Heart failure

What is heart failure?

Heart failure a condition in which the heart cannot pump efficiently enough to meet the body's need for blood. The previous name for heart failure, congestive heart failure (CHF), refers to the buildup of fluid in the lungs (congestion) — a telltale sign of impaired heart function. However, the name CHF does not capture the variety of other symptoms that often occur, so the preferred term has been changed to simply heart failure (HF).

Contrary to its name, heart failure does not mean the heart has failed completely. Instead, the inefficient pumping associated with heart failure causes a backup of blood in the veins leading to the heart. The kidneys begin to retain fluid and the body's tissues swell. The swelling most commonly affects the legs. But it also can occur in other tissues and organs. When it occurs in the lungs, it causes breathing difficulty.

Types of heart failure

Impairments in pumping action can develop in the entire heart or just one side — left or right. Most heart failure is caused by left-sided problems: the left ventricle (the heart’s largest chamber) is either too weak or too stiff to pump normally.

In some people with heart failure, the left ventricle heart muscle becomes weaker. It cannot pump as well. This is known as systolic heart failure or heart failure with reduced ejection fraction (HFrEF).

In other people, the heart muscle becomes thick and stiff, leading to diastolic heart failure, also known as heart failure with preserved ejection fraction (HFpEF). In HFpEF, the left ventricle cannot fill with enough blood between heartbeats.

People can also have heart failure with some features of both weak heart muscle and stiff heart muscle, known as heart failure with mid-range ejection fraction (HFmrEF).

Heart failure symptoms

Many people with heart failure have symptoms they attribute to getting older, like fatigue, getting winded when walking stairs, or decreased exercise capacity. As the condition worsens, shortness of breath and wheezing occur even with walking on a flat surface. At late stages, shortness of breath starts to occur at rest.

As fluid accumulates in the lungs, people with heart failure may need to sleep propped up with pillows. This makes breathing easier. There also can be a persistent cough or wheeze due to fluid accumulation in the lungs.

Fluid also can collect in the legs and ankles, causing swelling. In people who are less active, collected fluid can accumulate in the abdomen. Some people urinate several times during the night as the kidneys drain off some of this excess fluid. As the body accumulates more and more fluid, the person may experience significant weight gain.

How is heart failure diagnosed?

Heart failure usually affects both sides of the heart. But in some people it affects only one side. When heart failure affects mainly the left side of the heart, the symptoms are more likely to involve breathing difficulties. When mainly the right side is affected, the main symptoms may be leg swelling and abdominal swelling.

Standard initial evaluation of suspected heart failure includes blood tests, a chest x-ray, and an echocardiogram (an ultrasound of the heart).

The echocardiogram is particularly important. It can determine whether the heart muscles have weakened or become stiff. Treatment can differ depending on the type of heart failure.

The echocardiogram can distinguish between the two types by measuring the ejection fraction (EF), which refers to the percentage of blood in the left ventricle (the heart’s main pumping chamber) that is pumped out each time the ventricle contracts.

For a healthy heart, a normal ejection fraction is 50% to 70%. A person with HFrEF typically has an EF of less than 40%.

In people with HFpEF, the heart muscles contract normally so the ejection fraction is normal or close to normal, at 50% or greater.

Men are more likely to have HFrEF, whereas HFpEF is about twice as common in women, particularly older women.

People with mid-range ejection fraction (HFmrEF) have a somewhat stiff heart that pumps less forcefully than normal. They tend to have an EF between 40% and 49%.

What causes heart failure?

Heart failure has many possible underlying causes, including:

• coronary artery disease
• high blood pressure (hypertension)
• heart valve disorders (including rheumatic heart disease)
• congenital heart disorders
• cardiomyopathy (disease of the heart muscle)
• heart attack
• cardiac arrhythmias (problems with the heart rate and/or rhythm)
• exposure to toxins, including excessive alcohol and certain chemotherapy drugs.

Hyperthyroidism, diabetes, obesity, and prolonged lung disease also increase the risk of heart failure.

Heart failure stages

Heart failure is defined by four stages, which usually progress over time.

Stage A: At risk for heart failure. This includes people who have normal heart structure but have risk factors for heart failure.

Stage B: Pre-heart failure. This includes people who have structural changes in their heart but have not shown any symptoms of heart failure.

Stage C: Symptomatic heart failure. This includes people with current or previous symptoms of heart failure.

Stage D: Advanced heart failure. This includes people with debilitating symptoms that affect their day-to-day function or require hospitalization.

Heart failure treatment

The treatment of heart failure focuses on:

• reducing symptoms
• decreasing hospitalizations
• improving life expectancy.

To help accomplish these goals, your doctor will advise a low-salt and fluid-restricted diet as well as medications.

For heart failure with reduced ejection fraction, medication treatment options include:

• a diuretic, which removes excess fluid from the body by increasing urine output
• an angiotensin-converting enzyme (ACE) inhibitor, angiotensin receptor blocker (ARB), or a combination drug containing sacubitril and valsartan (ARNI)
• a beta-blocker (bisoprolol, carvedilol, or metoprolol succinate have proven benefits for heart failure)
• a mineralocorticoid receptor antagonist (MRA) or ‘potassium-sparing diuretic’
• an SGLT2 inhibitor.

While diuretic medications relieve symptoms by removing excess fluid, the other drug classes listed above are referred to as guideline-directed medical therapy (GDMT). This group of medications reduce heart failure hospitalizations and reduce mortality in people with HFrEF.

Proven drug therapies for heart failure with preserved ejection fraction are more limited. The primary goal is keeping blood pressure well controlled and using diuretics as needed. Recent studies suggest adding an SGLT2 inhibitor can also reduce symptoms and help prevent hospitalization.

Your doctor also will address the underlying cause of your heart failure. Heart failure related to coronary artery disease may benefit from additional medications, angioplasty, or surgery. When heart failure is caused by a poorly functioning heart valve, your doctor may advise surgical repair and valve replacement.

For some heart failure patients, losing weight or avoiding alcohol can dramatically improve symptoms. Your doctor will tell you how much exercise is appropriate. Balancing physical activity with rest is important in more advanced stages of heart failure.

Eventually medications and self-treatment may no longer be helpful. At this point, a left ventricular assist device or heart transplant may be considered.

Can you prevent heart failure?

To avoid heart failure, you must prevent the various forms of heart disease that lead to it.

To prevent heart disease:

• Eat a healthy, balanced diet.
• Control your blood pressure and cholesterol level.
• Maintain a normal body weight.
• Exercise regularly.
• Don't smoke.
• Limit alcohol use to one to two drinks per day.

Some types of heart failure cannot be prevented.