HEART RATE
BLOOD PRESSURE
DOUBLE PRODUCT
Fall  2005

200 Points

     The cardiovascular system is controlled at several levels.  The most basic level of control includes simple reflexes.  The most complex control may occur during exercise where conscious thought, motor cortex, joint reflexes, and local muscle metabolites contribute to the heart rate and blood pressure response.   The cardiovascular response to exercise varies with different types of exercise.   This lab explores the basic heart rate, blood pressure, and double product response to

ll of these conditions can be applied to scenarios in the clinical setting.

    This lab also explores the variation in normal 24 hour blood pressure. Because medications can modify the cardiovascular response to exercise, the concept of drug effects on the cardiovascular system is introduced.

 

Click here to download the lab write-up.

Click here to download the data form.
Turn this data form in to Dr. Wallace as soon as you collect the data.

GETTING READY FOR THIS LAB:

    The three most common cardiovascular measurements in the clinical setting are 1) heart rate, 2) blood pressure, and 3) double product.  Other, more advanced measurements of cardiac performance include ejection fraction and wall motion.   The electrocardiogram is also used to evaluate heart rate, heart rhythm, heart axis, dysrhythmias, and injury/ischemia/infarct.

Heart Rate:

    Heart rate is the frequency of contraction of the myocardium, for one minute.    Heart rate is one method in which the myocardium regulates cardiac output (the amount of blood the heart pumps out to the vasculature in one minute).

    Use the polar monitors to measure heart rate via the following techniques:

  1. Remove hair from area, if needed.
  2. Clean the site with alcohol to remove body oils.
  3. Abrade the skin to remove the first few layers of skin.
  4. Apply electrodes.

Blood Pressure

    Blood pressure is defined as the lateral pressure exerted by the blood against the walls of the enclosing blood vessel.   In a strict sense of the definition, then, blood pressure represents the potential (or stored) energy.   In man, blood pressure is measured most often indirectly via auscultation.    A sphygmomanometer and stethoscope are used.   The sphygmomanometer consists of a mercury manometer and pneumatic cuff.    The cuff is composed of a rubber bladder containing two rubber tubes; one tube is connected to a manometer (either mercury of anaeroid) while the other tube leads to an inflating bulb which has a needle valve.

A method for taking blood pressure is as follows:

  1. Either arm may be used, however, to standardize measurements, the same arm should be measured.   If at all possible, keep the upper arm at heart level.
  2. Fasten the cuff snugly around the upper arm so that the center of the inflatable bladder is on the medial side of the arm.
  3. Palpate the brachial artery.
  4. Place the diaphragm of the stethoscope on the brachial artery.
  5. Rapidly inflate the cuff above systolic pressure up to approximately 200 mmHg.
  6. Slightly open the valve to allow the mercury to fall slowly (at a rate of 3 mm Hg/sec.).
  7. Listen and record the pressures as the nearest even number to the appropriate sounds.
    1. Onset of sound - systolic pressure
    2. Murmur
    3. Tap
    4. Muffle - true diastolic
    5. Absence- clinical diastolic
Click here to hear the blood pressure sounds

    If you record systolic and clinical diastolic pressures, the values should be written:

120/80 mmHg

    If you record the three pressures of systolic, true diastolic, and clinical diastolic, the values should be written:

120/80-70 mmHg

    If you record all three pressures, but the true and clinical pressures are the same, the values should be written:

120/80-80 mmHg

    Usually, true and clinical diastolic pressures are within 10 mmHg.  However, during exercise, the clinical diastolic can go as low as zero.  It is not uncommon to see the clinical diastolic pressure go down to zero in young women and children.  Therefore, taking all three pressures are a good practice to get into.

Double Product

    Double product (Rate Pressure Product) is the product of heart rate and systolic blood pressure.  Double product reflects the work of the heart and correlates well with myocardial oxygen consumption (mVO2).    The actual number that results from the multiplication of heart rate and blood pressure is high.    For example, a heart rate of 100 /min and a blood pressure of 120/80 mmHg will result in a double product of 12000.    To make the number more manageable, the value is divided by 100.    Thus, the double product of 12000 will be reported as 120.

