When auscultating the carotid arteries with the bell of a stethoscope a bruit is heard the cause of this sound may be?

Chapter 4 – Cardiovascular System

Assessment of the carotid arteries involves auscultation followed by palpation. This assessment provides information about cardiac function and the quality of blood flow through the artery.

Unobstructed blood flow is silent, whereas partial obstruction of blood flow (due to ) creates turbulent blood flow, leading to vascular sounds. These sounds are called bruits: blowing/swooshing noises. Following auscultation, if you do not hear bruits, proceed to palpating the carotid pulses. Be aware that complete obstruction of blood flow will also be silent, as there is no blood flowing through the artery.

This assessment is done in the seated position or in the high-fowlers position with the client looking straight ahead. Make sure they do not flex or extend their neck.

Auscultation of Carotid Arteries

1. Cleanse the stethoscope. See Video 4.2.

2. Ask the client to breathe in, breathe out, and then hold their breath.

• This is important because normal tracheal breath sounds can resemble a bruit and limit the nurse’s ability to hear the bruit. Note that some clients are unable to hold their breath for long: tell them to breathe if they feel they need to or if they become lightheaded.

3. With light pressure, place the stethoscope’s bell over the right carotid artery in the middle third of the neck, just medial to the sternomastoid muscle, but closer to the muscle than the trachea. This location is anatomically determined, see Figure 4.2.

• The bell should be used because vascular sounds are low-pitched.
• Usually, listening at one location on each side of the neck is sufficient. Some practitioners listen to three locations on the neck, but this is usually not needed because sound radiates. If you have concerns, you can listen to three locations on each side of the neck: at the base of the neck closer to the origin of the carotid artery; in the middle third of the neck just medial to the sternomastoid muscle, but closer to the muscle than the trachea; and inferior to the angle of the mandible.

4. Repeat the steps two and three on the left carotid artery. 

5. Note the findings

• Normal findings might be documented as: “No carotid bruit present, bilaterally.”
  • NOTE: You may hear the beating of the heart because sound travels.
• Abnormal findings might be documented as: “Carotid artery bruit present” (on left or right side or bilaterally).

Video 4.2: Auscultation of the carotid arteries

Do NOT palpate the carotid artery if you hear a bruit when auscultating the carotid arteries. A bruit can be a critical finding and is suggestive of carotid stenosis and partial obstruction of the artery. It is therefore important to not palpate (compress the artery) when the blood flow is already compromised. You should measure the client’s vital signs (specifically pulse, blood pressure, oxygen saturation, respiration) and continue the cardiac assessment. Then, report your findings to the physician/nurse practitioner.

Palpation of Carotid Arteries

1. First, if you hear a bruit when auscultating the carotid arteries, do not palpate the carotid artery. Only proceed with palpation if you do not hear a bruit. See Video 4.3.

2. Place the pads of your three fingers gently over ONE carotid artery (right or left) in the middle third of the neck, just medial to the sternomastoid muscle. Then, repeat on the opposite artery.

• Do NOT palpate the left and right carotid arteries at the same time, because this can compromise blood flow superior to the location you are palpating (the brain).
• Do NOT place the pads of your finger high on the neck, because this area is the location of the baroreceptors of the carotid sinus. These receptors are medial to the sternomastoid muscle, inferior to the angle of the jaw, and just superior to the thyroid cartilage. They play a role in mediating heart rate and blood pressure, and increased pressure on this area can lead to bradycardia and a drop in blood pressure.

3. Palpate for the following:

• Force (strength of pulsation). Pulse force is recorded using a four-point scale:

• • 3+ Full, bounding
  • 2+ Normal/strong
  • 1+ Weak, diminished, thready
  • 0 Absent/non-palpable

(Adapted from: Vital Sign Measurement Across the Lifespan, 2nd Canadian edition)

• Symmetry (compare force between left and right side).
• Quality (describe the pulsation) in terms of the wave form. The carotid pulsation is described as a quick upstroke (one cursory/brisk outward movement felt against your fingers) and a slow downstroke (a more gradual inward movement away from your fingers).

4. Note the findings

• Normal findings may be documented as: “2+ carotid pulsation equal bilaterally, smooth contour with a quick upstroke and gradual downstroke.”
• Abnormal findings may be documented as (example): “1+ carotid pulsation bilateral with and gradual downstroke” (reduced amplitudes can be common in conditions with low stroke volume, while dicrotic upstrokes can be common with increased peripheral vascular resistance, for example in situations of heart failure).

Figure 4.2: Carotid artery anatomy

Photo by engin akyurt on Unsplash (image was cropped and illustrated upon for the purposes of this chapter)

Video 4.3: Palpation of carotid arteries

Activity: Check Your Understanding

is the narrowing of the carotid artery.

is an abnormal double beat of the carotid artery.

A carotid bruit (pronounced “broo-ee”) is the sound of turbulent blood flow in one or more of your carotid arteries. Turbulent flow means your blood isn’t flowing smoothly through your artery. Instead, blood flow is disorganized and choppy. Your carotid arteries are blood vessels in your neck that supply blood to your brain.

