List four reasons why the AV junction may assume responsibility ...

[LaDunn]

List four reasons why the AV junction may assume responsibility for pacing the heart.
 
  What will be an ideal response?

Question 2

Complete the following ECG criteria for a junctional escape rhythm:
 
  Rhythm ___________________ ___________________ __
  Rate ___________________ ___________________ __
  P waves ___________________ ___________________ __
  PR interval ___________________ ___________________ __
  QRS duration ___________________ ___________________ __
 
  Fill in the blanks with correct word

[batool]

Answer to Question 1

The AV junction may assume responsibility for pacing the heart if: (1) the SA node fails to discharge (such as sinus arrest), (2) an impulse from the SA node is generated but blocked as it exits the SA node (such as SA block), (3) the rate of discharge of the SA node is slower than that of the AV junction (such as a sinus bradycardia or the slower phase of a sinus arrhythmia), (4) an impulse from the SA node is generated and is conducted through the atria but is not conducted to the ventricles (such as an AV block).

Answer to Question 2

Rhythm Regular.
Rate 40 to 60 beats/min.
P waves May occur before, during, or after the QRS; if visible, the P wave is inverted in leads II, III, and aVF.
PR interval If a P wave occurs before the QRS, the PR interval will usually be 0.12 sec or less; if no P wave occurs before the QRS, there will be no PR interval.
QRS duration 0.11 seconds or less unless abnormally conducted.