Double Product = [Heart Rate x Systolic Blood Pressure]/100

 

Heart Rate Variability

 

LABORATORY PROCEDURES:

      These procedures can be spread out over two lab periods.    A suggested schedule would be to do Sections I through V during the first session and Section VI during the second.    Use the same subject so that comparisons between conditions can be made easily.    Use the same technicians to measure blood pressure to assure consistency in measurement.  Groups should consist of

  1. Group Leader
  2. Subject
  3. Blood Pressure Technician
  4. Heart rate Technician
  5. Recorder and timer

Some of these jobs can be combined if the groups need to be smaller.

I. BASELINE
  1. Determine a heart rate, blood pressure, and double product of your subject in a quiet, resting seated position.   Make five determinations spaced at one minute intervals.   These values will be averaged and used as control or baseline values for subsequent comparisons.
  2. Repeat the same measurements in the supine position.
II. POSITIONS

A. Passive Tilt - using the tilt table   

 
  1. Subject assumes a supine position on the tilt table.
  2. Allow 3-5 minutes of rest to achieve baseline measures.
  3. Record and measure the heart rate and blood pressure each minute during the rest period.  Use the average as the baseline.
  4. Inflate the cuff to 150 mmHg.
  5. Move the tilt table to 80o head up position.   Make sure the subject does not lock his/her knees.
  6. Measure and record an immediate heart rate and blood pressure.
  7. Measure and record heart rate and blood pressure, each minute, for 5 minutes, thereafter.    Terminate test early if subject feels light-headed or if systolic blood pressure drops >30 mmHg.
  8. Repeat the same procedures, using a 70o head down tilt.   Discontinue if systolic blood pressure increases >30 mmHg.

Click here for a recording form.

QUESTIONS

Indicate references, including page numbers.

1. Graph the heart rate and blood pressure (both systolic and diastolic) changes for the passive tilting. (5 pt.) (Hint: Draw the graph so that it answers the following questions)

2. How do the heart rate and blood pressure adjustments to passive tilt differ for head up vs head down? (5 pt.)

3. Explain the mechanisms for the adjustment of systolic blood pressure and heart rate when tilting from the supine to the standing position. Use a diagram if it helps (5 pts.)

B. Active Posture Changes or Orthostatic Challenges

Supine to Standing

    1. Hook this subject up to a single channel ECG (for the supine to standing procedure)
    2. Have subject lay supine on a lab table.
    3. Allow 3-5 minutes of rest to achieve baseline measures.
    4. Record and measure the heart rate and blood pressure each minute during the rest period.
    5. Inflate the cuff to 150 mmHg.

6. Turn the ECG to record continuously from standing through one minute of standing

7. Have the subject stand-up beside the table.

8. Measure and record an immediate blood pressure.

9. Measure and record heart rate and blood pressure, each minute, for a total of 5 minutes, thereafter.    Terminate test early if subject feels light-headed or if systolic blood pressure drops >30 mmHg. Have the subject move his/her legs.

Standing to an Inverted Position (Head or Hand Stand)
  1. Have subject do a supported head stand.
  2. Measure and record an immediate heart rate (polar monitor) and blood pressure (cuff can not be at heart level).
  3. Measure and record heart rate and blood pressure, each minute, for a total of 5 minutes, thereafter.    Terminate test early if the subject cannot maintain the posture.
  

Click here for a recording form.

QUESTIONS.

4. Graph the heart rate and blood pressure (both systolic and diastolic) changes for the active postural changes. (5 pt.) (Hint: Draw the graph so that it answers the following questions)

5. Were the cardiovascular adjustments to standing normal?   Describe a normal response? (5 pts).

6. Graph the heart rate and blood pressure (both systolic and diastolic) changes for the passive tilting vs active postural changes on two separate graphs. (10 pts) (Hint: Draw the graph so that it answers the following questions)

a. Hand stand vs Head down tilt

b. Supine to standing vs. Head up tilt

7. How does the cardiovascular response to passive tilt differ from the active postural changes?    Explain what might be different between the two mechanisms. (10 points)

8. What is autonomic neuropathy? How do the cardiovascular adjustments to posture differ in autonomic neuropathy?    Explain the mechanism. (10 pts)

 

III. DEEP BREATHING (Must be done with bipolar ECG hook-up)

    While the subject is in a sitting posture, have him/her alternate 6 seconds of deep inhalation followed by 6 seconds of deep exhalation, for one minute.  

