EKG V & VI Flashcards
What are the 4 types of AV blocks?
1) 1st degree
2) 2nd degree Mobitz I (Wenckebach)
3) 2nd degree Mobitz II
4) 3rd degree
What interval is key in reading an EKG when differentiating between AV blocks?
PR interval (normal: 0.12-0.20 sec)
EKG is normal except the PR interval is prolonged, at a constant duration, in ALL beats. What type of block is this?
First-degree AV block, PRI > 0.20 sec (1 big box) in ALL beats
What type of EKG abnormality is this?
First-degree AV block
You’re looking at an EKG and the PR interval gets longer and longer until a beat completely drops off (P wave, but no QRS). What type of block is this?
Second-degree AV block: Mobitz Type I (Wenckebach)
What type of block is this: the PR interval remains constant (can be normal or long) until a beat is dropped
Second-degree AV block: Mobitz II
What type of block is more dangerous, second-degree AVB Mobitz I or Mobitz II?
Second-degree AVB Mobitz II - this often progresses into a complete block
True/False: AV blocks will always have a P wave
True, the SA node is firing, but the impulse gets blocked or delayed at the AV junction in an AV block
In this type of block, the atria and ventricles beat independently, with NO communication between the two. P-P is regular & R-R is regular
Third-degree AVB (AKA Complete heart block)
These types of blocks are caused by a delay or interruption in the transmission of impulses occurring below the bifurcation of the Bundle of His
Bundle branch blocks (RBBB or LBBB)
What leads are you looking at on an EKG when diagnosing BBBs?
V1 and V6 (looking at R-R’)
QRS complex is usually wide (>0.12 sec)
Which BBB is more dangerous, left or right?
LBBB never occurs in a healthy heart. These are concerning, especially if it’s new
What are some possible causes of a RBBB?
- Coronary artery disease
- HTN
- Acute PE
- Chronic electrical degeneration
- Can occur in a healthy heart
What are some common causes of a LBBB?
- HTN
- Cardiomyopathy
- Acute MI
- Aortic stenosis
- Extensive CAD
- Diseased electrical system
*Most often due to an organic heart disease, does NOT occur in a healthy heart
What characteristic feature will you see in the R waves in the V6 lead during a LBBB?
“Rabbit ears”
If you’re using the turn signal method of determing R vs L BBB, what direction is this BBB?
RBBB, you are looking at V1 - you click your turn signal UP to turn Right (LBBB also has the “rabbit ears” in V6)
When looking at BBB, the deflection of the QRS is going the opposite direction of the T wave. What is this called? Is it good or bad?
This is called discordance, and it’s good
The QRS deflection is going the same direction as the T wave in a BBB. What is this called? What does it suggest?
This is concordance, it may suggest ischemia or myocardial infarction
What is the Sgarbossa criteria tool used for?
It is used to identify an MI in the presence of a LBBB
_______ refers to reduced blood supply secondary to partial occlusion or spasm, heart muscle is savable.
________ refers to no blood supply due to full vessel occlusion, the heart muscle is dead.
Ischemia refers to reduced blood supply secondary to partial occlusion or spasm, heart muscle is savable.
Infarction refers to no blood supply due to full vessel occlusion, the heart muscle is dead.