EKG the Basics Flashcards
What is a 12 lead EKG?
12 views, 12 pictures of the EKG. Separated by hasmarks
How long is the standard EKG?
10 seconds
What is the standard speed of the paper? What if this is not?
25 mm/sec
Can throw the calculations off
What is amplitude AKA? What is it? What is standard settings?
AKA gain
bigger the gain
limb = 10
chest = 10
This is standard, and gives criteria
What do you do first for an EKG?
Confirm it is the right patient
Does EKG require informed consent?
No
What can an EKG show?
Structure of heart
r/r of heart
electricity of the heart
plumbing of the heart
toxic effects of medications
If you suspect an MI, what’s the first thing you order?
an EKG
What are the downsides of EKG?
artifacts
interpretation error
performance error (have to put leads in the right place)
Only get 10 seconds - if they are not actively having chest pain it might not show up
What makes the lines in the EKG?
Depolarization and repolrization of myocardial cells
SA node, AV node, and Perkinje fibers are too small to pick up
What is the electrical system of the heart
SA node (in right atrium) to AV node, which splits to left bundle branch and right bundle branch that depolarize at the same time
What leads to a higher amplitude in an EKG?
The amount of myocytes
What is the amplitude and seconds of each box?
0.04 sec
0.1 mV
What is the first
P (atrial deploarization)
R
T = ventricular relaxation
What is the QRS?
Ventricular depolarization
What is the Q?
The first negative deflection if there is one
What is an S?
If R goes below the baseline
What is an RSR’?
Goes down, but it does not cross the baseline
What are interval vs segment?
Interval = includes the
PR segment = AV node that allows ventricular filling, the longer this is the more it can fill
ST segment = ventricle squeeze
QT interval = ventricular depolarization and repolarization
What are the 3 types of cells that make up the electrical system of the heart
Pacemaker
Conduction cells
Myocytes
QRS
ventricular dep
P wave
atrial depolar
atrial repolar
happens in QRS, meaning you don’t see it
What are the 12 leads for?
To get different views, and may change the waveform depending on how close they are.
Set up like cameras (electricity towards one camera)
What is depolarization of an EKG dependent on?
Depolarization
Moving TOWARD an electrode – POSITIVE deflection
Moving AWAY from an electrode – NEGATIVE deflection
Repolarization
Moving TOWARD an electrode – NEGATIVE deflection
Moving AWAY from an electrode – POSITIVE deflection
What are the 4 electrodes on the limbs?
RA (right arm)
LA
RL
LL (left leg)
Where are V1 and V2?
V1 = Right atrium and right ventricle
deflection will look negative because the V1
V2 = Left atrium/ left ventricle
What limb leads do you do?
