Patient
Male implanted with a dual-chamber defibrillator (Cobalt DR) for ischaemic cardiomyopathy.
Tracé
- What diagnosis is suggested by the interval
plot?
Three detection zones were programmed: a VT zone from 360 ms, a FVT zone from
310 ms and a VF zone from 280 ms; the episode was classified as FVT by the device (1);
the plot shows probable VT with atrioventricular dissociation (2) with cycles oscillating
between the limit of the VT-FVT zones; a burst is used to terminate the arrhythmia - What is your diagnosis?
The EGM shows a regular, monomorphic tachycardia, alternately detected in the
VT zone and the FVT zone; the combined counter is full, with 35 cycles classified as
TS or TF. (7/6 of 30 cycles); analysis of the last 8 cycles before diagnosis shows at
least one cycle classified as TF leading to the diagnosis of FVT; the first therapy in
the VF zone (a burst) is delivered with termination of the arrhythmia. - What is the diagnosis made by the system?
The diagnosis is that of FVT via the combined counter
Message à retenir
- This plot shows another example of how the combined counter works.
- The tachycardia oscillates between the VT zone and the FVT zone programmed
via VF; therefore the 2 VT and VF counters increment in parallel. - The combined counter has been developed to avoid delaying therapy in this
scenario. - When the combined counter is filled (35 TS or TF cycles in this example), the
device analyses the last 8 intervals; here, no cycle is classified as FS, but at least
one of the cycles is classified as TF, leading to a diagnosis of FVT.