LAB 1: Cardiovascular Assessment
Part A: Measurement of Resting and Exercise Heart Rate
Purpose: The objective of this lab is to teach you how to effectively measure heart rate at rest and during exercise by telemetry (heart rate monitors), palpation (vibration with the fingers), and auscultatory (by ear with the stethoscope) techniques.
SPECIFIC SKILLS INVOLVED:
1. Measurement of heart rate at rest by palpation and auscultation.
2. Measurement of heart rate during exercise by palpation and auscultation.
3. Proper placement and usage of telemetry monitors.
Heart Rate
The rate of the cardiac cycle (heart rate) provides important insight into what is happening in the body at rest and during exercise. A low resting heart rate (HR) (bradycardia < 60 bpm) may indicate a well-conditioned heart that is able to pump large amounts of blood with each beat. Conversely, a high resting heart rate (tachycardia > 100 bpm) may be indicative of a poorly conditioned heart. Resting HR is affected by several factors including body position, diet, consumption of drugs, alcohol, or caffeine, and fatigue.
Generally, males have lower resting HR values than females. For example, males often demonstrate resting HRs between 60 and 70 bpm and females between 70 and 80 bpm. A few reasons for this difference is that females, on average, pump less blood per beat (lower stroke volume), transport less oxygen per volume of blood (because of less hemoglobin), and have a lower total blood volume than do males. Overall, the average population resting HR is approximately 72 bpm. As a person ages, resting heart rate may or may not decrease.
In order to measure true resting heart rate it is important to control several factors:
1. Drug and medication consumption. Many drugs (i.e., caffeine, tobacco, alcohol, prescription medication) directly affect HR. Thus, it is recommended to abstain from consuming these chemicals for at least 12 hours before measuring resting HR.
2. Body position. Skeletal muscle activity is a strong stimulant for increased HR. A resting, supine body position is best during testing. In laboratory conditions, the resting HR is often taken in the sitting position.
3. Dietary status. It takes energy to digest food and HR increases in order to deliver needed blood to metabolically active tissues (i.e., gut). Consequently, it is recommended that subjects fast at least 12 hours before taking a resting HR measurement. This is often not possible when measuring HR in a fitness or clinical setting.
4. Environmental factors. Noise, temperature extremes, and pollution can increase stress. The body’s attempt to overcome stress requires an expenditure of energy which can increase resting HR. Accordingly, it is best to minimize environment extremes as much as possible when measuring resting HR.
During exercise a person’s HR indirectly indicates exercise intensity or exertion levels. Since the heart plays a pivotal role in supplying oxygen and nutrients and removing wastes, the rate of the cardiac cycle is a valid indicator of the demands required of the body.
LAB ACTIVITY
Measurement of resting heart rate:
1. Have the subject rest quietly for at least 5 minutes in the sitting position.
2. The pulse should be measured at rest for 1 minute.
3. Start the stopwatch simultaneously with the pulse beat. Count the first beat as zero. Continue counting for 60 seconds.
In this lab, you will measure HR using three techniques:
1. Telemetry (heart rate monitors): Telemetry involves the transmission of a signal from an adjustable chest harness to an electronic receiver that can be hand held or attached to the wrist. The receiver converts the signal from the chest harness into a quantified HR measurement. Recent research has indicated that telemetry devices can accurately measure both resting and exercise HR. For purposes of this class, you will use heart rate monitors only as accuracy checks for palpation and auscultatory measures. You may not use these monitors when taking your skills tests.
2. Palpation: Feeling a pulse or vibration with the fingers or hand is termed palpation. The pulse, generated by the pulsatile pumping of blood in the arteries, is most easily felt over the radial or carotid arteries.
The pulse may be palpated at the following sites:
brachial artery - on the inside of the upper arm behind the biceps brachial and below the axilla.
carotid artery - in the neck just lateral to the larynx
radial artery - on the anterolateral aspect of the wrist directly in line with the base of the thumb
temporal artery - along the hairline of the head at the temple
Follow these procedures when determining heart rate by palpation:
Use the tip of the middle and index fingers. Do not use your thumb because it has a pulse of its own and may produce an inaccurate count.
When palpating at the carotid site, do not apply heavy pressure to the area. Baroreceptors in the carotid arteries detect this pressure and cause a reflex slowing of the heart rate.
When taking a pulse to measure HR, remember to press lightly with the fingers to avoid occluding (obstructing) the blood flow.
