Full Answer
What is the pathophysiology of a bruit?
The sound may originate from a local narrowing or dilation of the vessel itself, or it may be transmitted along the artery from a more proximal lesion in the vascular system. The intensity and duration of the bruit relate to the degree of vessel wall distortion. In general, bruits are not audible until an artery is approximately 50% occluded.
What is a a bruit?
A bruit is an audible vascular sound associated with turbulent blood flow. Although usually heard with the stethoscope, such sounds may occasionally also be palpated as a thrill.
What determines the characteristics of a carotid artery bruit?
The extent of collateral circulation around a critical stenosis influences the characteristics of a bruit. With internal carotid artery stenosis, for example, collateral formation is usually limited, and the character and timing of a bruit correlate rather closely with the degree of stenosis.
When are bruits audible?
In general, bruits are not audible until an artery is approximately 50% occluded. The sound increases in pitch as the lumen becomes more narrowed to a critical size. Thereafter, the sound may no longer be detectable as the volume of blood flow becomes greatly reduced.
What is the most likely cause of a bruit?
Atherosclerosis is the most common cause of a carotid bruit. Atherosclerosis is a medical term that refers to the buildup of plaque (a fatty substance) in arteries throughout your body. This plaque narrows the lumen (opening) of your arteries, limiting blood flow.
What does it mean to have a bruit?
A bruit is an audible vascular sound associated with turbulent blood flow. Although usually heard with the stethoscope, such sounds may occasionally also be palpated as a thrill.
What does positive bruit mean?
The presence of a bruit suggests stenosis or disruption of normal blood flow, such as through a tortuous vessel (Bickley et al., 2021). It is often described as a “whooshing” sound.
What causes carotid Bruits?
Carotid bruits generally result from turbulent, non-laminar flow through a stenotic lesion, which causes arterial wall vibrations distal to the stenosis. The vibrations are transmitted to the body surface, where they can be detected with a stethoscope.
What does it mean if you hear a bruit?
Bruits are blowing vascular sounds resembling heart murmurs that are perceived over partially occluded blood vessels. When detected over the carotid arteries, a bruit may indicate an increased risk of stroke; when produced by the abdomen, it may indicate partial obstruction of the aorta or…
Where are bruits heard?
If bruits are present, you'll typically hear them over the aorta, renal arteries, iliac arteries, and femoral arteries. The bell of the stethoscope is best for picking up bruits. The diaphragm is more attuned to relatively high-pitched sounds; the bell is more sensitive to low-pitched sounds like bruits.
What is the significance of the presence of an abdominal bruit in abdominal aortic aneurysm?
The presence of an abdominal bruit may suggest turbulent flow which may occur with an aneurysm. The presence of pulsatile popliteal masses bilaterally may not diagnose a AAA directly but the presence of bilateral popliteal artery aneurysms may suggest an increased incidence of AAA.
What does an abdominal bruit indicate?
An abdominal bruit is a swishing, or washing machine like sound heard when the diaphragm of stethoscope is placed over the spleen, renal arteries, or abdominal aorta. It is often indicative of partial occlusion of a vessel, as can be observed in renal artery stenosis or atherosclerosis of the abdominal vasculature.
Can a bruit be normal?
The carotid bruit can be a normal finding in a healthy person with no disease, or it can be an indication of severe carotid artery stenosis, a harbinger of impending stroke. It is therefore difficult to know what to do for patients with this finding.
Are carotid bruits common?
Carotid bruits are detected in 4% to 5% of the population aged 48 to 80 years and are associated with internal carotid artery stenosis in 50% of cases. Other causes of carotid bruits include increased venous flow, external carotid artery stenosis, and transmitted cardiac murmur.
What is the difference between a bruit and a thrill?
A bruit (a rumbling sound that you can hear) A thrill (a rumbling sensation that you can feel)
What are symptoms of carotid bruit?
Your doctor may notice an atypical sound called a bruit when listening to your pulse. This faint whistling sound is a distinctive sign of a carotid artery blockage. As the condition advances, the most common first sign of carotid artery disease may be a transient ischemic attack (TIA), also called a mini-stroke.
What is the difference between a bruit and a murmur?
