Understanding Heart Failure

A doctor showing a cross-section model of a human heart to a patient.
You can take steps to slow heart failure and live well. At OHSU, we’ll work with you to develop a treatment plan tailored to your needs and wishes.

The words “heart failure” can be scary. But this condition is common and manageable. Treatment and lifestyle changes can help you live the best life possible.

It’s important to know:

  • Heart failure happens when the heart cannot pump enough blood and oxygen. It does not mean your heart has stopped beating.
  • Heart failure can take years to develop. It may improve or get more serious over time.
  • Diabetes, high blood pressure and other conditions can increase your risk of heart failure.
  • Heart failure care is highly individual. Your care team will give you options throughout your treatment.
  • Scientists, including experts at OHSU, are developing new ways to extend life for people with advanced heart failure.

What is heart failure?

Heart failure does not mean your heart has stopped working. It’s also not a single health issue. Instead, it’s a collection of conditions that keep your heart from pumping as it should.

Heart failure develops over time. Conditions such as narrowed arteries or high blood pressure can weaken the heart. Or they can cause the heart muscle to become stiff and not work as well.

Heart failure can be mild or severe. Treatment and lifestyle changes can help you manage your condition and continue doing the things you enjoy.

What happens in heart failure?

The heart muscle usually makes strong contractions (squeezes) to pump blood to organs and tissue. With heart failure, the walls of the heart become weak, stiff or enlarged.

This means:

  • Your heart may not pump enough blood.
  • Blood may back up in your veins.
  • Fluid may build up, causing swollen feet, ankles and legs (edema).
  • Fluid may collect in your lungs (pulmonary edema).
  • Your kidneys may not be able to process water and sodium.
  • Your body may not get enough blood, nutrients and oxygen.

When the heart’s weakness leads to fluid buildup (congestion) in the lungs and surrounding tissues, it’s called congestive heart failure.

Treatment for heart failure often starts with diet and exercise changes. It may include medication or an implantable device. In more advanced cases, your care team may consider a surgery or heart transplant.

At OHSU, you can expect world-class treatment for heart failure. This includes a deeply knowledgeable team of heart care specialists, advanced technology, robust support services and a skilled transplant team.

Who gets heart failure?

About 6 million American adults are living with heart failure, according to the U.S. Centers for Disease Control and Prevention.

Doctors diagnose about 550,000 new heart failure cases a year. It is more common among people 65 and older.

What causes heart failure?

Many conditions can contribute to heart failure. Your treatment will depend on what caused your heart muscle to weaken, and how slowly or quickly heart failure developed.

Conditions linked to heart failure include:

Cardiomyopathy: This disease of the heart muscle limits how well it pumps. Of the many types, dilated cardiomyopathy is the most common. It usually starts in the heart’s main pumping chamber. The muscle stretches and becomes thinner, causing the chamber to enlarge and pumping to weaken. Another type, ischemic cardiomyopathy, is caused by a heart attack or series of heart attacks.

Atherosclerosis: This occurs when fat, cholesterol and other substances (plaque) build up along the artery walls. This limits blood flow and can lead to a stroke or heart attack.

Other conditions:

  • Heart valve problems
  • Problems in the electrical (conduction) system that regulates heartbeat and rhythm
  • Genetic heart conditions
  • High blood pressure
  • Use of certain medications or recreational drugs
  • Some types of cancer

Heart failure risk factors

Having a risk factor doesn’t necessarily mean you will develop heart failure, and not having one doesn’t mean you won’t. Some are things you can control, and some aren’t.

Risk factors include:

  • Conditions such as:
    • Diabetes
    • High blood pressure
    • Obesity
    • Coronary artery disease
    • Valvular heart disease
  • Family history of heart failure or heart attacks
  • Smoking
  • Heavy drinking
  • A diet high in salt, fat and cholesterol
  • Not getting enough exercise

Lowering your risk

Changing your habits can make a big difference. Steps to reduce your risk or to slow heart failure include:

  • Quitting smoking
  • Cutting back on alcohol
  • Being physically active
  • Eating healthy foods that are low in salt, fat and cholesterol
  • Managing related health conditions such as diabetes and high blood pressure
  • Lowering and managing stress

Signs and symptoms of heart failure

Common symptoms include:

  • Shortness of breath
  • Tiredness
  • Bloating/swelling in your legs, ankles or abdomen
  • Coughing up white or pink mucus
  • Heart palpitations (when it feels like your heart is beating too hard, too fast, skipping a beat or fluttering)
  • Lack of appetite/upset stomach
  • Memory loss/confusion

Types of heart failure

Heart failure can affect the left side of the heart, the right side or both. It usually starts on the left side.

