15.5: Heart Rate
By the end of this section, you will be able to:
- Describe anatomical locations for obtaining the pulse
- Describe the different pulse characteristics
- Identify factors affecting pulse rates
Palpating the pulse is another aspect of obtaining vital signs. Blood flow, which is caused by the beating heart, can be detected where arteries occur close to the surface of the skin. The pulse, along with breathing, is one of the first vital signs assessed in emergency situations because it demonstrates cardiac functioning. When monitored routinely, the pulse provides a baseline for the perfusion of the body and alerts the practitioner to any changes in this baseline. Palpation of the peripheral pulses, those arteries farthest away from the heart, provide the nurse with a wealth of information, such as the heart rate, rhythm, and strength.
See the competency checklist for Vital Signs: Pulse and Respiratory Rate. You can find the checklists on the Student resources tab of your book page on openstax.org.
Pulse Locations
Pulse locations are anatomical places on the body where the pulse should be readily palpable because of the artery’s proximity to the surface of the skin (Figure 15.23). The most frequent locations for detecting pulses are over the radial, temporal, and carotid arteries.
The most common pulse location is the radial pulse . This pulse is found on the distal lateral forearm. The radial pulse is the preferred site to obtain a pulse for routine vital signs.
The temporal pulse site is located on either side of the forehead. The carotid pulse is located on the anterior neck on both sides of the trachea. This is the location of large arteries that branch off the aorta and are the main blood supply to the brain. When a nurse must check the carotid pulse, only one side should be assessed at a time to not restrict blood flow to the brain. This pulse location, due to its size, is often checked in emergency situations to verify the presence or absence of a pulse.
The apical pulse is auscultated directly using a stethoscope. It is located at the fifth intercostal space, midclavicular line on the anterior chest wall. The apical pulse is counted for one full minute when obtaining routine vital signs. Certain populations need the apical pulse auscultated rather than palpating the peripheral pulse. For example, the heart rate should be auscultated in patients receiving digoxin , a medication that affects the heart rate and contraction, and those with an irregular rate or rhythm. As a nurse, if the peripheral pulse requires further investigation, for example, too weak to be felt or too fast to be counted, listening to the apical pulse is a good way to validate results.
The brachial pulse is found in the inner antecubital space and is used when obtaining blood pressure . The stethoscope is placed over this artery to listen to blood flow in the arteries. In infants, the brachial pulse is felt in the inner upper arm and is the preferred upper extremity peripheral pulse site in this age group. It is used in emergency situations to determine the presence or absence of a pulse in infants since the carotid pulse is difficult to quickly locate.
The femoral pulse is found in the groin. The femoral artery is a large artery that provides blood flow to the lower extremities. This femoral pulse is the preferred lower extremity pulse site in infants.
There are several other pulse locations in the lower extremities. One such pulse site is the popliteal pulse , found behind the knee. Other lower extremity pulses are the posterior tibial pulse , located behind the inner ankle, and the dorsalis pedis pulse , commonly called the pedal pulse, which is located on the dorsal aspect of the foot. The dorsalis pedis pulse is the preferred lower extremity peripheral pulse site in adults and children.
When obtaining routine vital signs on an adult, the nurse should assess the radial pulse . However, sometimes this location might not be the optimal pulse location. The radial pulse is not always available to be assessed. For example, the patient may have an arterial line inserted or a cast or bandage may be covering the site. Amputation may also have occurred. In cases where the radial pulse is inaccessible, the nurse should auscultate to obtain the apical pulse. The apical pulse should be listened to for a full minute to determine the heart rate, and the brachial and femoral pulses should be palpated to assess peripheral perfusion. Palpation of the pulse is a direct representation of blood volume and flow. A weak, thready pulse may be due to reduced cardiac blood flow such as with dehydration or heart disease.
Pulse Characteristics
When obtaining the pulse, or heart rate, the nurse is also assessing characteristics such as rhythm, depth, and quality. Characteristics of the pulse provide information about the predictability and efficiency of the heart and the quality of the blood vessels. For instance, the heart may be strong and healthy, but if the blood vessels are occluded, the pulse will feel weak or even absent. The nurse needs to note the rhythm, depth, and quality of the pulse to ensure the health of the cardiovascular system.