When normal laminar blood flow within the heart is disrupted, an audible sound is created by turbulent blood flow. Outside of the heart, audible turbulence is referred to as a bruit, whereas inside the heart it is called a murmur. A pictorial representation of systolic and diastolic murmurs is below.
What does an abdominal bruit indicate?
An abdominal bruit is a swishing, or washing machine like sound heard when the diaphragm of stethoscope is placed over the spleen, renal arteries, or abdominal aorta. It is often indicative of partial occlusion of a vessel, as can be observed in renal artery stenosis or atherosclerosis of the abdominal vasculature.
What is the difference between a bruit and a thrill?
A bruit (a rumbling sound that you can hear) A thrill (a rumbling sensation that you can feel)
What does a thyroid bruit mean?
A thyroid bruit is described as a continuous sound that is heard over the thyroid mass. (If you only hear something during systolic, think about a carotid bruit or radiating cardiac murmur.) A thyroid bruit is seen in Grave's disease from a proliferation of the blood supply when the thyroid enlarges.
What does aortic bruit mean?
Bruits are blowing vascular sounds resembling heart murmurs that are perceived over partially occluded blood vessels. When detected over the carotid arteries, a bruit may indicate an increased risk of stroke; when produced by the abdomen, it may indicate partial obstruction of the aorta or…
Is abdominal aorta bruit normal?
A. Bruits occur in 4% to 20% of healthy persons. Abdominal bruits are more common in those younger than 40 years than in older persons. Characteristically, the abdominal bruit of a healthy individual is systolic, medium- to low-pitched, and audible between the xiphoid process and umbilicus.
Can you Auscultate the aorta?
To auscultate the aorta, place the stethoscope between the xiphoid (epigastrium) and the umbilicus about two-thirds of the way down.
Where do you Auscultate abdominal bruits?
Auscultation for abdominal bruits is the next phase of abdominal examination. Bruits are "swishing" sounds heard over major arteries during systole or, less commonly, systole and diastole. The area over the aorta, both renal arteries. and the iliac arteries should be examined carefully for bruits.
What is bruit in the neck?
Bruits and Hums of the Head and Neck - Clinical Methods - NCBI Bookshelf. A bruit is an audible vascular sound associated with turbulent blood flow. Although usually heard with the stethoscope, such sounds may occasionally also be palpated as a thrill. In the head and neck, these auscultatory sounds may originate in the heart ...
Why is bruit important?
Head and neck bruits loom especially important today because physicians encounter arterial occlusive disease more frequently as a greater proportion of our population lives longer. A bruit is an audible vascular sound associated with turbulent blood flow. Although usually heard with the stethoscope, such sounds may occasionally also be palpated as ...
Why is it important to trace proximally the audibility of an arterial sound?
Because a bruit may be auscultated directly over a stenosis, or distally in the direction of the blood jet producing the vibrations, it is important to trace proximally the audibility of an arterial sound to determine the exact anatomic site of the flow disturbance.
How to perform cervical auscultation?
At the outset of cervical auscultation, the carotid arteries are lightly palpated individually and then simultaneously to acquire a "feel" for the examination to follow. This palpation must be gentle so as to avoid inadvertent carotid sinus pressure and massage. Then carotid artery auscultation is initiated with the patient either supine or sitting. In the latter position, approaching the patient from behind allows optimal simultaneous carotid palpation and auscultation. The patient's chin points straight ahead, and the stethoscope bell is applied to achieve a skin seal over the course of each carotid artery. Simultaneous with auscultation, the examiner's free hand lightly rests on the contra-lateral carotid artery for timing purposes. Then the patient is asked to inspire deeply and hold the breath (without Valsalva) for 15 to 30 seconds. Auscultation continues during and immediately after breath holding. Holding the breath not only eliminates breath sounds that make hearing a bruit difficult but also accentuates an internal carotid bruit (see Basic Science). With the patient holding his breath, the examiner next compresses the contralateral common carotid artery slightly to determine whether this alters the length or intensity of a bruit. Remember that transient focal cerebral ischemia has been reported from digital pressure on neck carotid arteries, so diagnostic carotid palpation is probably contraindicated in a patient with preexistent brain ischemia. Finally, the examiner combines patient breath holding with simultaneous compression of both the ipsilateral superficial temporal and facial arteries (Figure 18.2). This last maneuver may be accomplished from behind or while facing the patient.