3. Stethoscope: Auscultatory (by ear) HRs are more accurate than palpation methods. In fact, a stethoscope is nearly as accurate in measuring HR as electrocardiography (ECG) equipment. The basic purpose of the stethoscope is to amplify and direct sound waves, thus bringing the ear of the listener closer to the source of the sound.
Follow these procedures when determining heart rate by auscultation:
Insert the ear tips of the stethoscope directly down each ear canal so that the ear tips of the stethoscope point forward. If you fail to position the ear tips properly it will be difficult to hear the heart beat.
Gently tap the diaphragm of the stethoscope to be sure you can pick up sound through the stethoscope.
Position the stethoscope over the third intercostal space of the left sternum.
The diaphragm of the stethoscope should be held firmly against the skin. Placing the stethoscope over clothing increases the chances of hearing interfering sounds from external sources.
Auscultating heart beats at rest with a stethoscope is often more difficult than during exercise since the heart sounds are less pronounced. However, with practice one can become skilled at measuring resting HR with a stethoscope.
Follow these procedures when determining heart rate during exercise:
Same procedures as used for rest except during exercise, HR will be measured for 15 seconds rather than 60 seconds.
Start the stopwatch simultaneously with the pulse beat. Count the first beat as zero.
Continue counting for 15 seconds.
Multiply the 15 sec count by 4 in order to obtain beats per minute (bpm).
For example: a 15 sec count of 35 would give a HR of 140 bpm. A 15 sec count of 50 would give a HR of 200 bpm.
If a 15 sec count of 45 were measured, what is the exercise HR ________ ? Would this heart rate be called bradycardia or tachycardia?
Hints:
Do not allow you subject to talk while you are taking HR.
If palpating the radial or brachial artery, do not allow the subject’s arm or hand to be on the exercise machine.
Support the arm of the subject during measurement so the subject will be as relaxed as possible.
Name: ___________________________ Lab 1 Worksheet
1. Allow your subjects to rest for 5 minutes. Measure RHR at each appropriate site by palpation and auscultation.
2. Have your subject exercise for about 2 minutes at a comfortable pace. Measure exercise heart rate using each method and site.
3. Repeat this procedure with 5 more subjects.
| Name | Resting HR | Exercise HR | Exercise HR |
At the end of this lab you should feel comfortable measuring heart rate by each method and at each appropriate site. You need to practice this many times during this semester.
LAB 1: Cardiovascular Assessment
Part A: Measurement of Resting and Exercise Heart Rate
Purpose: The objective of this lab is to teach you how to effectively measure heart rate at rest and during exercise by telemetry (heart rate monitors), palpation (vibration with the fingers), and auscultatory (by ear with the stethoscope) techniques.
SPECIFIC SKILLS INVOLVED:
1. Measurement of heart rate at rest by palpation and auscultation.
2. Measurement of heart rate during exercise by palpation and auscultation.
3. Proper placement and usage of telemetry monitors.
Heart Rate
The rate of the cardiac cycle (heart rate) provides important insight into what is happening in the body at rest and during exercise. A low resting heart rate (HR) (bradycardia < 60 bpm) may indicate a well-conditioned heart that is able to pump large amounts of blood with each beat. Conversely, a high resting heart rate (tachycardia > 100 bpm) may be indicative of a poorly conditioned heart. Resting HR is affected by several factors including body position, diet, consumption of drugs, alcohol, or caffeine, and fatigue.
Generally, males have lower resting HR values than females. For example, males often demonstrate resting HRs between 60 and 70 bpm and females between 70 and 80 bpm. A few reasons for this difference is that females, on average, pump less blood per beat (lower stroke volume), transport less oxygen per volume of blood (because of less hemoglobin), and have a lower total blood volume than do males. Overall, the average population resting HR is approximately 72 bpm. As a person ages, resting heart rate may or may not decrease.
In order to measure true resting heart rate it is important to control several factors:
1. Drug and medication consumption. Many drugs (i.e., caffeine, tobacco, alcohol, prescription medication) directly affect HR. Thus, it is recommended to abstain from consuming these chemicals for at least 12 hours before measuring resting HR.
2. Body position. Skeletal muscle activity is a strong stimulant for increased HR. A resting, supine body position is best during testing. In laboratory conditions, the resting HR is often taken in the sitting position.
3. Dietary status. It takes energy to digest food and HR increases in order to deliver needed blood to metabolically active tissues (i.e., gut). Consequently, it is recommended that subjects fast at least 12 hours before taking a resting HR measurement. This is often not possible when measuring HR in a fitness or clinical setting.
