventricle leads to two types of heart failure: systolic and diastolic.

This article details the differences and similarities of systolic and diastolic heart failure.

How Common Is Heart Failure?

Heart failure is common in the United States, with over 6 million people living with this condition. Additionally, nearly 1 million new cases are diagnosed each year. Fortunately, medical advances have made it possible to manage heart failure.¹

Systolic and Diastolic Heart Failure Defined 

Both sides of the heart are prone to dysfunction, but heart failure on the left side is more common.

• Systolic heart failure occurs when the left side of the heart becomes too weak to squeeze normal amounts of blood out of the heart when it pumps.

• Diastolic heart failure occurs when the left side of the heart is too stiff to relax and fill normally with blood. 

The most common culprits of left-sided heart failure are:

• Heart attack

• Coronary artery disease

• Hypertension (high blood pressure)

While the right side of the heart is more commonly affected by:²

• Chronic obstructive pulmonary disorder (COPD)

• Rheumatic heart disease

Systolic Heart Failure

Systolic heart failure occurs when the left ventricle loses its ability to contract. In people with systolic heart failure, blood fills the left ventricle at normal levels, but it cannot be pumped in adequate amounts to support bodily functions. For this reason, systolic heart failure is also called heart failure with reduced ejection fraction (HFrEF). If the body’s tissues are deprived of oxygen, organ failure may ensue.

The most common causes of systolic heart failure are:³

• Coronary artery disease

• Hypertension

• Valvular heart disease (damage to the heart valves)

• Myocarditis (inflammation of the heart muscle)

• Cardiomyopathy (disease of the heart muscle affecting the pumping of blood)

• Obstructive sleep apnea (breathing stops during sleep)

Diastolic Heart Failure

Diastolic heart failure occurs when the left ventricle loses its ability to expand due to stiffness. The heart chamber also is unable to fill with enough blood during the resting periods of the cardiac cycle. As a result, there is less blood available to pump out of the heart. 

Because the heart does not lose the ability to contract, diastolic heart failure is also called heart failure with preserved ejection fraction (HFpEF). As you get older, the heart and blood vessels become less elastic, increasing your risk of developing diastolic heart failure.

Other causes of diastolic heart failure include:⁴

• Hypertension: Chronic hypertension is one of the most common causes of diastolic heart failure. High blood pressure over a long period of time means the heart has to work harder to pump blood throughout the body. As a result, the heart gets more muscular and stiffer. This impacts its ability to relax during the resting stages of the cardiac cycle, when the heart fills up with blood. 

• Diabetes: Diabetes can lead to stiffening of the heart wall and muscle.

• Coronary artery disease: Coronary artery disease decreases blood flow to the muscles of the heart, which may lead to diastolic dysfunction.

• Obesity: Obesity causes changes in the volume of the blood that fills the left ventricular and can possibly lead to stiffness in the left ventricle.

• Sedentary lifestyle: A lack of physical activity can put you at higher risk of high blood pressure, diabetes, coronary artery disease, and obesity, all of which contribute to diastolic heart failure. 

Symptoms and Diagnosis

Symptoms

Nearly 3% of Americans experience heart failure, and it is becoming more common in those over 65 years old.⁵ Knowing the signs and symptoms of heart failure can help you get an early diagnosis, which can be lifesaving.

If you experience any of the following symptoms of heart failure, seek immediate medical attention:⁶

• Chest pain

• Fatigue

• Shortness of breath, especially when moving

• Shortness of breath when lying down or during sleep

• Exercise intolerance (feeling extreme fatigue when exercising)

• Swelling of the feet, ankle, or legs

• Weight gain

• Nausea

• Persistent coughing or wheezing

The following is the New York Heart Association's classification system, which is the simplest and most widely used method to gauge symptom severity:

Class I

• No limitations of physical activity

• No heart failure symptoms

Class II

• Mild limitations of physical activity

• Heart failure symptoms with significant exertion (physical activity); comfortable at rest or with mild activity

Class III

• Marked limitations of physical activity

• Heart failure symptoms with mild exertion; only comfortable at rest

Class IV

• Discomfort with any activity

• Heart failure symptoms occur at rest

Diagnosis

During the initial evaluation of systolic or diastolic heart failure your healthcare provider or another healthcare professional will take a detailed history and perform the following:

• Physical examination

• Chest X-ray

• Electrocardiography (EKG, or ECG): An EKG tracks the electrical activity of the heart. Abnormal electrical activity can be a sign of heart failure, including heart attack or abnormal heart rhythm. 

• Lab tests: Blood work can detect chemicals in the heart and blood vessels that can indicate a recent heart attack or heart failure.

• Cardiac stress test: A cardiologist may ask you to run on a treadmill to assess your exercise tolerance. A stress test determines how well your heart performs during exercise, as chest pain or fatigue on exertion can indicate a shortage of blood supply to your heart caused by blockages in the coronary arteries.

• Cardiac catheterization: This measures how well the heart is functioning and provides pictures of the coronary arteries to look for blockages. During cardiac catheterization, a cardiologist inserts a thin, long tube called a catheter into the groin or arm and advances it to the heart to measure heart pressures, view arteries, and assess how the heart is functioning. 

Computed tomography (CT), magnetic resonance imaging (MRI), and nuclear scanning are other imaging tests that may also be used to look at the heart. 

