Interactive Guide to Physical Examination
Cardiovascular

The Carotid Impulse

The characteristics of the carotid wave form are determined by resistance to blood flow in the arterial tree, distensibility of the arterial walls, and the magnitude of the left ventricular impulse. Evaluation of the character of the impulse sheds light on the integrity of the vascular system as well as intracardiac structures.

Auscultation:

In some instances auscultating over the carotid for a bruit may be helpful. Remember that the carotid bulb is up near the angle of the jaw. Listen here while the patient holds his breath, with the bell or diaphragm of the stethoscope pressed lightly to the skin.

View interactive module Click on the interactive icon for a review of carotid bruit.

Palpation:

To assess patency, compare the right carotid artery to the left. Grade the strength of the impulse using a scale of zero to 4+. Impairment of one or both sides can be seen in atherosclerotic narrowing, with thrombus, aortic arch disease, dissecting aortic aneurysm or impediment from a cervical rib.

The carotid pulse also provides information about left ventricular function and valvular disease. Note the character of the upstroke, dicrotic notch and downstroke. The normal carotid upstroke is brisk, with a rapid rise leading to the pressure peak, and then falls rapidly in the latter part of systole. In contrast, a hyperkinetic pulse is characterized by a more rapid upstroke and similarly a more rapid downstroke than normal. A dampened or hypokinetic pulse is characterized as having low amplitude. It may also be slow-rising and late peaking, pulsus parvus et tardus.

The differences in these impulses are illustrated below.


View video Click on the video icon to review physical exam techniques for evaluation of the carotid impulse.