ECG

Question 1

3 main causes of AV dissociation

Answer 1

Depressed SA node automaticity
Increased AV junctional or ventricular automaticity
Disturbed AV conduction

Question 2

What is a clue on the surface ECG that there is an atrial echo beat?

Answer 2

PR prolongation of the conducted beat allows for the atrial myocardium to repolarize and re-depolarize after the impulse is returned

Question 3

Pacemaker pacing in both atria and ventricle?

Answer 3

dual chamber

Question 4

2 things responsible for pacemaker syndrome

Answer 4

Loss of av synchrony

retrograde av conduction

Question 5

Describe pacemaker mediated tachycardia.

How can it be avoided.

Answer 5

In VDD or DDD, atrial event is sensed or paced, triggers ventricular pacing which may conduct retrograde to AV node and redepolarize atria, this will be sensed and ventricular pacing will occur, causing tachycardia.
Adjust PVARP to encompass retrograde atrial activation.

Question 6

What is pacemaker Wenckeback and what is the maximal AVD prolongation?
How do you create PMWCK?

Answer 6

Progressive prolongation of AV interval when atrial rate is detected to be at upper tracking interval/maximum tracking rate (UTI/MTR) until p wave occurs in the PVARP and is not tracked. Next AVD is normal and the cycle continues.
Maximal AVD prolongation corresponds to the difference between the MTR and TARP.
To create it, decrease MTR.

Question 7

Acronym to remember which is the cathode and which is the anode.

Answer 7

PANIC
Positive: anode
Negative: cathode