Cardiac Disorders and 12 Lead EKG Part 5 Flashcards
Views the heart in a vertical plane is synonymous with what plane?
frontal plane
In this frontal plane image, limb leads view heart’s electrical activity (depolarization & repolarization) moving in what directions (name in order) through this circle?
up, down, right, and left
What lead is this?
LA +
RA -
Angle of orientation is ___º
Lead I
0
What lead is this?
Legs +
RA -
Angle = ____º
Lead II
60
What lead is this?
legs +
left arm -
Angle is ____º
III
120
What lead is this?
left arm +
other limbs -
Angle is ____º
aVL
-30
What lead is this?
RA +
Other limbs -
Angle is ___º
aVR
-150
What lead is this?
Legs +
Other limbs -
Angle is ___º
aVF
90
The 6 precordial leads arranged across chest in horizontal plane, views heart’s electrial activity moving _______ and ______.
anteriorly & posteriorly
What lead is placed at 4th ICS right of sternum?
V1
What lead is placed at the 4th ICS left of sternum?
V2
What lead is placed at the 5th ICS in the midclavicular line?
V4
Lead V3 is placed where?
between V2 and V4
What lead is placed in the 5th ICS in the midaxillary line?
V6
Where is lead V5 placed?
between V4 and V6
Inferior leads are what 3 leads?
II
III
aVF
Left lateral leads are what leads? (4)
I
aVL
V5
V6
Anterior leads are what leads? (2)
V3
V4
Lead aVR is _____.
alone
Light lines on the EKG, small boxes are __ x___mm squares.
1x1
Dark lines, or large box on the EKG strip are ___x___ mm squares
5 X 5
Small square distance = ____ sec
0.04
Large square distance= ____sec
0.2
Vertical axis on EKG strip is _____.
voltage
Horizontal axis or EKG strip is _____.
time
Each small square on y-axis is ___mV
0.1
Each large square on y-axis is ____mV.
0.5 mV
Atrial depolarization begins at SA node and is indicated on the EKG as ______.
P wave
___ wave
Vector of current flow points from R→L and inferiorly.
P wave
The P Wave
Any lead that views the wave of atrial depolarization as moving toward it will record a ____ deflection (I, aVL, II, aVF, V5, V6)
positive
The P Wave
As moving perpendicular to it will record a ____ wave (III V1)
biphasic
The P Wave
As moving away from it will record a ______ deflection (aVR)
negative
What represents the time from the start of atrial depolarization to the start of ventricular depolarization including delay in conduction from AV node?
PR Interval
PR interval = ____-____seconds
0.12 - 0.2
Definition: The interventricular septum depolarizes left-to-right and a small negative deflection can be seen in: I, aVL, V5, and V6.
Septal Q-waves
Definition: Ventricular (LV) depolarization current vector points 0-90º.
Large positive R waves are seen in (I, II, III, aVL, aVF, V5, V6,) and negative R wave in aVR. *
Note: R wave progression in precordial leads.
QRS complex
This represents the time from the end of ventricular depolarization to the start of ventricular repolarization
ST segment
This represent repolarization that usually begins in the last area of the heart to have been depolarized.
T wave
What encompasses the time from the beginning of ventricular depolarization to the end of ventricular repolarization?
QT interval
QT duration is proportionate to what?
HR
What composes 40% of the cardiac cycle?
QT interval
What leads are interventricular septum leads? (2)
V1 and V2
