What is heart failure?
Many people mistakenly believe that heart failure is an abrupt stopping of the heart. In fact, heart failure is a condition that usually takes place over time. It happens when the heart is not pumping properly because it is unable to contract or relax. As a result, the heart can’t pump enough blood to meet your body’s needs.
Typically, it is the lower chambers of the heart, also called the ventricles, that are the source of the inefficient beating.
Your heart tries to make up for the inefficient beating by increasing its muscle mass. This leads to an enlarged heart that, initially, does pump more blood. But eventually it requires more oxygen than it can get, leading to further damage. The walls of the heart stiffen, and the pumping becomes less efficient. The enlarged heart can also produce certain hormones that can further damage the heart.
Most often, heart failure begins with the left ventricle, which is your heart’s primary pumping chamber. But it also can involve the right side or both sides of your heart.
Types of Heart Failure
Following are the different types of heart failure:
Left-sided heart failure—This is the most common form of heart failure. The left ventricle supplies most of the heart’s pumping power. During left-sided or left ventricular heart failure, the left side of the heart must work harder to pump the same amount of blood.
There are two types of left-sided heart failure:
- Systolic failure—Occurs when the left ventricle loses its ability to contract normally. As a result, the heart can’t generate enough force to push an adequate amount of blood into circulation.
Diastolic failure—Occurs when the left ventricle loses its ability to relax normally because the muscle has become stiff and the heart can’t fill with enough blood during the resting period between each beat.
- Right-sided heart failure—This type of heart failure usually happens as a result of left-sided failure. When the left ventricle fails, increased fluid pressure is forced back through the lungs, damaging the heart’s right side. With the right side loss of pumping power, blood backs up in the veins, often causing swelling in the ankles and legs.
Classes of Heart Failure
There are four classes of heart failure as defined by the New York Heart Association. They are:
Class I (Mild)—There is no limitation of your physical activity. Ordinary activity does not cause you undue fatigue, palpitation or shortness of breath.
Class II (Mild)—There is slight limitation of your physical activity. You are comfortable at rest, but ordinary physical activity results in fatigue, palpitation or shortness of breath.
Class III (Moderate)—You have a marked limitation of your physical activity. You are comfortable at rest, but less than ordinary activity causes fatigue, palpitation or shortness of breath.
Class IV (Severe)—You are unable to carry out physical activity without shortness of breath. When at rest, you have symptoms that may include fatigue, cough, shortness of breath and chest pain. Symptoms worsen with physical activity.
Be aware of common heart failure symptoms
Learn what may have caused your heart failure
Find out about how a heart failure diagnosis is made
Last Reviewed: April 25, 2011 V-00304