When performing a cardiovascular assessment, auscultation and palpation are used to examine the character of the vasculature. Bruits may be felt over arteries and sometimes thrills are palpated. Why are these significant?
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. The diaphragm of the stethoscope is used first to better hear the higher frequency of arterial bruits. In cases where the patient has high-grade stenosis, the frequency is lower (and sometimes absent) which can be better heard with the bell (Bickley, et al., 2021). A bruit may be heard in two phases.
When assessing for carotid bruits, ask the patient to hold their breath for no more than 10 seconds while auscultating to better distinguish bruits from sounds transmitted from the trachea. Other areas to assess for bruits includes the abdominal aorta, as well as the renal and iliac arteries.
A thrill is a vibration felt upon palpation of a blood vessel or over the precordium. The examiner may perceive a systolic and diastolic component to the vibration (Bickley et al., 2021). The presence of a thrill suggests stenosis, either of the underlying vessel or it may be transmitted from another source. The grading of systolic murmurs is influenced by the presence of a palpable thrill.
- A bruit is the auscultated equivalent of the thrill and has the same significance.
- A thrill felt at the carotid artery may signify aortic stenosis, as the vibration is transmitted through the tissue from the second intercostal space. (Bickley et al., 2021).
- A thrill and a bruit at the site of an arteriovenous (AV) fistula, commonly used for hemodialysis, is a normal finding (Beathard, 2021).
Beathard, G.A. (2022, January 3). Physical examination of the arteriovenous graft. UpToDate. https://www.uptodate.com/contents/physical-examination-of-the-arteriovenous-graft
Bickley, L. S., Szilagyi, P. G., Hoffman, R. M., & Soriano, R. P. (2021). Bate’s Guide to Physical Examination and History Taking (13th ed.). Wolters Kluwer Health: Philadelphia.