  1. Record the heart rate for the entire minute.
  2. Mark each inhalation and exhalation on the ECG paper.
  3. Measure the heart rate for each inhalation and exhalation.

QUESTIONS.

9. Compare the heart rates of inspiration to the heart rates of expiration (one minute deep breathing exercise).   Do the heart rates differ?    If so, how?    What are the possible mechanisms? (10 pts)

IV. CAFFEINE (Use a different subject, preferably one who does not use caffeine regularly)
  1. Measure and record an initial heart rate and blood pressure, each minute, for a total of 5 minutes.
  2. Have subject drink a cup of coffee or (caffeinated) cola.
  3. Measure and record pulse rate and blood pressure every 15 minutes, for the next 75 minutes.   Make sure the subject is measured, each time, in the same position used for baseline.

Click here for a recording form.

QUESTIONS.

10. Graph the heart rate and blood pressure changes to caffeine. (5 pt.) (Hint: Draw the graph so that it answers the following questions)

11. What does caffeine do to heart rate and blood pressure?    What are the mechanisms? (10 pts.)

12. Does caffeine modify the cardiovascular response to exercise? If so, how? (5 pts)

V. ENVIRONMENT

Exposure to Cold
  1. Randomize the order of heat and cold conditions.
  2. Measure heart rate and blood pressure, each minute, for a total of 5 minutes of sitting rest.
  3. Have subject submerge the forearm of the opposite arm in an ice bath.
  4. Measure heart rate and blood pressure, each minute, for a total of 5 minutes of cold or until diastolic blood pressure >110 mmHg or increases >20 above rest.
Exposure to Heat
  1. Dry the arm and let it return to room temperature.
  2. Allow heart rate and blood pressure to return to baseline.
  3. Expose the same arm to heat lamp.
  4. Measure heart rate and blood pressure, each minute, for a total of 5 minutes of exposure to heat.
  

Click here for a recording form.

QUESTIONS.

13. Graph the heart rate and blood pressure changes to heat vs cold. (5 pts) (Hint: Draw the graph so that it answers the following questions)

14. Were the changes in heart rate and blood pressure expected for cold and heat exposure?    What are the mechanisms of cardiovascular change in heat and cold? (10 pts)

VI. AMBULATORY BLOOD PRESSURE

    One volunteer from each lab session will wear the ambulatory blood pressure monitor for 24 hours.   The subject is not to shower or exercise during the ambulatory monitoring.  So, plan ahead.

QUESTION

15. Was the ambulatory blood pressure recording normal?     What would be expected of a 24 hour diurnal blood pressure? (5 pts) Attach the ambulatory report.

VII. Heart Rate Variability

One volunteer from each lab session will wear the Holter Monitor for 24 hours. The subject is not to shower or exercise during the ambulatory monitoring.  So, plan ahead.

QUESTION

16. Compare the nighttime heart rate to the daytime heart rate. Does the heart rate differ between these two periods? What is the possible neural control mechanism? (5 pts)

VIII. EXERCISE:   DAY TWO

    Use the same heart rate and blood pressure procedures as previously described.    Use the same subject so that comparisons between exercise modes can be made more easily.   In this part of the lab you will compare responses to continuous vs progressive loads and static vs dynamic exercise.    Exercise in the water will also be compared to exercise on the land.    Doing exercise above and below the head is also a part of this lab.   Dress appropriately.