A carotid bruit is a clinical sign that your healthcare provider may notice during a routine physical exam. The sound of a carotid bruit may indicate that your carotid artery is narrowed due to plaque buildup. Sometimes, though, a carotid bruit occurs in people with healthy carotid arteries. Plus, some people with severe carotid artery narrowing don’t have a bruit. So, healthcare providers use this sign as just one piece of a much larger puzzle when deciding if you need further testing or treatment.

What do carotid bruits sound like?

A carotid bruit is a whooshing sound that’s similar to water rushing in a fast-moving river. You can’t hear a carotid bruit on your own. Instead, it’s something that your healthcare provider can hear through a stethoscope.

To check for a carotid bruit, your provider gently presses the end of a stethoscope against several different areas in your neck. You may need to inhale and then hold your breath for a few seconds as your provider listens to your blood flow through the stethoscope.

If your provider hears a carotid bruit, they’ll talk with you about what it might mean and whether you need follow-up testing.

What causes a bruit in the carotid artery?

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. Plaque buildup can also lead to the formation of blood clots. A blood clot may block blood flow in the area where it forms. Or, it may travel through your bloodstream to another artery and block blood flow there.

A carotid bruit may indicate you have plaque buildup in your carotid artery. Plaque buildup in your carotid arteries can lead to carotid artery stenosis. This is a narrowing of your carotid artery.

Your carotid arteries play a major role in supplying oxygen-rich blood to your brain. So, if they fill up with plaque, you face a higher risk of a transient ischemic attack (TIA) or an ischemic stroke. In these conditions, blood flow to your brain is interrupted or blocked.

This is why it’s important to learn if you have carotid artery stenosis, and if so, how severe it is. A carotid bruit can be a warning sign that you have plaque buildup. But it doesn’t show how much plaque is present. So, a carotid bruit alone isn’t enough to diagnose you with carotid artery stenosis. Instead, it’s the first step your provider will use to investigate further.

Although plaque buildup is the most common cause of a carotid bruit, changes in blood vessel anatomy can also cause this vascular sound. For example, people who have fibromuscular dysplasia (FMD) may have a carotid bruit. Your healthcare provider will look at your medical history to help determine the cause of your carotid bruit.

How serious is a carotid bruit?

A carotid bruit may be a sign of a serious problem, but that’s not always the case. It’s sometimes a red flag showing you may have carotid artery stenosis. If your stenosis is severe, you’ll likely need treatment to lower your risk of a TIA or stroke. Your provider will tell you if your condition is serious and if you need treatment.

Can a carotid bruit be normal?

A carotid bruit doesn’t always indicate you have carotid artery stenosis. Some people with a carotid bruit don’t have significant plaque buildup and are otherwise healthy. Some people may have changes in their blood vessel anatomy, which can be normal or due to conditions like FMD. That’s why a carotid bruit is only the first step in diagnosing and treating carotid artery disease.

What happens next if I have a carotid bruit?

The presence of a carotid bruit will alert your provider that something may be wrong. Your provider may order further testing to evaluate the health of your carotid arteries. Such testing usually involves a carotid duplex ultrasound. This is a painless, noninvasive test that checks blood flow in your carotid arteries. It can show if your arteries are narrowed, and if so, how much.

Your provider will likely order such testing if you have a carotid bruit along with one or more risk factors for carotid artery stenosis. These include:

The more risk factors you have, the higher your risk of carotid artery stenosis.

If you need coronary artery bypass grafting (CABG), your provider may first order testing to check your carotid arteries. This is because carotid artery stenosis raises your risk of a stroke during or after some heart surgeries. You may need treatment before your surgery to lower your risk.

What treatments might I need?

Some people with a carotid bruit need treatment to lower their risk of a TIA or stroke. The goal of treatment is to improve blood flow through your carotid arteries.

Medications are often the first line of defense, especially if your carotid arteries aren’t severely narrowed. Depending on your condition, your provider may recommend one or more of the following medications:

• Blood pressure medication.
• Cholesterol-lowering medication.

Lifestyle changes can also play an important role. You can slow down the buildup of plaque in your arteries by taking these steps:

• Avoid smoking and all tobacco products. Tobacco harms your blood vessels and raises your risk for many different cardiovascular diseases. Ask your provider for resources to help you quit.
• Eat a heart-healthy diet. A heart-healthy diet involves limiting your intake of saturated fat, sodium and sugar. Plus, avoid red meat and instead choose lean chicken, turkey or fish.
• Exercise regularly. Start slow, and gradually work up to 150 minutes of moderate-intensity exercise per week. Check with your provider about what’s safe for you before starting a new exercise plan.

If your carotid artery stenosis is more severe, you may need a surgery or procedure. These include:

Not everyone with a carotid bruit has blockages or needs treatment. Talk with your provider to learn more about what your carotid bruit means for you.

A note from Cleveland Clinic

If your healthcare provider mentions a carotid bruit, don’t panic. It doesn’t necessarily mean you’re in danger. It’s simply one sign of many that your provider can use to check the health of your arteries. So, talk with your provider to learn more. Also, ask about your risk factors for atherosclerosis and how you can lower them.