Maurizio Lunati, Maurizio
Gasparini*, Giovanni Magenta, Giuseppe Cattafi, Rita Vecchi, Giuseppe Gadaleta.
Servizio di Elettrofisiologia ed Elettrostimolazione, Dipartimento Cardiotoracico
"A. De Gasperis", Ospedale Maggiore Cá Granda, Milano-Niguarda, *Unita
Operativa di Cardiologia, Istituto Clinico Humanitas, Rozzano, Milano, Italy
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Right ventricular tachyarrhythmias, characterized by
monomorphic left bundle branch block configuration, include three entities with different
pathophysiological substrates and clinical manifestations: 1. idiopathic ventricular
tachyarrhythmias, generally originated from the right ventricular outflow tract and
provoked by triggered activity of a specific focus; 2. ventricular tachycardias related to
arrhythmogenic right ventricular cardiomyopathy, provoked by reentry; 3. ventricular
tachycardias related to surgical repair of congenital heart disease, provoked by reentry.
Radiofrequency catheter ablation of idiopathic ventricular tachy-arrhythmias has
become a well known procedure in symptomatic patients (in over 100 patients successful
ablation was achieved in 94% with a rate of complications < 5%); experience of catheter
ablation in ventricular tachycardia due to right ventricular cardiomyopathy and surgical
repair of congenital heart disease is extremely limited and less encouraging.
Among 34 consecutive patients who presented ventricular tachy-arrhythmias with a left
bundle branch block configuration and a presumptive origin in right ventricle, referred
for electrophysiological evaluation, a catheter ablation was performed in 16 patients.
There were 9 males and 7 females; mean age was 31.3 years ± 10. In 13 patients diagnosis
of idiopathic right ventricular arrhythmias was made after complete cardiac evaluation, in
3 patients evidence of right ventricular cardiomyopathy was clear. Sites for ablation,
guided by pacemapping + endocardial activation study + response to energy applications,
were right ventricular outflow tract (anterior in 7, posterior in 5, intermediate in 1,
anterior + posterior in 2), free wall of the right ventricle (1). For patients with
idiopathic arrhythmias immediate complete success of the procedure was achieved in 11/13
(84.6%), partial success in 1/13 (7.7%), failure in 1/13 (7.7%). There were no
procedure-related complications. For patients with arrhythmias related to right
ventricular cardiomyopathy immediate complete success of the procedure was achieved in 1/3
patients (interruption of clinical ventricular tachycardia, non inducibility of other
ventricular tachycardia), partial success in 2/3 (in 1 patient 3/4 foci of inducible
ventricular tachycardia were ablated, in 1 patient 2/2 foci of inducible ventricular
tachycardia were ablated but slow non sustained ventricular tachycardia were still
inducible at the end of the sessions). In a mean follow-up of 18.5 months (range 1-40
months), in the group of patients with idiopathic tachyarrhythmias 11/13 were completely
free from any recurrence, 2 patients had an arrhythmia recurrence (after 1 month and after
7 months respectively) and a redo procedure which was effective in 1 and a failure in the
other; in patients with right ventricular cardiomyopathy 1 patient with an acute effective
result of catheter ablation had an early recurrence of ventricular tachycardia of
different morphology, had a restudy which showed inducibility of 4 different ventricular
tachycardias and was therefore treated with an ICD system, 1 patient with a partial
success of the sessions had, on drug treatment with sotalol, no recurrence of ventricular
tachycardia, 1 patient with a partial success was treated with an ICD system and drugs and
had in the following 4 months two appropriate interventions of the device. In conclusion
long term success in preventing ventricular arrhythmias is achievable with catheter
ablation in idiopathic arrhyhtmias of the right ventricle while ablative procedure in
tachyarrhythmias of right ventricular cardiomyopathy seems to be only an adjunctive and
palliative measure.
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