Regurgitation (circulation)

Regurgitation is

blood flow in the opposite direction from normal, as the backward flowing of blood into the heart or between heart chambers. It is the circulatory equivalent of backflow

in engineered systems. It is sometimes called reflux.

Types of heart valve regurgitation

The various types of heart valve regurgitation via insufficiency are as follows:

acute

.

rheumatic heart disease, or a complication of cardiac dilatation. See also Mitral regurgitation
.

Pulmonic regurgitation: the backflow of blood from the pulmonary artery
into the right ventricle, owing to insufficiency of the pulmonic semilunar valve.

Tricuspid regurgitation: the backflow of blood from the right ventricle into the right atrium, owing to imperfect functioning (insufficiency) of the tricuspid valve.

Regurgitation in or near the heart is often caused by valvular insufficiency (insufficient function, with incomplete closure, of the

aortic insufficiency and aortic regurgitation are so closely linked as usually to be treated as metonymically

interchangeable.

Regurgitant fraction

Regurgitant fraction is the percentage of blood that regurgitates back through the

mitral insufficiency. It is measured as the amount of blood regurgitated into a cardiac chamber divided by the stroke volume

.

This fraction affords a quantitative measure of the severity of the valvular lesion. Normally, no blood regurgitates, so the regurgitant fraction is zero. In patients with severe valvular lesions, regurgitant fraction can approach 80%.