Bruit, also called vascular murmur, is the abnormal sound generated by
turbulent flow
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by Chaos theory, chaotic changes in pressure and flow velocity. It is in contrast to laminar flow, which occurs when a fluid flows in parallel layers with no disrupt ...
of blood in an artery due to either an area of partial obstruction or a localized high rate of blood flow through an unobstructed artery.
The bruit may be heard ("
auscultated") by securely placing the head of a
stethoscope
The stethoscope is a medicine, medical device for auscultation, or listening to internal sounds of an animal or human body. It typically has a small disc-shaped resonator that is placed against the skin, with either one or two tubes connected t ...
to the skin over the turbulent flow, and listening. Most bruits occur only in
systole
Systole ( ) is the part of the cardiac cycle during which some chambers of the heart contract after refilling with blood. Its contrasting phase is diastole, the relaxed phase of the cardiac cycle when the chambers of the heart are refilling ...
, so the bruit is intermittent and its frequency dependent on the heart rate. Anything increasing the blood flow velocity such as
fever
Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...
,
anemia
Anemia (also spelt anaemia in British English) is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin availabl ...
,
hyperthyroidism
Hyperthyroidism is a endocrine disease in which the thyroid gland produces excessive amounts of thyroid hormones. Thyrotoxicosis is a condition that occurs due to elevated levels of thyroid hormones of any cause and therefore includes hyperth ...
, or
physical exertion, can increase the amplitude of the bruit.
Etymology
It is naturalized from the French word for "noise", although another notes that and are also common,
and others give only for the cardiac sense.
Associated terms
Describing location of a partial obstruction
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Peripheral vascular disease
Peripheral artery disease (PAD) is a vascular disorder that causes abnormal narrowing of arteries other than those that supply the heart or brain. PAD can happen in any blood vessel, but it is more common in the legs than the arms.
When narro ...
; femoral artery stenosis
*
Renal artery stenosis
*
Stroke
Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...
,
carotid artery stenosis
Carotid artery stenosis is a narrowing or constriction of any part of the carotid artery, carotid arteries, usually caused by atherosclerosis.
Signs and symptoms
The common carotid artery is the large artery whose Common carotid artery#Clinical ...
*
Aortic aneurysm
An aortic aneurysm is an enlargement (dilatation) of the aorta to greater than 1.5 times normal size. Typically, there are no symptoms except when the aneurysm dissects or ruptures, which causes sudden, severe pain in the abdomen and lower back ...
*
Tinnitus
Tinnitus is a condition when a person hears a ringing sound or a different variety of sound when no corresponding external sound is present and other people cannot hear it. Nearly everyone experiences faint "normal tinnitus" in a completely ...
– a symptom which may be caused by a cranial artery bruit
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Arteriovenous malformation
An arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system. Usually congenital, this vascular anomaly is widely known because of its occurrence in the central nervous system (usually ...
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Coarctation of the aorta
Coarctation of the aorta (CoA) is a congenital condition whereby the aorta is narrow, usually in the area where the ductus arteriosus ( ligamentum arteriosum after regression) inserts. The word ''coarctation'' means "pressing or drawing toget ...
*
Hepatocellular carcinoma
Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults and is currently the most common cause of death in people with cirrhosis. HCC is the third leading cause of cancer-related deaths worldwide.
HCC most common ...
*
Alcoholic hepatitis
Describing the mechanism of a partial obstruction
*
Atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. This is a chronic inflammatory disease involving many different cell types and is driven by eleva ...
(
atheroma
An atheroma, or atheromatous plaque, is an abnormal accumulation of material in the tunica intima, inner layer of an arterial wall.
The material consists of mostly macrophage, macrophage cells, or debris, containing lipids, calcium and a variabl ...
or plaque) (cholesterol deposition in artery wall)
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Median arcuate ligament syndrome,
celiac artery stenosis – external compression
Describing location of localized high blood flow
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Arteriovenous (AV) fistula – pathologic or surgically created
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Graves' disease
Graves' disease, also known as toxic diffuse goiter or Basedow's disease, is an autoimmune disease that affects the thyroid. It frequently results in and is the most common cause of hyperthyroidism. It also often results in an enlarged thyro ...
,
goitre
*
Paget's disease
Unclassified
*
Polymyalgia rheumatica
Polymyalgia rheumatica (PMR) is a systemic inflammatory disease characterized by pain or stiffness, usually in the neck, shoulders, upper arms, and hips, but which may occur all over the body. Almost all cases occur in people age 50 or older. ...
*
Giant cell arteritis
Giant cell arteritis (GCA), also called temporal arteritis, is an inflammatory autoimmune disease of large blood vessels. Symptoms may include headache, pain over the temples, flu-like symptoms, double vision, and difficulty opening the mout ...
*
Fibromuscular dysplasia
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IgG4-related disease
See also
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Carotid bruit
*
Souffle
References
External links
American Heart Organization
{{Cardiovascular system symptoms and signs
Symptoms and signs: Vascular