What is compression of arterial side branches?
In the second category (side branch factors), compression of arterial side branches should augment a bruit in the main artery and diminish a side branch bruit, whereas augmentation of flow through a side branch would have the opposite effect. This concept is especially applicable for evaluation of carotid artery bruits.
What is supraclavicular bruit?
Supraclavicular bruitsduring systole are a frequent finding in normal children and in adults with subclavian or vertebral artery stenosis. Supraclavicular auscultation is usually initiated to evaluate vertebral artery occlusive symptoms, arm claudication, or "subclavian steal" in the adult with atherosclerosis.
What is the lumen diameter of a soft systolic bruit?
A soft early systolic bruit is noted with a lumen diameter of 50%. As the obstruction increases to 60%, the bruit becomes high pitched, more intense, and holosystolic. At 70 to 80% diameter reduction, a pressure gradient may remain even during diastole, and the bruit is auscultated in both systole and early diastole.
How does bruit relate to the degree of vessel wall distortion?
The intensity and duration of the bruit relate to the degree of vessel wall distortion. In general, bruits are not audible until an artery is approximately 50% occluded. The sound increases in pitch as the lumen becomes more narrowed to a critical size.
Which hand is used to examine brachial artery?
The examiner's right hand is then curled over the anterior aspect of the elbow to palpate along the course of the artery just medial to the biceps tendon and lateral to the medial epicondyle of the humerus. The position of the hands should be switched when examining the opposite limb (Figure 30.1).
Why is pulse examination important?
Examination of the pulse can provide clues to the presence of systemic diseases. Ancient physicians would diagnose heart, liver, renal, and gastrointestinal problems from assessment of the pulse. Today, other tests have been developed to assist in the work-up of systemic illness, but examination of the pulse is still an important part of patient assessment.
Can a supine patient be palpated?
With the patient supine, the veins of the extremities usually cannot be palpated but can be examined by inspection. Phlebitis most commonly occurs in the superficial arm veins and the deep veins of the lower extremity.
Is it ok to use the thumb for pulses?
In general, it is inadvisable to use the thumb in pal pating for peripheral pulses. The thumb carries a greater likelihood of confusion with the examiner's own pulse and generally has less discriminating sensation than the fingers. Frequently, inspection will be an aid to pulse location.
Is arm vein phlebitis palpable?
Arm vein phlebitis is suggested by noting erythema occurring along the course of the vein, which may be tender to palpation if secondary venous thrombosis has occurred; this may be palpable (i.e., a "cord").
What is carotid bruit?
Carotid bruits are indicators of vascular disease in the cerebral circulation and, as expected, are associated with a twofold to threefold increase in the risk of stroke. From: Stroke (Fifth Edition), 2011. Download as PDF. About this page.
Where is the bruit loudest?
Focal. The bruit is often loudest at the bifurcation high in the neck and inaudible at the base . Osler said that the murmur of mitral stenosis is often limited to the region of a dime; the same explanation is valid for the focality of a localized region of carotid artery stenosis.
What is the risk of a stroke with carotid bruit?
Patients with asymptomatic carotid bruits have a slightly elevated risk of stroke. The annual risk of unheralded stroke (i.e., stroke without preceding transient ischemic attack [TIA]) in these patients is 1.5% to 4%, but many of these strokes occur contralateral to the side of the bruit and are related to other mechanisms of stroke, such as penetrating artery disease or cardioembolism.
How to detect asymptomatic carotid stenosis?
Asymptomatic carotid stenosis is sometimes detected on physical examination by detection of a carotid bruit. The presence of a carotid bruit increases the risk of stroke and transient ischemic attacks. In a large multiethnic study of asymptomatic subjects bruits were present in 4.1% of the population. Sensitivity of the bruit to detect carotid artery stenosis was 56%, specificity was 98%; positive predictive value was only 25% and the negative predictive value was 99% [6]. Thus, absence of a bruit does not exclude carotid stenosis. Also, in today’s era of intensive medical management, the benefit of detection of asymptomatic carotid stenosis does not outweigh the risk of early revascularization for stenosis. Therefore, referring every patient with a bruit for a carotid artery evaluation may not be an effective practice [7].
What is the loudest noise in the neck?
