Heart Failure - Terminology

Terminology

Heart failure is a global term for the physiological state in which cardiac output is insufficient in meeting the needs of the body and lungs. Often termed "congestive heart failure" or CHF, this is most commonly caused when cardiac output is low and the body becomes congested with fluid.

It may also occur when the body's requirements for oxygen and nutrients are increased and the demand outstrips what the heart can provide, (termed "high output cardiac failure"). This can occur from severe anemia, Gram negative septicaemia, beriberi (vitamin B₁/thiamine deficiency), thyrotoxicosis, Paget's disease, arteriovenous fistulae, or arteriovenous malformations.

Fluid overload is a common problem for people with heart failure but is not synonymous with it. Patients with treated heart failure will often be euvolaemic (a term for normal fluid status), or more rarely, dehydrated.

Medical professionals use the words "acute" to mean of rapid onset and "chronic" of long duration. Chronic heart failure is therefore a long term situation, usually with stable treated symptomatology.

Acute decompensated heart failure is exacerbated or decompensated heart failure, referring to episodes in which a patient can be characterized as having a change in heart failure signs and symptoms resulting in a need for urgent therapy or hospitalization.

There are several terms which are closely related to heart failure, and may be the cause of heart failure, but should not be confused with it:

• Cardiac arrest and asystole refer to situations in which there is no cardiac output at all. Without urgent treatment these result in sudden death.
• Myocardial infarction ("Heart attack") refers to heart muscle damage due to insufficient blood supply, usually as a result of a blocked coronary artery.
• Cardiomyopathy refers specifically to problems within the heart muscle, and these problems can result in heart failure. Ischemic cardiomyopathy implies that the cause of muscle damage is coronary artery disease. Dilated cardiomyopathy implies that the muscle damage has resulted in enlargement of the heart. Hypertrophic cardiomyopathy involves enlargement and thickening of the heart muscle.