Medical Knowledge 101: What Exactly Is Congestive Heart Failure?

Congestive heart failure (CHF) is a chronic, progressive condition in which your heart isn’t pumping the blood as well as it’s supposed to. Contrary to what the name might suggest, congestive heart failure doesn’t mean that your heart has stopped working, but that it’s not working well enough to meet your body’s demands.

One of the main characteristics of heart failure is congestion — or the build-up of fluid in tissues and veins in the lungs. Some people use the terms congestive heart failure and heart failure interchangeably, while others only use CHF when congestion is present.

The way your heart works and types of heart failure

Your heart is a strong, muscular pump, whose contractions keep blood circulating and delivering oxygen and nutrients to all the cells in your body. It has four chambers — two upper ones (called atria) receive the blood and then pass it to the two lower chambers (the ventricles), which pump it. Depending on the part of the heart that is affected, congestive heart failure can be left-sided, right-sided, or biventricular (affecting both ventricles).

The heart’s job is divided between the right and the left side, which work together as a team. Blood depleted from oxygen fills the right atrium and then goes to the right ventricle, which sends it to the lungs. The left side of the heart is responsible for receiving freshly oxygenated blood and distributing it through the circulatory system to the rest of the body. This is why the left ventricle is often called the heart's main pumping chamber. Special valves keep the blood flowing in one direction. These are like the door between the upper and lower chambers that don’t allow the blood to go back.

Left-ventricular heart failure is the most common type, and it can progress to cause the right-ventricle to failure as well. Regardless of which side of the heart is affected, problems can happen either while the heart is filling with blood (diastole), or when it’s contracting (systole). The first is called diastolic heart failure, and it can happen when the heart is stiff. Systolic heart failure, characterized by problems with how the ventricles contract, often happens when the heart is enlarged or weakened by another condition.

Why does heart failure happen and what causes it?

The main causes of congestive heart failure are:

• Coronary artery disease (CAD). This disease of clogged arteries is the number one cause of death in the world. It often goes without symptoms, but can cause a stroke and lead to heart failure in several ways. Stroke deprives heart cells of oxygen and causes some of them to die and be replaced by scar tissue, which interferes with the way your heart works. Some studies report that up to 70 percent of heart failure cases are caused by CAD.​
• Hypertension. High blood pressure happens when blood vessels narrow. You probably know from experience that it’s much harder to push something through a narrow pipe than through a wider one. This means that your heart also has to work harder to get the blood going when the blood vessels are narrow. Doing extra work for a long time leaves its trace on the muscle, and it gets less efficient in pumping blood. 
• Cardiomyopathy. Cardiomyopathy is a group of heart muscle diseases that cause changes in the structure of your heart muscle.

Other, less common causes of congestive heart failure include:

• Diabetes mellitus
• Congenital defects of the heart
• Arrhythmia (irregular heartbeats)
• Certain substances, including medications, supplements, psychoactive drugs and alcohol
• Lung disease
• Thyroid disease
• Viral infections, including HIV

What are the symptoms of congestive heart failure?

The main symptoms of heart failure include:

• Breathlessness. When the left ventricle is not pumping blood as it should, pressure in the heart rises and pushes fluid into the lungs. This disrupts the exchange of gases, leaving you with a feeling that you can’t get enough air. Some people also experience persistent coughing and wheezing.
• Swelling of the legs, feet, abdomen or other body parts. Due to fluid build-up in tissues. You might notice this as (unexplained) weight gain. 
• Fatigue that gets worse with time. Fatigue can have a lot of different causes, and it can often be something simple like lack of sleep. What’s characteristic of fatigue caused by heart failure is that it gets worse with time. Keeping a journal of daily energy levels can help you conclude if your fatigue is progressive.
• Arrhythmias (irregular heart rhythm). This may manifest as your heart skipping a beat, fluttering, or beating too fast.
• Dizziness and fainting happen when the brain is not getting enough oxygen, which can happen due to some of the above-mentioned symptoms like tachycardia or trouble breathing.

Are you at risk of developing congestive heart failure?

However, 1.4 out of 5.6 million of heart failure cases in the US are people younger than 60 years. Other than the mentioned diseases that can cause heart failure, your risk increases if:

• You’re a smoker
• You're obese
• You have a family history of heart disease
• You’re male
• You’re African-American

How is congestive heart failure diagnosed?

There is no gold standard for diagnosing heart failure. To make a diagnosis, your physician will use a combination of some of the following tests and procedures:

• Physical exam. This includes taking your medical history, weighing you, taking your blood pressure, and listening to your heart and lungs. The important part here is to be honest with your doctor about your habits like smoking and your diet.
• Blood work. Blood tests can show if one of your organs is not working as well as it should. Tests search for markers that can indicate stretching or damage of the heart cells or kidney damage, since they are also affected by heart failure. The UK's National Institute for Health and Care Excellence recommends first testing for brain natriuretic peptide which is released when your heart cells stretch. If the test is positive, imaging tests are next.
• Echocardiography (Echo, or heart ultrasound). This imaging technique allows your doctor to see your heart pumping blood as well as the thickness of its muscle walls. It’s used to measure ejection fraction, a very important parameter in heart failure that shows how much blood your left-ventricle is pumping out. An echo also shows your heart’s size and shape. A weakened heart, from coronary artery disease or hypertension, often has enlarged ventricles.
• Chest X-ray. This shows if there’s congestion in your lungs.
• Electrocardiogram (ECG/EKG). This test uses electrodes to record electrical activity in your heart, which can show if you have an arrhythmia.
• Cardiac MRI. Another imaging technique, it gives much more detailed pictures of your heart than an echo.

Occasionally, other tests like an exercise stress test or radionuclide ventriculography are done.

Your involvement matters: Treatment options for congestive heart failure

Congestive heart failure usually requires lifelong management of the symptoms, excluding rare examples in which heart failure can be reversed. However, medications and lifestyle changes can improve the symptoms of heart failure and sometimes even make the heart stronger. It can also prevent complications and allow you to live longer.

One of the most important factors for successful management is your willingness to commit and stick to changes in your diet and lifestyle, as well as regular check-ups and taking the meds you’ve been prescribed.

Treatment can include the following.

Medications

Physicians usually use a combination of some of the following meds:

• ACE inhibitors dilate your blood vessels, loweringh your blood pressure and making it easier for the heart to pump blood.
• Angiotensin II receptor blockers work on the same system as ACE inhibitors but with a different mechanism, and they’re usually used for people who are sensitive to ACE inhibitors.
• Beta-blockers can help lower your blood pressure, manage arrhythmia, and some have different cardio-protective properties.
• Diuretics (“water pills”) help remove excess water.
• Digoxin makes heart contractions stronger and can help with some arrhythmias.
• Inotropes are an intravenous treatment used for severe heart failure.

Devices

Some people will also require devices that help the heart beat normally and prevent dangerous complications of arrhythmias. Those include:

• Implantable cardioverter-defibrillators (ICDs), a small, battery-powered device that monitors and corrects your heart rhythm when needed by sending small electrical shocks.​
• Biventricular pacemakers are similar to ICDs, but constantly sends small electrical signals to both of your ventricles. As the name suggests, it dictates the pace at which your heart works. This is also called cardiac resynchronization therapy.
• Ventricular assist device (VADs) are implantable mechanical pumps used in late-stage heart failure. They help the heart pump blood.

Surgical procedures

• Coronary bypass surgery for patients with severely blocked arteries.
• Heart valve repair/replacement, if the cause of HF is a valve problem. 
• Heart transplant. This is the last option, but a patient needs to meet certain criteria to be eligible.