Regurgitation is
blood flow
Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory system is controlled by homeostasis, homeostatic mechanisms of autoregulation, just as hydrau ...
in the opposite direction from normal, as the backward flowing of blood into the
heart
The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...
or between heart chambers. It is the
circulatory equivalent of
backflow
Backflow is a term in plumbing for an unwanted flow of water in the reverse direction. It can be a serious health risk for the contamination of potable water supplies with foul water. In the most obvious case, a toilet flush cistern and its wate ...
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:
#
Aortic regurgitation
Aortic regurgitation (AR), also known as aortic insufficiency (AI), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a conse ...
: the backflow of blood from the
aorta
The aorta ( ; : aortas or aortae) is the main and largest artery in the human body, originating from the Ventricle (heart), left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at ...
into the left
ventricle, owing to insufficiency of the aortic semilunar valve; it may be
chronic or
acute.
#
Mitral regurgitation
Mitral regurgitation (MR), also known as mitral insufficiency or mitral incompetence, is a form of valvular heart disease in which the mitral valve is insufficient and does not close properly when the heart pumps out blood. Section: Valvular He ...
: the backflow of blood from the left ventricle into the left
atrium, owing to insufficiency of the
mitral valve
The mitral valve ( ), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valves. It has two Cusps of heart valves, cusps or flaps and lies between the atrium (heart), left atrium and the ventricle (heart), ...
; it may be acute or chronic, and is usually due to mitral valve prolapse,
rheumatic heart disease
Valvular heart disease is any cardiovascular disease process involving one or more of the four valves of the heart (the aortic and mitral valves on the left side of heart and the pulmonic and tricuspid valves on the right side of heart). The ...
, or a complication of cardiac dilatation. See also
Mitral regurgitation
Mitral regurgitation (MR), also known as mitral insufficiency or mitral incompetence, is a form of valvular heart disease in which the mitral valve is insufficient and does not close properly when the heart pumps out blood. Section: Valvular He ...
.
#
Pulmonic regurgitation: the backflow of blood from the
pulmonary artery
A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the ''main pulmonary artery'' or ''pulmonary trunk'' from the heart, and ...
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
The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, at the superior portion of the right ventricle. The function of the valve is to allow blood to flow from the right atrium to the right vent ...
.
Regurgitation in or near the heart is often caused by valvular insufficiency (insufficient function, with incomplete closure, of the
heart valve
A heart valve is a biological one-way valve that allows blood to flow in one direction through the chambers of the heart. A mammalian heart usually has four valves. Together, the valves determine the direction of blood flow through the heart. Hea ...
s); for example,
aortic valve
The aortic valve is a valve in the heart of humans and most other animals, located between the left ventricle and the aorta. It is one of the four valves of the heart and one of the two semilunar valves, the other being the pulmonary valve. ...
insufficiency causes regurgitation through that valve, called aortic regurgitation, and the terms ''
aortic insufficiency
Aortic regurgitation (AR), also known as aortic insufficiency (AI), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a conse ...
'' and ''
aortic regurgitation
Aortic regurgitation (AR), also known as aortic insufficiency (AI), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a conse ...
'' are so closely linked as usually to be treated as
metonymically
Metonymy () is a figure of speech in which a concept is referred to by the name of something associated with that thing or concept. For example, the word "suit" may refer to a person from groups commonly wearing business attire, such as salespe ...
interchangeable.
Regurgitant fraction
Regurgitant fraction is the percentage of blood that regurgitates back through the
aortic valve
The aortic valve is a valve in the heart of humans and most other animals, located between the left ventricle and the aorta. It is one of the four valves of the heart and one of the two semilunar valves, the other being the pulmonary valve. ...
to the
left ventricle
A ventricle is one of two large chambers located toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in t ...
due to
aortic insufficiency
Aortic regurgitation (AR), also known as aortic insufficiency (AI), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a conse ...
, or through the
mitral valve
The mitral valve ( ), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valves. It has two Cusps of heart valves, cusps or flaps and lies between the atrium (heart), left atrium and the ventricle (heart), ...
to the
atrium due to
mitral insufficiency
Mitral regurgitation (MR), also known as mitral insufficiency or mitral incompetence, is a form of valvular heart disease in which the mitral valve is insufficient and does not close properly when the heart pumps out blood. Section: Valvular He ...
. It is measured as the amount of blood regurgitated into a cardiac chamber divided by the
stroke volume
In cardiovascular physiology, stroke volume (SV) is the volume of blood pumped from the ventricle (heart), ventricle per beat. Stroke volume is calculated using measurements of ventricle volumes from an Echocardiography, echocardiogram and subtra ...
.
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%.
Epidemiology
Tricuspid and mitral regurgitation
Tricuspid regurgitation is common and is estimated to occur in 65–85% of the population.
In The
Framingham Heart Study
The Framingham Heart Study is a long-term, ongoing cardiovascular cohort study of residents of the city of Framingham, Massachusetts. The study began in 1948 with 5,209 adult subjects from Framingham, and is now on its third generation of partic ...
presence of any severity of tricuspid regurgitation, ranging from trace to above moderate was in 82% of men and in 85.7% of women. Mild tricuspid regurgitation tend to be common and benign and in structurally normal tricuspid valve apparatus can be considered a normal variant.
Moderate or severe tricuspid regurgitation is usually associated with tricuspid valve leaflet abnormalities and/or possibly annular dilation and is usually pathologic which can lead to irreversible damage of
cardiac muscle
Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, the others being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall o ...
and worse outcomes due to chronic prolonged
right ventricular volume overload
Volume overload refers to the state of one of the Heart#Structure, chambers of the heart in which too large a volume of blood exists within it for it to function efficiently. Ventricle (heart), Ventricular volume overload is approximately equival ...
.
In a study of 595 male elite football players aged 18–38, and 47 sedentary non-athletes, it was found that 58% of the athletes had tricuspid regurgitation vs. 36% in non-athletes and mitral regurgitation was found in 20% football players and 15% in controls. Football players with tricuspid regurgitation had larger tricuspid annulus diameter, compared to athletes without tricuspid regurgitation. Athletes with tricuspid regurgitation also had enlarged right atrium diameter when compared to control group. In athletes with mitral regurgitation it was found they had larger mitral annulus diameter, compared to athletes without regurgitation. Also left atrium diameter was larger in athletes with mitral regurgitation.
See also
*
Stenosis
Stenosis () is the abnormal narrowing of a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture).
''Stricture'' as a term is usually used when narrowing ...
*
Valvular heart disease
Valvular heart disease is any cardiovascular disease process involving one or more of the four valves of the heart (the aortic and mitral valves on the left side of heart and the pulmonic and tricuspid valves on the right side of heart). The ...
References
{{Wiktionary, Regurgitation
Cardiology