Rate
The pulse rate, measured in beats per minute, is obtained to ensure the heart is beating adequately. The normal range for an adult pulse rate is 60 to 100 beats per minute. Because the range is wide (Table 15.7), the nurse should also be familiar with the patient’s trends, if available. In general, pulse rates for females are slightly higher than for males, and infants and children have a pulse rate that is higher than the adult range.
| Age | Heart Rate (beats per minute) |
|---|---|
| Birth to 4 weeks | 130 to 190 |
| 1 to 3 months | 125 to 185 |
| 3 to 6 months | 110 to 165 |
| 6 to 12 months | 105 to 160 |
| 1 to 3 years | 100 to 155 |
| 3 to 5 years | 70 to 120 |
| 5 to 8 years | 60 to 110 |
| 8 to 12 years | 55 to 100 |
| Adolescents | 50 to 100 |
| Adults | 60 to 100 |
Adolescents and athletes tend to have a slower resting heart rate, to rates as slow as 40 to 50 beats per minute. This is because the strength and force of their heart contraction is greater than for most of the population, which produces a greater stroke volume. The stroke volume (SV) represents the amount of blood pumped by the left ventricle with each contraction. Heart rate and stroke volume determine cardiac output. The cardiac output is the total amount of blood ejected by the heart into circulation in one minute, measured in liters. The formula for cardiac output is CO (cardiac output) = SV (stroke volume) × HR (heart rate). If the stroke volume is significantly increased, the heart rate can decrease as the same cardiac output is achieved. Stroke volume and cardiac output are inversely related.
A pulse rate slower than 60 beats per minute is known as bradycardia , whereas a pulse rate faster than 100 beats per minute is referred to as tachycardia . If the heart fails to contract and produce a pulse, it is known as asystole .
Rhythm
When the pulse is being assessed, the nurse should also take note of the regularity of the pulse, also known as its rhythm. A regular rhythm is normal with predictable beats, whereas an irregular rhythm may indicate the presence of cardiac anomalies such as atrial fibrillation .
An abnormal heart rate and rhythm is known as arrhythmia (also called dysrhythmia ). Bradycardia, tachycardia, atrial fibrillation, and ventricular fibrillation are some of the most common arrhythmias. Fibrillation occurs when a chamber of the heart, either the atrium or ventricle, is unable to contract. Instead of contracting completely, it quivers. In ventricular fibrillation, no pulse or contraction of the heart is present, resulting in decreased stroke volume and decreased cardiac output, which requires resuscitation.
Volume
The strength of the pulse provides qualitative information on the volume of circulating blood volume . A healthy pulse is a strong pulse. However, a very strong pulse is described as bounding . Bounding pulses may occur in cases of right-sided heart failure because blood becomes backed up in the peripheral circulation. In contrast to very strong pulses, weak pulse s are caused by a variety of conditions, including loss of blood volume, peripheral vascular disease , and left-sided heart failure.
Factors Affecting Pulse Rates
Normal and healthy fluctuations can occur, and they affect pulse rate . Exercise, particularly aerobics, increases pulse rate. Sleep, conversely, decreases the pulse. Emotions also affect the heart rate. Intense fear and anxiety increase the pulse rate, while relaxation lowers it.
Nurse:
Cielita, RN
Clinical setting:
Pediatric intensive care unit
Years in practice:
15
Facility location:
Florida
I was once caring for a young boy who suffered cardiac arrest, was resuscitated, and was admitted to the pediatric intensive care unit in a coma. The boy’s father was so distraught, and the mother encouraged him to go to a walk-in clinic to get some medications for his anxiety. He went to the clinic, but when they checked his heart rate, they ordered an electrocardiogram (ECG) which came back irregular. An ambulance was called to bring him over to the nearest emergency department. At the emergency department, his heart rate was extremely elevated, but once he heard his son was improving, his heart rate normalized. After multiple cardiac tests, no other cause was determined for this brief abnormality besides his emotions.
Pulse rate abnormalities also occur because of physical conditions. Conditions that increase metabolism, such as a fever and hyperthyroidism, will also increase the pulse rate. A lack of oxygen will also increase pulse rate. A lack of oxygen can occur as a result of a variety of pulmonary complications. Without enough oxygen, body tissues are unable to be perfused, or receive the oxygen needed to function. The body then feeds this information back to the brain, which signals the heart to then attempt to resolve by increasing the heart rate. When circulating blood volume is decreased, heart rate will also increase to compensate for the lack of perfusion.
Cardiac abnormalities will also affect pulse rate. Structural problems with the heart may lead to an increased pulse rate since the efficacy of the heart contraction is generally weakened. Heart failure, which may result from structural cardiac anomalies or lifestyle, may also increase heart rate. The heart is unable to contract effectively, which, in turn, causes the heart rate to compensate to aid in maintaining cardiac output. Electrical abnormalities in the heart will lead to a host of cardiac arrythmias, which affect not only pulse rate but also the rhythm.
Refer back to Unfolding Case Study #3: Part 1 to review the patient data.
| Assessment |
1200:
Neurological: Alert and oriented ×4, GCS 15 HEENT (head, eyes, ears, nose, and throat): Within normal limits Respiratory: Accessory muscle use, tripod positioning, crackles in lung bases, fingernail clubbing noted Cardiovascular: Weak, thready pulse. 1+ pitting edema of bilateral lower extremities Abdominal: Within normal limits Musculoskeletal: 4/5 muscle strength of right arm, all other extremities 5/5 Integumentary: Skin pale but dry and intact |
| Provider’s Orders |
1215:
Continuous ECG monitoring Start home medications Vital signs Q4 hours Admit to medical-surgical unit for observation |