Static Exercise, Continuous Load (low intensity)
  1. Randomize the order of continuous and the progressive work.
  2. Measure and record a resting heart rate and blood pressure for at least three minutes.
  3. Have subject perform a sustained static contraction at 40% of maximal force on a hand grip dynamometer.
  4. Measure and record heart rate and blood pressure every 30 seconds until fatigue (terminate early if the diastolic blood pressure exceeds 120 mmHg).
  5. Measure and record the heart rate and blood pressure every 30 seconds of recovery for 2 minutes.
Static Exercise, Progressive Loads
  1. Randomize the order of continuous and the progressive work.
  2. Measure and record a baseline heart rate and blood pressure for at least three minutes.
  3. Have subject perform the following protocol on the hand grip dynamometer.
    • 90 sec @ 20%
    • 90 sec @ 40%
    • 90 sec @ 60%
  4. (Terminate early if diastolic blood pressure exceeds 120 mmHg).
  5. Measure and record heart rate and blood pressure every 30 seconds during exercise and for two minutes of recovery.

High Intensity Static Exercise

1. Randomize the order of high vs low intensity static work
2. Measure and record resting heart rate and blood pressure for at least three minutes.
3. Have the subject perform a sustained wall sit for as long has he/she can (or until diastolic blood pressure exceeds 110 mmHg).
4. Measure and record heart rate and blood pressure every 30 seconds until fatigue
5. Measure and record heart rate and blood pressure every 30 seconds for two minutes of recovery.

 

  

Click here for a recording form.

Dynamic Exercise, Continuous Load
  1. Randomize the order of continuous work and the progressive work.
  2. Measure and record a baseline heart rate and blood pressure for at least three minutes.
  3. Have the subject pedal the cycle ergometer for 5 minutes at 600 kpm/min (50 rpm with load of 2 kp).
  4. Measure and record heart rate and blood pressure every minute of exercise and recovery (2 min.).
Dynamic, Progressive Loads
  1. Measure and record a baseline heart rate and blood pressure for at least three minutes.
  2. Have the subject perform the following protocol:
    • 5 min @ 300 kpm/min
    • 5 min @ 450 kpm/min for women or 600 kpm/min for men
    • 5 min @ 600 kpm/min for women or 900 kpm/min for men
    • 5 min of recovery
  3. Measure and record heart rate and blood pressure every minute.

Click here for a recording form.

QUESTIONS.

17. Graph the heart rate and blood pressure response to continuous static and continuous dynamic exercise. (5 pts) (Hint: Draw the graph so that it answers the following questions)

18. Graph the heart rate and blood pressure response to the low intensity static and high intensity static exercise (5pts). (Hint: Draw the graph so that it answers the following questions)

19. Compare the heart rate and blood pressure responses of continuous static and continuous dynamic exercise.    Explain the mechanisms of the differences and similarities. (5 pts.)

20. Compare the heart rate, blood pressure and double productheart rate and blood pressure response of low intensity and high intensity static exercise. Explain the mechanisms of the differences and similarities. (5 pts)

21. What influences the cardiovascular response in static exercise, muscle mass or percent maximal voluntary contraction?    Explain. (5 pts.)

22. To what extent is the cardiovascular response to static exercise a reflex? Explain these reflexes. (5 pts)

23. Graph the heart rate and blood pressure response to progressive dynamic vs continuous dynamic exercise. (5 Pts)

24. Compare the heart rate and blood pressure response of dynamic exercise during continuous vs progressive work.    What are the possible explanations for these differences? (10 pts.)

25. Did you get (or Would you expect) the same pattern of response for static, continuous vs progressive work?    Explain. (5 pts)

Tilt Posture Deep Breathing Drugs Ambulatory Blood Pressures Heat and Cold Exercise Water vs. Land exercise Exercise Above vs. Below the Head

 

            
E. Dynamic Water Exercise, Continuous Load
  1. Randomize the order of water work and land work.
  2. Measure baseline heart rate and blood pressure for, at least, three minutes.
  3. Have the subject jog in place for 5 minutes.
  4. Have the subject jog in place in the underwater weighing tank for 5 minutes.
  5. Make sure both jogs are done at the same cadence.
  6. Measure heart rate (palpation for the water exercise) and blood pressure every minute of the exercise for both conditions.

Click here for a recording form.

