The pulse rhythm, rate, force, and equality are assessed when palpating pulses.
The normal pulse rhythm is regular, meaning that the frequency of the pulsation felt by your fingers follows an even tempo with equal intervals between pulsations. If you compare this to music, it involves a constant beat that does not speed up or slow down, but stays at the same tempo. Thus, the interval between pulsations is the same. However, sinus arrhythmia is a common condition in children, adolescents, and young adults. Sinus arrhythmia involves an irregular pulse rhythm in which the pulse rate varies with the respiratory cycle: the heart rate increases at inspiration and decreases back to normal upon expiration. The underlying physiology of sinus arrhythmia is that the heart rate increases to compensate for the decreased stroke volume from the heart’s left side upon inspiration.
Points to Consider
If a pulse has an irregular rhythm, it is important to determine whether it is regularly irregular (e.g., three regular beats and one missed and this is repeated) or if it is irregularly irregular (e.g., there is no rhythm to the irregularity). Irregularly irregular pulse rhythm is highly specific to atrial fibrillation. Atrial fibrillation is an arrhythmia whereby the atria quiver. This condition can have many consequences including decreased stroke volume and cardiac output, blood clots, stroke, and heart failure.
The pulse rate is counted by starting at one, which correlates with the first beat felt by your fingers. Count for thirty seconds if the rhythm is regular (even tempo) and multiply by two to report in beats per minute. Count for one minute if the rhythm is irregular. In children, pulse is counted for one minute considering that irregularities in rhythm are common.
The pulse force is the strength of the pulsation felt when palpating the pulse. For example, when you feel a client’s pulse against your fingers, is it gentle? Can you barely feel it? Alternatively, is the pulsation very forceful and bounding into your fingertips? The force is important to assess because it reflects the volume of blood, the heart’s functioning and cardiac output, and the arteries’ elastic properties. Remember, stroke volume refers to the volume of blood pumped with each contraction of the heart (i.e., each heart beat). Thus, pulse force provides an idea of how hard the heart has to work to pump blood out of the heart and through the circulatory system.
Pulse force is recorded using a four-point scale:
- 3+ Full, bounding
- 2+ Normal/strong
- 1+ Weak, diminished, thready
- 0 Absent/non-palpable
Practice on many people to become skilled in measuring pulse force. While learning, it is helpful to assess pulse force along with an expert because there is a subjective element to the scale. A 1+ force (weak and thready) may reflect a decreased stroke volume and can be associated with conditions such as heart failure, heat exhaustion, or hemorrhagic shock, among other conditions. A 3+ force (full and bounding) may reflect an increased stroke volume and can be associated with exercise and stress, as well as abnormal health states including fluid overload and high blood pressure.
Pulse equality refers to whether the pulse force is comparable on both sides of the body. For example, palpate the radial pulse on the right and left wrist at the same time and compare whether the pulse force is equal. Pulse equality is assessed because it provides data about conditions such as arterial obstructions and aortic coarctation. However, the carotid pulses should never be palpated at the same time as this can decrease and/or compromise cerebral blood flow.