Transcript Clark Cotton Module 2 Module 2 PowerPoint

Learning Module 2:
Measuring ECG’s
Clark J Cotton
Calculating Heart Rate from an ECG
•
By measuring the distance
between R-waves, we can
calculate heart rate.
•
Example:
– 1 sec between R-waves.
– HR = 60 / 1 = 60 beats / minute
Calculating Heart Rate from an ECG
•
By measuring the distance
between R-waves, we can
calculate heart rate.
•
Example:
– 1 sec between R-waves.
– HR = 60 / 0.5 = 120 beats / minute
What Are Activities that Could
Influence Heart Rate?
•
Fill in with ideas as students brainstorm
Why Does Heart Rate Change?
•
Again fill in with ideas as students brainstorm.
Measuring Your ECG
1.
Wipe each wrist and your right
ankle with an alcohol pad.
2.
Attach gel-electrode pads to
each wrist and your ankle.
3.
Attach the red wire to your right
wrist, the black wire to your left
wrist, and the green electrode to
your ankle.
4.
Click record on your laptop.
Once you see a good ECG with
5-10 heartbeats click stop.
5.
Calculate Heart Rate
Typical Resting Heart Rates
African Elepant
Resting HR 28 bpm
Sam Donaldson
Resting HR 75 bpm
Deer Mouse
Resting HR 500 bpm
Test the Effects of Jumping Rope
1.
Detach the wires from your gel
electrodes.
2.
Jump rope for 5 minutes.
3.
Re-attach the red wire to your
right wrist, the black wire to your
left wrist, and the green electrode
to your ankle.
4.
Click record on your laptop.
Once you see a good ECG with
5-10 heartbeats click stop.
5.
Calculate heart rate.
Effect of Exercise on Heart Rate
Race Horse
Rainbow Trout
Resting 25 bpm
Resting HR 47 bpm
Racing 215 bpm
Swimming HR 50 bpm
Test the Effects of Diving
1.
Hold your face directly over a
tub of ice water.
2.
Click record on your laptop.
Once you see a good ECG have
your subject slowly immerse
their face in the water.
3.
Keep recording for as long as
your subject can stay under
water.
4.
Calculate the heart rate for the
last few beats you see while the
subject is still under water.
Diving Bradycardia in Nature
Harbor Seal
HR before dive = 135 bpm
HR during dive = 30 bpm
Double-Crested Cormorant
HR before dive = 210 bpm
HR during dive = 50 bpm
Why is Diving Bradycardia Adaptive?
•
During a dive, animals have no
access to oxygen.
•
To conserve oxygen, animals
reduce blood flow to all but the
most important areas (heart,
brain).
•
Since blood flow is greatly
reduced, the heart only needs to
supply blood to a limited area,
and can therefore reduce its
rate and oxygen consumption.
Bron et al. 1966