QUESTIONS.

26. Graph the heart rate and blood pressure response to water vs land exercise (5 pts).

27. Describe the similarities and differences in the cardiovascular adaptations to exercise between water and land exercise.   Explain the mechanisms for the differences, if any (10 pts)

            
F. Work Above and Below the Head
  1. Randomize the order of above and below conditions.
  2. Measure baseline heart rate and blood pressure for, at least, three minutes.
  3. Measure heart rate and blood pressure every 30 seconds while the subject turns the screw into the 2 by 4 under both conditions
    1. Above the head
    2. On a table

Click here for a recording form.

QUESTIONS.

28. Graph the heart rate and blood pressure response to work above vs below the head (5 pts)

29. Are the cardiovascular responses to work below and above the head similar or different?   Explain the mechanisms. (10 pts).

30. How accurate are exercise blood pressures, measured by auscultation? (5 points)

31. Graph the double product response to(on the same graph) (5 pts)

  • Continuous Static
  • Continuous Dynamic
  • Water Exercise
  • Land Exercise
  • Exercise Above the Head
  • Exercise Below the Head

32. Compare the double product among these modes of activity. Which mode makes the heart work hardest? (5 pts)

REFERENCES:
  1. Class notes.
  2. Most Exercise Physiology textbooks.
  3. Ewing, D.J., C.N. Martyn, R,J, Young, and B.E. Clark. The value of cardiovascular autonomic function tests: 10 years experience in diabetes. Diabetes Care 8: 491-498, 1985.
  4. Robertson, D., J. Frolich, K. Carr, J. Watson, J. Hollifield, D. Shand, and J. Oats, "Effects of caffeine on plasma renin activity, catecholamines and blood pressure," N. Eng J. Med. 298 (4); 181-186, 1978.
  5. Fardy, P.S., Isometric exercise and the cardiovascular system. The Physician and SportsMedicine 9: 43-53, 1981.
  6. Astrand, P.O., Textbook of Work Physiology, McGraw-Hill, 1977.
  7. Butts, N.K., M Tucker, and C. Greening. Physiological responses to maximal treadmill running and deep water running in men and women. The American Journal of Sports Medicine 19:612-614 1991.
  8. Yamaji, K., M. Greenly, D.R. Northey, and R.L. Hudson. Oxygen uptake and heart rate responses to treadmill and water running, Canadian journal of Sports Sciences 15:96-98, 1990.
  9. Wallace, J.P., P.G. Bogle, B.A. King, J.B. Krasnoff, and C.A. Jastremski. The magnitude and duration of ambulatory blood pressure reduction following acute exercise. Journal of Human Hypertension, 13:361-366, 1999
  10. Griffin, S.E., R.A. Roberts, and V. H. Heyward. Blood pressure measurement during exercise: A review. Medicine and Science in Sports and Exercise 29:149-159, 1997.
  11. Iellamo, F., M Massaro, G. Raimondi, G. Perizzi and J.M. Legramante, Role of muscular factors in cardiorespiratory responses to static exericse: contribution of reflex mechanisms. J Appl Physiol 86:174-180, 1999.
  12. Daniels, J.W., P. A. Mole, J.D. Shaffrath, and C.L. Stemmins. Effects of caffeine on blood pressure, heart rate, and forearm blood flow during dynamic leg exericse. J Appl Physiol 85:154-159, 1998.
  13. Furlan, R., S. Guzzetti, W Crivellaro, S. Dassi, M. Tinelli, G. Baselli, S, Cerutti, F. Lombardi, M. Pagani, and A. Malliani. Continuous 24- hr assessment of the neural regulation of systemic arterial pressure and RR variabilities in ambulant subjects. Circulation 81:537-547.

Electronic Reading Reserves can be found at http://ereserves.indiana.edu/coursepage.asp?cid=574&page=01

Password = aerobics

 

This page was last updated 26 August 2005
URL: http://www.indiana.edu/~k561
Webmaster: Janet P. Wallace, PhD, FACSM
Contact:wallacej@indiana.edu
Copyright 1998, The Trustees of Indiana University