Spontaneous termination of a ventricular arrhythmia - Claria CRT-D

Patient

Patient with ischaemic cardiomyopathy implanted with a triple chamber defibrillator (Claria CRT-D).

Comments

What diagnosis are you suggesting on this graph?

The graph shows a sudden acceleration of the ventricular rate with cycles detected in the VF zone; the initial VF counter is completed (Detection) but no therapy is delivered following a probable spontaneous reduction.

What type of arrhythmia is it?

This is probably a very rapid ventricular arrhythmia.

How is the initial detection counter in the FV zone programmed?

The initial counter is set to 30/40.

What does abandonment mean?

Charging of the capacitors starts when the initial FV counter is completed; during charging, the arrhythmia stops spontaneously and after 4 consecutive cycles classified as BV, charging is interrupted (discontinuation of therapy).

Take home message

This episode corresponds to a polymorphic ventricular tachycardia which resolves spontaneously after about ten seconds.
This patient had multiple episodes of non-sustained ventricular tachycardias recorded in the device’s memories and defined by the occurrence of at least 5 consecutive cycles in one of the detection zones without any of the initial counters being filled (VT or VF) and a few episodes, like this example, where the counters were filled with the charge interrupted.
Programming the number of cycles of the initial counter is crucial not only for the patient’s quality of life but also for his prognosis; today, it is recommended that the initial counter in the VF zone should be programmed for 30/40 cycles as a first-line treatment; results from large numbers of patients have shown that this programming significantly reduces the number of inappropriate therapies (expected result) but also the number of appropriate but avoidable therapies, as the arrhythmia reduces spontaneously.

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