Chapter 9 Flashcards
What is the SA node?
the pacemaker of the heart
How many impulses does the SA node produce
per minute?
75
What does Limb lead 1 measure?
electrical potential between the right and left
arm
What does Limb lead 2 measure?
electrical impulse between the right are and left
leg
What does limb lead 3 measure?
electrical impulse between the left arm and left
leg?
What is Lead AVR?
Leads that are connected to the right arm, left
arm, and left leg.
Which is the positive electrode in lead AVR?
The right arm
What is lead AVL?
Leads that are connected to the left arm, right
arm, and left leg?
What is the positive electrode in lead AVL?
The left arm
What is lead AVF?
leads that are connected to the left leg, right arm,
and left arm.
What is the positive electrode in lead AVF?
left leg
Where is lead V1 located?
4th intercostal space at right border of the
sternum
Where is lead V2 located?
4th intercostal space at left border of the
sternum
Where is the lead V3 located?
positioned in a straight line between leads 2 & 4
Where is V4 located?
midclavicular line at 5th intercostal space
Where is lead V5 located?
axillary line level with lead 4 horizontally
Where is lead V6 located?
midaxillary line level with lead 4 & 5 horizontally
Where is the 1st electrode place?
upper right side of the chest
Where is the 2nd electrode place?
lower left side of the chest
Where is the 3rd electrode placed?
Used as a ground and may be attached to any
location that is convenient
What is the p-wave?
represents atrial depolarization
(contraction)
What is the Q-wave?
negative wave that follows the p-wave
may be absent
What is the R- wave?
positive wave that follows the Q-wave
What is the QRS complex?
(contraction)
What also happens during the QRS complex that
isn’t seen on the ECG?
Atrial repolarization
A widened QRS complex is seen with what?
Right bundle branch block
PVCs
What is the T - wave?
positive wave
represents ventricular repolarization
What does an inverted T - wave indicate?
coronary artery disease
How is the is the PR interval measured?
measured from the beginning of p-wave to
beginning of q-wave
What does the PR interval represent?
time it takes for the impulse to travel from SA
node to AV node
What is the duration of the PR interval?
0.12-0.20
If the PR interval is prolonged what does it
mean?
1st or 2nd degree heart block
How is the ST segment measured?
from the end of the S-wave to the beginning of
the T-wave
What does the ST segment measure?
The time required for ventricular repolarization
to begin
If the ST segment is elevated or depressed
above or below the baseline this indicates what?
cardiac ischemia
If the ST segment is elevated or depressed what
does that mean?
coronary artery disease
What is sinus bradycardia?
HR <60 bpm
What is the rhythm for bradycardia?
regular
What are some wave pattern abnormalities for
bradycardia?
none
What are some causes of sinus bradycardia?
hypothermia
Increased ICP
What is the treatment for bradycardia?
atropine
What is sinus tachycardia?
HR 100 -160 bpm
What is the rhythm for sinus tachycardia?
regular
What are some wave abnormalities for sinus
tachycardia?
none
what are some causes of sinus tachycardia?
hypoxemia
What is the treatment for sinus tachycardia?
treat the underlying cause & beta blockers
What is sinus arrhythmia?
HR 60-100 b/min
what is the rhythm for sinus arrhythmia?
irregular
what is the wave pattern for sinus arrhythmia?
R to R intervals may be longer than 0.16
seconds
What is significant about sinus arrhythmia?
the R wave and QRS complex varies and is
inconsistent
what is the cause of sinus arrhythmia?
none
what is the treatment for a sinus arrhythmia?
none
What is the rate for a PAC?
60-100 b/min
less than 6 PACs indicates what?
minor arrhythmia
more than 6 PACs indicates what?
major arrhythmia
What is the rhythm for a PAC?
Regular except for PAC
what is wave pattern abnormality for a PAC?
Premature p-wave looks different from a sinus p
-wave
what are some causes for a PAC?
CNS disturbances
what is the treatment for a PAC?
if more than 6 PACs per minute use lidocaine
What is the rate for a PVC?
60-100 b/min
Less than 6 PVCs per minute is considered
what?
minor
More that 6 PVCs per minute is considered
what?
Major
What is the wave pattern for a PVC?
the shape of the QRS complex is abnormal and
wider than 0.12
What are some causes of PVCs?
ventricular irritability caused by hypoxia
acid base disturbances
electrolyte abnormalities
excessive dose of digitalis
What is the treatment for a PVC?
Lidocaine
procainamide
What is the rate for A-fib?
greater than 350
What is the rhythm for A-fib?
irregular
What is the wave pattern for A-fib?
the p-waves cannot be distinguished and there is
an uneven baseline; PR interval is also
What are some causes of A-fib?
arteriosclerotic heart disease
mitral stenosis
valvular heart disease
What is the treatment for A-fib?
cardioversion
proponalol
digitalis
What is the rate for atrial flutter?
200-400 b/min (atrial)
60-150 b/min (ventricular)
what is the rhythm for A-flutter?
regular or irregular
what are some causes of A-flutter?
hypoxia
What is the treatment for A-flutter?
cardioversion
carotid artery massage
procainamide
digitalis
What is the rate for V-tach?
140-200
What is the rhythm for V-tach?
regular
What is the wave pattern for V-tach?
2.
What are some causes of V-tach?
arteriosclerotic heart disease
coronary artery disease
myocardial ischemia
what is the treatment for v-tach?
CPR
What is the rate for V-fib?
cannot be determined
what is the rhythm for v-fib?
cannot be determined
wave pattern
no distinguishable waves
what are some causes for v-fib?
hypertensive heart disease
