Pacing & Defibrillation

ECG

Library

News

Back

Discrimination and atrioventricular conduction disorders - Amplia Quad CRTD

Patient

Male implanted with a triple-chamber defibrillator (Amplia Quad CRTD) for ischaemic cardiomyopathy with complete atrioventricular block.


Trace


1- What is the diagnosis made by the defibrillator for this episode?
This episode has been classified as FVT by the device.

2- How many detection zones are programmed?
Two detection zones have been programmed.

3- What diagnosis does the interval plot suggest?
The graph initially shows a synchronised atrioventricular rhythm, then acceleration of the ventricular rhythm into the FVT zone with atrioventricular dissociation; a burst interrupts the tachycardia.

4- How many discrimination parameters are programmed?
All discrimination parameters (stability, sudden onset, PR Logic, Wavelet) are set to Off.

5- What is the initial rhythm?
As expected in a resynchronised patient, the patient is initially sensed in the atrium and paced biventricularly.

6-What is your diagnosis?
It is a VT with atrioventricular dissociation

7- What is the effect of the burst?
The burst terminates the arrhythmia.

Take home message

  • This patient had been implanted for primary prevention of ischaemic cardiomyopathy; he also had complete atrioventricular block justifying permanent ventricular pacing and the implantation of a triple-chamber defibrillator.
  • There are now international recommendations for defibrillator programming, but these need to be tailored to the specific needs of each patient.
  • In this patient, the discrimination had been programmed ‘Off’; in fact, the discrimination algorithms should only be programmed in patients likely to present with conducted supraventricular tachycardia and should therefore be deactivated in patients with complete and permanent atrioventricular block; in this case, any rapid spontaneous rhythm can only be of ventricular origin.

X