EKG Flashcards
Why do we use lead II in the OR?
It’s best for detecting arrhythmias
How long should the PR interval be? First degree heart block is: __.
Is the shape of waveform changed with 1st degree heart block?
no more than 0.2 seconds
First degree heart block is PR interval greater than 0.2 seconds. Shape of wave is unchanged.
Second degree heart blocks:
Mobitz 1: Repeating cycles of lengthening PR intervals until there is a dropped beat.
Mobitz 2: Dropped beats with uniformly prolonged PR interval (randomly dropped beat)
Third degree AV block:
Which blocks require cardiac pacing?
complete dissociation of atria and ventricles. There is NOT a QRS complex after every P wave
Second degree type 2 blocks and third degree heart blocks require cardiac pacing
How long should Q waves be?
0.03 seconds. Greater than that-transmural infarction. Prolonged q wave is a post infarction scar
How long is the QRS:
What can you be on the lookout for if its longer?
0.12 seconds
Longer=block in bundle of His, you can look for bundle branch blocks here too
When do you suspect RBBB?
Causes of RBBB:
if there is an R and R’ in lead V1.
CAD, HTN, Scar tissue, PE, Anterior wall MI
When do you suspecdt LBBB?
If there is an R and R’ in lead V6
Causes of LBBB:
Anterior wall MI, aortic stenosis
ST segment: if depressed vs elevated:
Most sensitive lead for diagnosis of ischemia is ___
depressed: myocardial ischemia
elevated: myocardial necrosis
Chest lead V5
What is the T wave:
How long should it be
Shouldn’t have a higher amplitude than: ___
ventricular repolarization
should not be longer than 0.2 seconds
Should be concordant with total amplitude of QRS complex
What are the ASA recommendations for a pre-operative EKG?
Age greater than 50
Good for one year if age 50-69
Good for 6 mos if >69
Hx of CV disease or HTN
EKG mandatory if pt has change in cardiac symptoms
Also, EKG needed if pt has DM and is older than 40 or If pt has had DM for greater than 10 years (regardless of age)
CNS disease requires one too
