The pulse is the rhythmic expansion and recoil of an artery caused by the wave of blood ejected from the heart with each beat. The brachial pulse, located in the arm, is directly linked to the large brachial artery, making it an accessible and reliable site for assessing heart rate and circulatory function in clinical practice.
The Artery and Its Location
The brachial artery is the principal blood vessel supplying oxygenated blood to the arm and forearm. It begins in the shoulder region as a continuation of the axillary artery, after crossing the lower border of the teres major muscle. It travels down the inner (medial) side of the upper arm.
The artery continues until it reaches the antecubital fossa, the inner bend of the elbow. Here, the artery lies relatively close to the surface, making its pulse detectable through the skin. It is typically palpated just above the crease of the elbow, medial to the tendon of the biceps muscle, before it divides into the radial and ulnar arteries.
How to Locate and Measure the Brachial Pulse
To locate the brachial pulse, the arm should be slightly extended and relaxed, with the inner elbow facing upward. The correct location for palpation is in the antecubital fossa, just above the elbow crease. The pulse is usually found in a slight indent between the bicep and other muscles.
Use the pads of two or three fingers—the index and middle fingers are most common—to search for the pulse; the thumb should be avoided as it has its own detectable pulse. Apply gentle but firm pressure in the area just above the elbow crease. Because the brachial artery is often deeper than other surface arteries, such as the radial pulse at the wrist, a slightly firmer press may be necessary to feel the rhythmic beat.
Once the pulse is located, the heart rate can be determined by counting the number of beats felt over a specific period. For a quick estimate, count the beats for 15 seconds and then multiply that number by four to calculate the rate in beats per minute. For the most accurate measurement, if the pulse feels irregular, the beats should be counted for a full 60 seconds.
Essential Role in Healthcare Assessment
The brachial pulse is used in clinical assessment due to its reliable location and size. Its most common application is in the manual measurement of blood pressure using a sphygmomanometer, or blood pressure cuff. The cuff is placed on the upper arm, and the stethoscope is positioned over the brachial artery in the antecubital fossa to listen for the sounds of blood flow.
During this auscultatory method, the artery is temporarily compressed by the cuff, and the first sound heard as the pressure is released corresponds to the systolic blood pressure. The brachial artery’s accessibility and consistent anatomy make it the standard site for obtaining this vital sign. This pulse point is also important in the assessment of infants and young children.
The brachial pulse is the preferred site for checking circulation in infants, especially during emergency situations like CPR. In babies, other major pulse points, such as the carotid artery in the neck, are smaller and more difficult to locate quickly and reliably. The brachial artery is relatively large and lies close to the surface on the inner upper arm of an infant, offering a more dependable location to assess circulatory status. A rapid check of this pulse helps medical professionals and first responders determine the need for immediate intervention.