4. Environmental factors. Noise, temperature extremes, and pollution can increase stress. The body’s attempt to overcome stress requires an expenditure of energy which can increase resting HR. Accordingly, it is best to minimize environment extremes as much as possible when measuring resting HR.
During exercise a person’s HR indirectly indicates exercise intensity or exertion levels. Since the heart plays a pivotal role in supplying oxygen and nutrients and removing wastes, the rate of the cardiac cycle is a valid indicator of the demands required of the body.
LAB ACTIVITY
Measurement of resting heart rate:
1. Have the subject rest quietly for at least 5 minutes in the sitting position.
2. The pulse should be measured at rest for 1 minute.
3. Start the stopwatch simultaneously with the pulse beat. Count the first beat as zero. Continue counting for 60 seconds.
In this lab, you will measure HR using three techniques:
1. Telemetry (heart rate monitors): Telemetry involves the transmission of a signal from an adjustable chest harness to an electronic receiver that can be hand held or attached to the wrist. The receiver converts the signal from the chest harness into a quantified HR measurement. Recent research has indicated that telemetry devices can accurately measure both resting and exercise HR. For purposes of this class, you will use heart rate monitors only as accuracy checks for palpation and auscultatory measures. You may not use these monitors when taking your skills tests.
2. Palpation: Feeling a pulse or vibration with the fingers or hand is termed palpation. The pulse, generated by the pulsatile pumping of blood in the arteries, is most easily felt over the radial or carotid arteries.
The pulse may be palpated at the following sites:
brachial artery - on the inside of the upper arm behind the biceps brachial and below the axilla.
carotid artery - in the neck just lateral to the larynx
radial artery - on the anterolateral aspect of the wrist directly in line with the base of the thumb
temporal artery - along the hairline of the head at the temple
Follow these procedures when determining heart rate by palpation:
Use the tip of the middle and index fingers. Do not use your thumb because it has a pulse of its own and may produce an inaccurate count.
When palpating at the carotid site, do not apply heavy pressure to the area. Baroreceptors in the carotid arteries detect this pressure and cause a reflex slowing of the heart rate.
When taking a pulse to measure HR, remember to press lightly with the fingers to avoid occluding (obstructing) the blood flow.
3. Stethoscope: Auscultatory (by ear) HRs are more accurate than palpation methods. In fact, a stethoscope is nearly as accurate in measuring HR as electrocardiography (ECG) equipment. The basic purpose of the stethoscope is to amplify and direct sound waves, thus bringing the ear of the listener closer to the source of the sound.
Follow these procedures when determining heart rate by auscultation:
Insert the ear tips of the stethoscope directly down each ear canal so that the ear tips of the stethoscope point forward. If you fail to position the ear tips properly it will be difficult to hear the heart beat.
Gently tap the diaphragm of the stethoscope to be sure you can pick up sound through the stethoscope.
Position the stethoscope over the third intercostal space of the left sternum.
The diaphragm of the stethoscope should be held firmly against the skin. Placing the stethoscope over clothing increases the chances of hearing interfering sounds from external sources.
Auscultating heart beats at rest with a stethoscope is often more difficult than during exercise since the heart sounds are less pronounced. However, with practice one can become skilled at measuring resting HR with a stethoscope.
Follow these procedures when determining heart rate during exercise:
Same procedures as used for rest except during exercise, HR will be measured for 15 seconds rather than 60 seconds.
Start the stopwatch simultaneously with the pulse beat. Count the first beat as zero.
Continue counting for 15 seconds.
Multiply the 15 sec count by 4 in order to obtain beats per minute (bpm).
For example: a 15 sec count of 35 would give a HR of 140 bpm. A 15 sec count of 50 would give a HR of 200 bpm.
If a 15 sec count of 45 were measured, what is the exercise HR ________ ? Would this heart rate be called bradycardia or tachycardia?
Hints:
Do not allow you subject to talk while you are taking HR.
If palpating the radial or brachial artery, do not allow the subject’s arm or hand to be on the exercise machine.
Support the arm of the subject during measurement so the subject will be as relaxed as possible.
Name: ___________________________ Lab 1 Worksheet
1. Allow your subjects to rest for 5 minutes. Measure RHR at each appropriate site by palpation and auscultation.
2. Have your subject exercise for about 2 minutes at a comfortable pace. Measure exercise heart rate using each method and site.
3. Repeat this procedure with 5 more subjects.
| Name | Resting HR | Exercise HR | Exercise HR |
At the end of this lab you should feel comfortable measuring heart rate by each method and at each appropriate site. You need to practice this many times during this semester.