Your Electrical Heart
Exploring EKG
Objectives
• Find and interpret patterns on an
EKG graph
• Describe the electrical and
mechanical components of a normal
heart rhythm
• Draw appropriate conclusions about
the mechanics of various normal
and abnormal heart functions based
on EKG
Introduction
• When have you heard the terms “Vtac”, “V-fib”, “asystole”?
Depiction of electrical
• What is an EKG or ECG? activity in the heart
• What do you think a normal graph of
the heart’s electrical activity looks
like? (draw it)
• Why do doctors and nurses need
EKGs? Detect & diagnose problems
with the patient’s heart rhythm
Review and new terms
• Left & right atria: receive blood from the
veins, pump it into ventricles
• Left & right ventricles: receive blood from
atria, pump it out into arteries
• Sinoatrial (SA) node: bundle of nerves in R
atrium, the heart’s pacemaker, stims
contraction of atria
• Atrioventricular (AV) node: between atria &
ventricles, continues rhythm set by SA node,
stims contraction of ventricles
• Purkinje fibers: fan out and stimulate
contraction of ventricles
Review: the cardiac cycle
• How blood moves through the heart
1.Blood enters atria>>pressure in A
rises>>AV valves open
2.Blood enters ventricles>>pressure in
V rises>>AV valves
close>>semilunar valves
open>>blood leaves heart
3.Pressure in V falls>>S/L valves close
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2.
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6.
To Do and Notice
Look at your EKG strip.
Determine the patient’s heart rate in BPM
if this is a 6 second rhythm strip.
Is the rhythm consistent? (describe)
How is your strip similar to a normal
EKG? How is it different?
Based on what you know about the
cardiac cycle, try to explain what is going
wrong with this heart.
Present your patient to the class.
What’s Going On?
• What terms and conditions do we
learn from the EKGs?