Quiz 9 - Junctional Arryth.

Question 1

What is a junctional rhythm?

Answer 1

An impluse originating in the AV node.

Its usually slow (40 - 60), but can be accelerated (60 - 100) or Paraoxysmal (suddenly >100)

Question 2

What are teh characteristics of a junctional rhythm?

Answer 2

HR = normal BUT P waves are absent or inverted (meaning atri. depolarized b4 vent); or can be hidden in QRS (meaning vent and atri. depolarized at same time; therefore no visual p wave) OR come right AFTER it instead (meaning vent. depolarized 1st).
PR interval = ≤ 10 and QRS = Normal

Question 3

What are some causes of junctional rhythms?

Answer 3

ELectrolyte imbalance, myocarditis, idiopathic

Question 4

What is distinctive about 1st degree AV block?

Answer 4

Everything is “normal” (looks like NSR) EXCEPT the PR interval - Its prolonged usually by 0.20 aka 5 small boxes or greater!
(Children and athletes can see incidence; no symptoms, no major treatment (unless SUPER slow i.e brachy. and meds to to be given - rare to none)

Question 5

What do AV heartblocks describe?

Answer 5

A delay of conduction (or failure) of the AV/His region..

Blocks are classified by severity (1-3)

Question 6

What does a 1st degree AV block tell us?

Answer 6

There was a delay of conduction atrial (impulse) to ventricles

Question 7

What does Mobitz type II 2nd degree AV block tell us?

Answer 7

Some atrial impulses conducted to ventricles but others (intermittently failed); hence the lack of QRS to EVERY pwave

Question 8

WHat does Mobitz II 2nd degree AV block look liek on an EKG?

Answer 8

2 - 3 normal p waves before a QRS

Question 9

What does Mobitz Type I 2nd degree AV block tell us?

Answer 9

It was a delayed conduction FOLLOWED by failure of SOME atrial impulses to the ventricles.

(usually has pattern since progressively prolonged until QRS drops; then the pattern repeats)

Question 10

In a bundle branch, where does the abnormality you are looking for take place?

Answer 10

In the ventricles/QRS (bc everything else is “normal”)

*Greater than 12 small boxes

Question 11

What are the characteristics of a right bundle branch block?

Answer 11

QRS will be >0.12
V1 will have the rabbit ears/M-shape (r, r-prime) - may be present in V2 and V3
Later leads - V6, lead 1 and lead AVL will have that slured and wide S (to T) shape/inversion