How the heart works

To understand types of heart failure, it helps to understand some basics about how the heart works.

The heart muscle pumps blood through the body:

  • The right side pumps oxygen-poor blood to the lungs, where it picks up oxygen.
  • The left side pumps oxygen-rich blood to the rest of the body to nourish organs and tissues.

The heart has four chambers:

  • A right atrium
  • A right ventricle
  • A left atrium
  • A left ventricle
A diagram illustrating a cross-section of the human heart's anatomy.
This graphic shows the heart’s main parts, including its four chambers (two atria and two ventricles) and four valves. It also shows the direction of blood flow.

The cycle of blood flow begins when oxygen-poor blood (deoxygenated blood) enters the right atrium. From there, it passes to the right ventricle, which pumps it into the pulmonary artery. It travels to the lungs, where it takes up oxygen.

Oxygen-rich blood returns from the lungs through the pulmonary veins. It passes through the left atrium and into the left ventricle, which pumps it into the aorta. The aorta, the body’s main artery, sends the blood to the rest of the body. The heart’s valves open and close as blood passes through to keep it flowing in the proper direction.

After the blood circulates through the body, it returns to the right side of the heart to begin the cycle again.

A diagram illustrating a cross-section of the human heart and the direction blood flows through it.
Blood flows through the right side of the heart, then to the lungs to pick up oxygen. It re-enters the heart on the left side, and travels to the aorta, which carries it to the rest of the body.

Left-sided heart failure

In this type, the left side of the heart works harder to pump the same amount of blood as a normal heart. It is often described by its “ejection fraction,” the amount of blood your heart pumps out with each beat. A normal ejection fraction is roughly 50% or more.

Heart failure with reduced ejection fraction: The left ventricle doesn’t contract properly, so the heart’s pumping action isn’t strong enough to circulate blood as it would normally. This condition is also known as systolic failure.

Heart failure with preserved ejection fraction: The muscle of the left ventricle becomes stiff and cannot relax normally. As a result, the heart can’t effectively fill with blood in the resting period between each heartbeat. This is also known as diastolic failure or diastolic dysfunction.

Right-sided heart failure

This type usually happens only along with left-sided heart failure. The right ventricle moves oxygen-poor blood from your heart back to your lungs to be resupplied with oxygen. When the left ventricle doesn’t work properly, it can cause this “used” blood to back up.

As fluid builds up, it weakens the right side’s ability to pump. Right-sided heart failure can lead to swelling in your ankles, legs and abdomen.

Heart failure stages

Doctors classify heart failure from least to most severe. This is a general overview of heart failure classes, based on the commonly used New York Heart Association (NYHA) Functional Classification system.

  • Class I: No symptoms while doing daily activities such as walking or climbing stairs.
  • Class II: Mild symptoms (shortness of breath, chest discomfort, fatigue) when doing ordinary activities.
  • Class III: Comfortable at rest, but symptoms get worse with even limited activity, such as walking short distances.
  • Class IV: Symptoms are present while at rest and become worse with any physical activity.

Another common system, developed by the American Heart Association and the American Academy of Cardiology, uses stages A, B, C and D:

  • Stages A and B: People don’t have heart failure but are at risk because of conditions such as coronary artery disease, high blood pressure or diabetes.
  • Stage C: People with heart failure symptoms and structural heart disease.
  • Stage D: People with severe heart failure that needs specialized treatment.

Advanced heart failure

When heart failure has reached Class IV or Stage D, it’s considered advanced. About 10% of Americans with heart failure fall into this category.

With advanced heart failure, common medications and lifestyle changes may no longer be as effective. The good news is, there are more options than ever. They include implantable devices, surgeries, advanced medications, transplants, and palliative care to help you manage symptoms.

At OHSU, our advanced heart care and transplant team will work with you and your family. The team will explain treatment options and develop a treatment plan for your needs and wishes.

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