Congestive Heart Failure Pathophysiology

Congestive heart failure (CHF), also known simply as heart failure, is a chronic disease in which the heart gradually weakens and becomes less efficient at pumping blood around the body. Heart failure affects approximately 6.5 million people in the United States, and it is one of the most common reasons for hospital admissions among older adults.

This article will discuss the causes of CHF, how it develops, and possible complications.

What is pathophysiology?

Pathophysiology is the study of functional changes that occur in a particular disease or condition. This includes the cause of the disease, the consequences of changes caused by the disease, and how it affects other diseases (accompanying or related conditions) that the person has at the same time.

What is the pathophysiology of heart failure?

Heart failure occurs when the structure of the heart muscle changes and cannot pump blood as efficiently as it should. When this happens, the blood backs up, and fluid may build up in the lungs or in the arms and legs.

What is ejection fraction?

Ejection fraction (EF) is a measurement your doctor uses to determine the type of heart failure and to assess the stage of heart disease.

Ejection fraction represents the percentage of blood pumped from the left ventricle when the heart contracts. As blood leaves the left ventricle, it enters the aorta, which carries oxygen-laden blood to the rest of the body.

In a healthy heart, the ejection fraction ranges from approximately 52%–74%. When the ejection fraction is below 52%, it is considered low. Your healthcare professional may use your ejection fraction to determine the severity of CHF.

What causes congestive heart failure?

CHF usually develops after an infection or other disease weakens the heart muscle. Conditions and risk factors that lead to heart failure include:

  • Hypertension is a condition in which the pressure of the blood against the walls of the blood vessels is too high. This condition can lead to other complications, such as heart disease, stroke, and kidney disease.
  • Older adults are more likely to develop heart failure.
  • Heart valve problems can cause problems with the way blood flows, either limiting the amount that can move forward or sending blood in the wrong direction.
  • Coronary artery disease is the buildup of plaque in the arteries that causes narrowing of the blood vessels and problems with blood flow.
  • A heart attack, also called a myocardial infarction, occurs when part of the heart muscle doesn’t get enough blood.
  • Congenital heart defects are conditions that affect the structure and function of a baby’s heart before birth.
  • Arrhythmias, also known as arrhythmias, are problems with how fast or how slow your heart beats. Irregular beating rhythms can also be a problem.
  • Uncontrolled diabetes with persistently high blood sugar levels can cause damage to tissues throughout the body, including the heart muscle.
  • Thyroid disease, whether too much or too little thyroid hormone, can cause problems with heart function.
  • Human immunodeficiency virus (HIV) attacks the immune system and is associated with an increased risk of developing heart failure.
  • Infections can damage the heart, especially rare types such as viral cardiomyopathy.
  • Substance use, such as heavy drinking, smoking, and cocaine use, increases the risk of heart failure.

type of heart failure

The two types of congestive heart failure include:

  • Heart failure with reduced ejection fraction (HFrEF), formerly known as systolic heart failure, occurs when the ejection fraction is 45% or less. A 2020 study review noted that approximately 50% of heart failure cases have a reduced ejection fraction. Other risk factors for HFrEF include male gender, age, cardiomyopathy, and other heart conditions.
  • Heart failure with preserved ejection fraction (HFpEF), formerly known as diastolic heart failure, refers to heart failure in people without significant changes in ejection fraction. Other risk factors for HFpEF include atrial fibrillation, pulmonary hypertension, high body mass index (BMI), and smoking.
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Another type of heart failure called right-sided heart failure may develop. However, this is a rarer condition with different causes and symptoms.

Stages of Congestive Heart Failure

CHF is usually an irreversible disease that gets worse over time. The stage of heart failure describes the severity of the condition. According to the American College of Cardiology, the following are the four stages of heart failure:

  • Stage A: People are at high risk for heart failure but have no symptoms or changes in heart function. Such people usually have one or more diseases that can cause CHF.
  • Stage B: People with stage B CHF have changes in heart function but no symptoms of heart failure. Ejection fraction may be below the normal range.
  • Stage C: During this stage, people experience decreased heart function and current or previous symptoms of heart failure.
  • Stage D: In stage D, people have persistent CHF symptoms. if they have heart failure with reduced ejection fraction. Ejection fraction will be significantly reduced.

Symptoms and consequences of CHF

Signs and symptoms of heart failure may include:

  • shortness of breath when lying flat or moving
  • fatigue
  • weakness
  • arrhythmia
  • nausea and vomiting
  • problem concentration
  • cough or wheeze
  • swelling of the abdomen, feet, ankles, or legs (edema)

As CHF progresses, you may notice that exercising and completing normal, daily tasks become more and more challenging. Even walking through your home can become difficult due to problems with the passage of oxygen through your body.

Accompanying condition

Other conditions that often accompany the development of heart failure include:

  • Kidney disease: a progressive disease in which the kidneys become less effective at filtering waste
  • Diabetes: A disease that causes high blood sugar
  • Chronic Obstructive Pulmonary Disease (COPD): A disease that causes problems with the flow of air in the lungs and the exchange of oxygen and carbon dioxide
  • Obstructive Sleep Apnea (OSA): A condition in which the air gets blocked during sleep, causing the breathing to stop


Heart failure occurs when the heart muscle is injured and cannot contract effectively to allow blood to flow throughout the body. Damage to the heart can be due to coronary artery disease, high blood pressure, smoking, alcoholism, diabetes, infection, or other conditions.

As the heart gradually weakens, various symptoms develop, including shortness of breath, weakness, fatigue, and edema. Other diseases that commonly occur with CHF include diabetes, chronic obstructive pulmonary disease, sleep apnea, and kidney disease.

VigorTip words

Congestive heart failure can be a chronic disease that affects your life in many ways. Still, with an effective treatment plan, you can slow the progression of the disease.

If you find it challenging to manage the situation yourself, consider joining a support group to connect with others with CHF. Seek referrals from your healthcare professional or get in touch through organizations like the American Heart Association.

Frequently Asked Questions

  • What are the causes of congestive heart failure?

    Common causes of congestive heart failure include coronary artery disease, high blood pressure, smoking, alcoholism, diabetes, and infections.

  • What are the stages of congestive heart failure?

    The four stages of congestive heart failure include:

    • Stage A: High Risk for CHF
    • Stage B: Asymptomatic worsening of heart function
    • Stage C: worsening cardiac function and occasional symptoms
    • Stage D: Severe symptoms and poor cardiac function.
  • What are the common complications of congestive heart failure?

    Diabetes, chronic obstructive pulmonary disease, sleep apnea, and kidney disease are the most common diseases that occur with congestive heart failure.