Transcript Blood Pressure - SHMD 349 Sport & Exercise Technology 3

13/3/2012
SHMD 349
Pg 34
 Blood pressure is the pressure the blood exerts on
the artery walls
 Blood pressure (BP) is the result of the heart contracting
and forcing blood into the blood vessels
 BP is necessary in order for blood to flow around the body
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Pg 34
 Typical BP for the average person:
120
80
Systolic:When the heart is contracting
Diastolic: When the heart is relaxing
 BP unit of measurement:
milligrams of mercury (mmHg)
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Pg 33
 Cardiac Output: the amount of blood pumped from the heart
every minute
 Stroke Volume: The amount of blood pumped by the left
ventricle of the heart in one contraction.
 Heart Rate: the number of times the heart beats in 1 minute,
measured in beats per minute (bpm)
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Pg 34
 Cardiac Output (litres per minute) = heart rate (bpm) x Stroke volume
(litres)
 Thus, Q = HR x SV
 The average stroke volume is 70 – 90 millilitres (ml)
 The fitter you are, the larger your SV is
 At rest, your cardiac output (Q) is ± 5 litres per minute (L/m), while
during exercise it can increase to as much as 30 L/m
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Pg 34
 Blood Pressure (mmHg) = Cardiac Output (litres per
minute) x Resistance to flow (R)
 Thus, BP = Q x R
 Resistance to blood flow is caused by:
1.
Size of the blood vessels. i.e. The smaller the blood vessel, the
greater the resistance
2.
Thickness of the blood. i.e. The thicker the blood, the greater the
resistance.
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 If heart rate = 72 bpm
 & stroke volume = 85ml
 Cardiac output?
 85ml ÷ 1000 = 0.085L
 Thus,
 Q
= HR x SV
= 72 x 0.085
= 6.12 L/m
Round off = 6 L/m
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 If heart rate = 68 bpm
 & stroke volume = 80ml
 Cardiac output?
Diastolic R = 14
Systolic R = 22
Blood Pressure?
 80ml ÷ 1000 = 0.080L
 Thus,
 Q
= HR x SV
= 68 x 0.08
= 5.44 L/m
 Systolic BP
=QxR
= 5 x 22
= 110 mmHg
 Thus BP
Diastolic BP
=QxR
= 5 x 14
= 70 mmHg
= 110 mmHg
70
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Pg 34
 Exercise increases heart rate, which will result in an increased
cardiac output, which will increase blood pressure
 Q = HR x SV
 BP = Q x R
 If Q is increased, and R does not change, then BP will
automatically increase
 Exercise raises systolic BP, but there is usually only a slight
change in diastolic BP
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Pg 132
 Is a repeatedly elevated blood pressure exceeding 140
over 90 mmHg, and means high pressure (tension) in
the arteries.
 If a person with high blood pressure does not reduce
their BP, they are more at risk of suffering a stroke or
heart attack .
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Pg 35
 Used by heavy weightlifters
 Process of breathing against a closed glottis or against a
closed mouth & nose
 The valsalva maneouvre helps stabilise the shoulder girdle
and torso while lifting heavy weights. This helps the lifter
to move the weight more efficiently.
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Pg 36
 The valsalva maneouvre causes BP to increase, and reduces
blood flow to the thoracic cavity
 Thoracic cavity: part of the body that is enclosed by the ribcage and the
diaphragm, containing the heart and lungs
 Therefore anyone suffering from hypertension or heart
problems should avoid this move, as it could cause a stroke
or heart attack.
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Pg 167
 It is vital to measure BP before a client exercises, as it will
tell you if they are at risk of having a heart attack.
 BP is measured with a blood pressure meter and
stethoscope.
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Pg 167
1.
The client should be seated and relaxed for 5 minutes
2.
Ask the client to rest their left arm on the arm of the chair. Their elbow
should be at 45 degrees, with the palm of the hand facing up.
3.
Find the brachial pulse – it should be on the inner side of the arm, just
under the biceps muscle.
4.
Place the cuff just clear of the elbow (about 2-3cm above the elbow). The
bladder of the cuff (The part which inflates) should be directly over the
pulse.
5.
Place the earpieces of the stethoscope in your ears and place the
microphone over the brachial pulse.
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Pg 167
6.
Inflate the cuff up to 200mmHg.
7.
Slowly open the valve by turning it anti-clockwise and release the pressure.
8.
Listen out for the first time you hear the thud of the heart beat and make a
mental note of it. This is the systolic blood pressure reading.
9.
Keep deflating the cuff, and when the heart beat becomes muffled or
disappears, this is your diastolic reading.
10.
Keep deflating the cuff and, if necessary, repeat
after around 30 seconds.
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Classification of blood pressure for adults
Category
Systolic (mmHg)
Diastolic (mmHg)
Desirable
90 – 119
60 – 79
Prehypertension
120 – 139
80 – 89
Stage 1 Hypertension
140 – 159
90 – 99
Stage 2 Hypertension
160 – 179
100 - 109
≥180
≥ 110
Hypertensive Crises
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1.
Define:
Blood pressure.
b. Cardiac output.
c. Stroke volume.
d. Hypertension.
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2
2
2
a.
2. What do the following abbreviations stand for:
BP.
b. Q.
c. SV.
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2
2
a.
3. Differentiate between ‘systolic’ and ‘diastolic’ blood pressure.
4. Provide the unit of measurement for:
Blood pressure.
b. Cardiac output.
c. Stroke volume.
a.
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1
1
1
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Provide the average stroke volume of a person at rest?
6. Does stroke volume ever change? If so, when?
7. Provide the average value of cardiac output at rest, as well as during
exercise.
8. List and briefly explain the 2 factors that cause resistance to blood flow.
9. How does exercise affect blood pressure?
10. What are the implications of a high BP?
11. Explain:
5.
The valsalva manoeuvre.
b. Who uses it,
c. And why.
a.
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2
2
4
5
2
3
2
2
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12. Should someone with a high BP perform the valsalva maneuver?
13.
14.
15.
16.
Why/why not?
3
Which two instruments are used to measure BP?
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Why is it important to measure BP before an individual performs exercise
testing?
3
Explain the procedure for measuring blood pressure.
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In tabular form, write down the norms for blood pressure.
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Calculate:
1. Calculate cardiac output (Q) of a person at rest; if their heart rate is 72 bpm,
and their stroke volume is 75 ml (0.075L).
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2. Calculate the cardiac output of a person who is training at a high intensity; if
their heart rate is 180 bpm, and their stroke volume is 140ml (0.14L).
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3. Calculate blood pressure, if Q = 5L/m, systolic R = 23, and diastolic R = 15.
Also, classify which category this blood pressure reading falls into.
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4. Calculate blood pressure if:
 Heart rate = 75 bpm
 Stroke volume = 80ml (remember to convert to liters)
 Systolic R = 24
 Diastolic R = 16
 Also, classify which category this blood pressure reading falls into.
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