Taking Your Pulse

Long before the tools to listen to and measure heart rate were available, medical professionals were paying  attention to the beat of the heart. In fact, the way the heart beats (fast  or slow, regular or irregular) is so important that it is one of the things doctors almost always check during medical exams. Basically, there are two methods of measuring heart rate: manually (with  the  fingers), which is commonly called palpation or taking  your  pulse,  or mechanically (with  a device such as a heart rate monitor). Manual palpation involves feeling your pulse by applying pressure near an artery. This  is different from  measuring the  electrical signal of the heart, which is what a heart rate monitor does. Manual palpation measures the biomechanical heart signal, whereas heart rate monitors measure the electrical heart signal. Although you might expect the heart rate and pulse rate to be identical, this is not always true. Heart rate refers to the electrical impulses that cause the heart to beat; pulse, or pulse rate, refers to the movement of blood through the arteries. Because many things can interfere with  blood flow at or before the  site  of palpation, it stands to reason that the  greater the distance between the  heart and  the  palpation site,  the  greater the  chance of error. Human error (e.g., miscounting the  pulse) is also  common when  measuring pulse. In fact,  in one study, subjects monitoring their pulse by palpation got readings that averaged 17 beats per minute (bpm) lower  than the  readings taken at the  same time with a heart rate monitor.

Note: Both pulse and heart rate can differ greatly among two people of the same age. This is the  result of a combination of genetic and  fitness factors.

Although 16 possible palpation sites exist,  the  most common places to monitor pulse are at the carotid artery (at the neck) and at the radial artery (at the wrist) (see figure 2.1).

• At the carotid artery: Have students place two fingers lightly on the side of the neck just below the chin. Note: When students are taking a carotid pulse, warn them against exerting too much pressure against the artery. Too much pressure at that point can stimulate the vagus nerve, which may cause them to faint.
• At the radial artery on the wrist: Have students place two fingers lightly on the inside of either wrist below the  thumb.

Figure 2.1    Taking pulse using (a) the carotid artery and (b) the radial artery.