Venous noises usually are low-pitched rumbles that are continuous through diastole and often change with body position or Valsalva. Cardiac murmurs are loudest below the clavicle and fade away as one auscultates up the neck. Subclavian bruits are loudest in the supraclavicular fossa or at the base of the neck and may disappear with light supraclavicular compression. Bruits from cervical vertebral artery stenosis are uncommon but can occasionally be heard in the posterior neck triangle. The absence of a carotid bruit does not rule out the diagnosis of carotid occlusive disease; for example, a bruit may not be heard if there is low flow through a tight stenosis or if the internal carotid artery is occluded. In the latter case, a contralateral orbital bruit may be heard because of increased flow through the contralateral internal carotid artery.
How to check for atherosclerosis?
Examination of the available systemic and extracranial arteries may give clues to the presence of atherosclerosis or diminished flow not detectable by history. Note the pulse for at least a minute, seeking any irregularities. Feel the radial pulses simultaneously, looking for a significant difference in the strength of the pulses or a delay on one side. In all reported examples of subclavian steal, the diminished blood flow to the arm related to subclavian artery occlusive disease produced a definite pulse alteration. 47,48 The radial pulse is smaller and delayed on the ischemic side. If the pulses are equal and synchronous, it is not necessary to check the blood pressures in each arm. Feel the femoral and foot pulses and listen to the femoral region for an arterial bruit. Remember that some patients with a hyperdynamic circulation (e.g., fever, anemia, or hyperthyroidism) have bruits over many peripheral vessels. When a femoral bruit is present, listen over the antecubital and supraclavicular fossas to determine whether bruits are a generalized phenomenon and do not necessarily indicate focal disease.
What are the symptoms of CAS?
Patients with CAS may develop cerebrovascular ischemia due to a variety of pathophysiologic mechanisms, including atherosclerotic plaque rupture leading to acute thrombotic occlusion, thromboembolism, atheroembolism, arterial dissection, and hypoperfusion in the setting of a stenotic lesion. Arterial embolism to the distal cerebrovascular circulation is the most common event leading to cerebrovascular ischemia. Although a carotid bruit has relatively poor sensitivity in detecting a hemodynamically significant carotid stenosis, it is a strong marker of systemic atherosclerosis with associated increased risk of stroke, myocardial infarction, and cardiovascular death.
What is the most common cause of abdominal aortic aneurysms?
Less frequent causes include Marfan and Ehlers-Danlos syndromes, collagen vascular diseases, and mycotic aneurysm. Patients who have a first-degree relative with AAA are at increased risk.
What is the name of the artery that a AAA can rupture into?
AAAs may rupture into the vena cava , producing large arteriovenous fistulae. In this case, symptoms include tachycardia, congestive heart failure (CHF), leg swelling, abdominal thrill, machinery-type abdominal bruit, renal failure, and peripheral ischemia. Finally, an AAA may rupture into the fourth portion of the duodenum. These patients may present with a herald upper gastrointestinal bleed followed by an exsanguinating hemorrhage.
What is an AAA in a CT?
CT demonstrates abdominal aortic aneurysm (AAA). Aneurysm was noted during workup for back pain, and CT was ordered after AAA was identified on radiography. No evidence of rupture is seen.
What are the symptoms of a ruptured AAA?
Persons with AAAs that have ruptured may present in many ways. The most typical manifestation of rupture is abdominal or back pain with a pulsatile abdominal mass. However, the symptoms may be vague, and the abdominal mass may be missed.
Why is it so common to misdiagnose a renal artery?
The leading misdiagnosis is renal colic; dissection of the renal artery may produce flank pain and hematuria.
Why does my back hurt?
Back pain can be caused by erosion of the AAA into adjacent vertebrae. Other symptoms include abdominal pain, groin pain, embolic phenomena affecting the toes (eg, livedo reticularis, or blue toe syndrome; see the image below), and fever. Occasionally, small AAAs thrombose, producing acute claudication.
What pulses should be palpated for a femoral pedis?
Femoral/popliteal pulses and pedal (dorsalis pedis or posterior tibial) pulses should be palpated to determine if an associated aneurysm (femoral/popliteal) or occlusive disease exists. Flank ecchymosis (Grey Turner sign) represents retroperitoneal hemorrhage.