Diagnosis of systolic heart failure is based on the following:

• Signs or symptoms of heart failure

• Reduced blood pumping from the left ventricle with each squeeze

Diagnosis of diastolic heart failure is based on the following:

• Signs or symptoms of heart failure

• Normal or mildly abnormal systolic left ventricle function

• Evidence of diastolic left ventricle dysfunction

Diagnosis of diastolic heart dysfunction can also be measured invasively, by inserting a catheter, or noninvasively, by using Doppler imaging (ultrasound) techniques.

Complications

Systolic and diastolic heart failure is a progressive condition that can lead to life-threatening complications if left untreated. The most common complications include:⁷

• Impaired kidney function: Decreased kidney function is common in those with heart failure, especially systolic heart failure. Heart failure can cause the kidneys, which are very sensitive to changes in blood flow and chemical imbalances, to not function properly due to a general lack of blood flow. Kidney disease can also worsen heart failure and, in severe cases, may require dialysis.

• Liver damage: In severe cases, fluid can back up from the heart into the liver, causing scarring and liver dysfunction. 

• Irregular heart rhythms (arrhythmias): Dysfunction of the heart muscle can lead to arrhythmias, which can make your symptoms worse. Some arrhythmias may also cause blood clots if the abnormal heartbeat makes blood pool in the left atrium. Clots can be dangerous because they can lead to heart attack, peripheral artery disease, or stroke. Some irregular heart rhythms may even be life-threatening.

• Right-sided heart failure: In severe left-sided heart failure, blood backs up into the right side of the heart and lungs. 

Risk Factors and Prevention

As previously mentioned, heart failure is more common as you age, but many other factors put you at risk. Fortunately, many of them can be modified. The primary risk factors for diastolic heart failure are:¹

• Poor diet

• Female gender

• Hypertension

• Coronary artery disease

• Diabetes

• Smoking

• Increased body mass index (BMI)

• Sedentary lifestyle 

Several other factors may contribute to developing systolic heart failure, including:

• Genetics (including birth defects of the heart and valve disease)

• Taking chemotherapy (drugs often used to treat cancer)

• Arrhythmias (abnormal heart rhythms)

• Cardiomyopathy (structural changes in the heart) 

• Myocarditis (damage to the heart muscle caused by infections)

Preventing heart failure is the key to living a happy and heart-healthy life. We now know that heart disease may begin as early as adolescence, even though we may not feel symptoms until much later in life. So, the sooner you adopt healthful behaviors, the better off you will be.

The American Heart Association and the U.S. Preventive Services Task Force recommend the following habits:⁸

• Regular physical activity

• Maintaining a healthy body weight

• Not smoking

• Eating fruits and vegetables

• Moderate alcohol intake

Treatment

In most people, heart failure is a chronic condition that requires lifelong treatment. Most treatments are geared toward slowing down the progression of your heart failure and managing your symptoms. 

Whether you have systolic or diastolic heart failure the key is to follow a treatment regimen that includes a combination of diet and lifestyle changes, medicines, and sometimes a device to protect your heart from abnormal rhythms.

The same lifestyle changes necessary for prevention also help manage your symptoms if you have heart failure, including:

• Regular low-intensity aerobic exercise to strengthen the heart

• Eating a heart-healthy diet

• Cutting back on salt (sodium)

• Limiting your alcohol consumption

• Quitting smoking

Treatment Options for Systolic Heart Failure 

Adequate treatment of systolic heart failure may require the use of one or several medications, including:⁷

• Diuretics, which help reduce fluid buildup in the body

• Angiotensin-converting enzyme (ACE) inhibitors, which help lower blood pressure and reduce strain on the heart. If you cannot tolerate ACE inhibitors, then angiotensin receptor blockers (ARBs) may be used in their place.

• Beta-blockers, to reduce the heart rate and blood pressure

• Sodium-glucose cotransporter 2 (SGLT2) inhibitors, which are used to treat diabetes but also can improve outcomes in people with heart failure

• Ivabradine (Corlanor), used to reduce heart rate

• Digoxin (Lanoxin), which lowers the heart rate and strengthens heart contractions

• Entresto, a combination medication that moderates blood pressure and keeps blood vessels from narrowing

Treatment Options for Diastolic Heart Failure 

While medicine hasn't been proven to benefit patients with diastolic heart failure, diuretics are commonly used to manage heart failure symptoms. They work by removing excess fluid from the body and slowing the heart down so it has more time to fill.⁷

The best way to manage diastolic heart failure is to treat its underlying causes, such as hypertension, diabetes, or coronary artery disease.

Frequently Asked Questions

What is the life expectancy of someone with systolic or diastolic heart failure? 

The prognosis of systolic and diastolic heart failure depends on many factors including:⁶

• Age

• The extent of left-sided heart failure

• Other medical conditions, like diabetes

• Prior hospitalizations

• How your body responds to medical treatments

• Exercise intolerance

Survival rates in patients with heart failure are 75.9% at one year, 45.5% at five years, and 24.5% at 10 years, compared to 97%, 85%, and 75% in the general population, respectively.⁹

Is it worse to have systolic or diastolic heart failure?

Many studies have concluded that systolic heart failure has a worse 10-year prognosis, but systolic and diastolic heart failure both carry a grim diagnosis, which is why it is important to lead a heart-healthy life.¹⁰

Is systolic or diastolic heart failure more common?

Compared with systolic heart failure, diastolic heart failure is seen more often in the elderly and women.¹¹

More research needs to be done on the prevalence of systolic and diastolic heart failure in different racial and ethnic groups.

Summary

Systolic heart failure occurs when the left side of the heart becomes too weak to squeeze normal amounts of blood out of the heart when it pumps. Diastolic heart failure occurs when the left side of the heart is too stiff to relax and fill normally with blood.