Pulse
In
medicine, a person's
pulse is the throbbing of their
arteries as an effect of the
heart beat. It can be felt at the
neck, at the
wrist and other places.
Pressure waves move through the blood vessels, which are pliable; it is not caused by the forward movement of the
blood. When the heart contracts, blood is ejected into the
aorta and the aorta stretches. At this point the wave of distention (
pulse wave) is most pronounced, but relatively slow-moving (3 to 5 m/s). As it travels towards the peripheral blood vessels, it gradually diminishes and becomes faster. In the large arterial branches, its velocity is 7 to 10 m/s; in the small arteries, it is 15 to 35 m/s. The pressure pulse is 15 or more times more rapidly transmitted than the
blood flow.The pulse results The term
pulse is also used, although incorrectly, to denote the frequency of the heart beat, usually measured in
beats per minute. In most people, the pulse is an accurate measure of
heart rate. Under certain circumstances, including
arrhythmias, some of the heart beats are ineffective and the aorta is not stretched enough to create a palpable pressure wave. The pulse is irregular and the heart rate can be (much) higher than the pulse rate. In this case, the heart rate should be determined by
auscultation of the heart apex, in which case it is not the pulse. The
pulse deficit (difference between heart beats and pulsations at the periphery) should be determined by simultaneous
palpation at the
radial artery and auscultation at the heart apex.
A normal pulse rate for a
healthy adult, while resting, can range from 60 to 100
beats per minute (
BPM). During sleep, this can drop to as low as 40 BPM; during strenuous
exercise, it can rise as high as 200–220 BPM. Generally, pulse rates are higher in younger persons. A resting heart rate for an infant is as high as or higher than an adult's pulse rate during strenuous exercise.
Besides its rate, the pulse has other qualities which reflect the state of the
cardiovascular system, such as its rhythm, fullness and the shape of the pulse wave. Certain diseases cause characteristic changes in these qualities. The absence of a pulse at the temple of the skull can be a sign of
giant cell arteritis; absent or decreased pulses in the limbs may indicate
peripheral artery occlusive disease.
Pulses are manually
palpated with fingers or thumb. When palpating the
carotid artery, the
femoral artery or the
brachial artery, the thumb may be used. However, the thumb has its own pulse which can interfere with detecting the patient's pulse at other points, where two or three fingers should be used. Fingers or thumb must be placed near an artery and pressed gently against a firm structure, usually a
bone, in order to feel the pulse.
 |
Checking the radial pulse. |
*
radial pulse - located on the thumb side of the wrist (
radial artery)
*
ulnar pulse - located on the little finger side of the wrist (
ulnar artery)
*
carotid pulse - located in the neck (
carotid artery). The carotid artery should be palpated gently. Stimulating its
baroreceptors with vigorous palpitation can provoke severe
bradycardia or even stop the heart in some sensitive persons. Also, a person's two carotid arteries should not be palpated at the same time, to avoid a risk of
fainting or brain
ischemia.
*
brachial pulse - located between the biceps and triceps, on the
medial side of the elbow cavity; frequently used in place of carotid pulse in infants (
brachial artery)
*
femoral pulse - located in the thigh (
femoral artery)
*
popliteal pulse - located behind the
knee in the
popliteal fossa, found by holding the bent knee. The patient bends the knee at approximately 120°, and the physician holds it in both hands to find the
popliteal artery in the pit behind the knee.
*
dorsalis pedis pulse - located on top of the foot (
dorsalis pedis artery)
*
tibialis posterior pulse - located in the back of the ankle behind the
medial malleolus (
posterior tibial artery).
*
temporal pulse - located on the
temple directly in front of the ear (
temporal artery)
The ease of palpability of a pulse is dictated by the patient's
blood pressure. If his or her
systolic blood pressure is below 90 mmHg, the radial pulse will not be palpable. Below 80 mmHg, the brachial pulse will not be palpable. Below 60 mmHg, the carotid pulse will not be palpable. Since systolic blood pressure rarely drops that low, the lack of a carotid pulse usually indicates death. It is not unheard of, however, for patients with certain injuries, illnesses or other medical problems to be conscious and aware with no palpable pulse.
Attributes of Pulse measurement.
Include the rate or frequency of the pulse and its rhythm including its regularity and quality expressed as volume or strength
*
Haemodynamics*
Heart*
Heart rate*
Physical examination*
Pulsus bisferiens*
Pulsus paradoxus (paradoxical pulse)
*
Pulsus tardus et parvus
