Novel ventricular tachyarrhythmia detection enhancement detects undertreated life-threatening arrhythmias

Inappropriate ventricular fibrillation annotation and defibrillator discharge despite the same tachycardia cycle length in ventricular tachycardia‐1 zone in an Abbott defibrillator – What is the mechanism?

“…In this way VFTA overcomes the limitation of rare but real cases of life‐threatening VF / polymorphic VT under sensing. It was developed on the basis of the Merlin.net database 1 . VFTA transitions arrhythmia detection to a single zone with a slower rate cut‐off (adding 100 ms to the slowest programmed therapy zone to a maximum of 400 ms), increases the number of binned sinus intervals required to terminate the episode from five to seven, and skips further ATP and delivers direct HV (High voltage) shock therapy.…”

“…These adjusted parameters are not programmable but are based on the programmed detection and therapy parameter values and remain in effect until the device determines that the ongoing episode has terminated. Wilkoff et al 1 . found that VFTA delivered HV therapy to 0.22% (44/20,000) of the devices that experienced at least one potentially undertreated ventricular tachyarrhythmia episode.…”

Implantable Cardioverter Defibrillator Tachycardia Therapies: Past, Present and Future Directions

“…A prospective autopsy study of sudden deaths showed that 6.4% of ICD deaths occurred due to failure of VF therapy [ 154 ]. Using simulation on recorded VA intracardiac electrograms (EGMs), a novel algorithm was able to diagnose 81.9% of otherwise underdiagnosed cases of VAs [ 155 ]. This small but significant group of patients represents a blind spot and more study is needed to guide optimal management.…”

Real-world use of a novel ventricular tachyarrhythmia detection algorithm: A case report

“…The functioning of the VFTA algorithm has been described in an earlier publication. 8 It bases discrimination on 2 undersensing criteria: (1) 2 consecutive low-amplitude R waves (<0.6 mV); and (2) long R-R intervals on the far-field sensing channel (>2 seconds). Individual counters are increased when a low-amplitude R wave or long R-R interval is detected and are fulfilled when they are greater than a threshold.…”

“…The VFTA algorithm has been evaluated retrospectively on 564,353 recorded ventricular tachycardia arrhythmia electrograms from 20,000 devices, and it would have led to a new or earlier HVT in 0.27% (53/20,000) of devices with an increase of inappropriate HVT in 0.07% (14/20,000) devices 8 ; however, to our knowledge, VFTA has not yet been evaluated in prospective clinical trials. One case report 9 described VFTA activation leading to HVT in a monomorphic ventricular tachycardia episode that would has not been treated without VFTA because the arrhythmia rate was lower than the treatment zone cutoffs.…”