|
Modern implantable cardioverter-defibrillators (ICD)
present a number of ventricular antitachycardia pacing (ATP) modes. Among these the most
commonly adopted appear to be the burst, the ramp and the scan modes. Several studies
demonstrated the same efficacy and safety of these algorithms in promptly terminating
about 90% of sustained spontaneous ventricular tachycardias with a low incidence of
tachycardia acceleration. These appear to be most effective at 80-90% of the tachycardia
cycle length. Proper pre- and post-ICD implantation testing and successive reprogramming
during follow-ups are recommended to optimise the efficacy of the therapy. The efficacy of
the ATP treatment of a frequently recurrent, hemodynamically tolerated ventricular
tachycardia of two cycle lengths and of two morphologies, in a patient with arrhythmogenic
right ventricular dysplasia, who presented a sudden increase of otherwise sporadic
arrhythmic episodes, at least partially refractory to antiarrhythmic drugs, is presented.
A tiered therapy was programmed on the basis of the results of pre- and postimplantation
electrophysiological studies and of the diagnostic data stored by the implanted device
(Biotronik Phylax 06 active-can), which permitted the classification of up to four types
of tachycardia characteristics, besides those of "ventricular fibrillation". The
ATP modes terminated all the tachycardia episodes programmed to be treated, in 93% of them
at the first attempt and in respectively 6% and 1% at the second and fourth attempts. The
results obtained confirm the efficacy and safety of the ATP options, when appropriately
programmed, avoiding both physically and psychologically traumatic, unnecessary shocks,
particularly in the case of the necessity of so frequent interventions.
|
