Electrical disconnection versus anatomical isolation of the pulmonary veins: two sides of the same treatment for atrial fibrillation?
OBJECTIVE
There are currently two techniques for percutaneous electrical isolation of the pulmonary veins (PV): anatomical isolation and electrical disconnection. The aim of the present study was to assess the continuity and circumferential extension of the radiofrequency applications necessary for PV electrical disconnection in order to evaluate the differences between this technique and anatomical isolation.


METHODS
We studied 9 patients with paroxysmal atrial fibrillation who underwent PV electrical disconnection. The electrophysiologic study was performed with a decapolar circular catheter (Lasso) introduced in the PV ostia and a mapping and ablation catheter (CARTO). Ablation was performed following the activation sequence of PV potentials. Using the CARTO system we evaluated the number of applications, their distribution in quadrants, and the maximum distance between contiguous and opposite RF applications. We assessed the number of veins with circumferential applications. The number of applications and maximum distance between contiguous applications were compared to the maximum distance between opposite applications.


RESULTS
A total of 26 PV were isolated, including 9 right superior, 5 right inferior, 6 left superior and 6 left inferior.  On average more than 10 applications were necessary, with a heterogeneous distribution.  In 80.8% of the PVs the maximum distance between contiguous application was less than 1 cm and maximum distance between opposite application were highest in the right superior PV and lowest in the right inferior PV.  The applications were circumferential in 80.8% of the disconnections.  The number of RF applications was significantly higher in PVs with greater distances between opposite applications (correlation coefficient 0.51; p=0.008). No relation was found between maximum distances in contiguous and opposite applications (correlation coefficient r=0.13; p=NS).


CONCLUSIONS
Electrical disconnection was achieved in the great majority of cases with circumferential applications, similarly to anatomical isolation.  However, the heterogeneous distribution of the applications implies the existence of areas that need a greater number of applications and that can only be identified during electrophysiologic study.  Therefore, rather than two aspects of the same treatment for atrial fibrillation, electrical disconnection and anatomical isolation complement each other in the achievement of effective PV isolation.
Adragão
Pedro
P
Serviço de Cardiologia, Hospital de Santa Cruz, Carnaxide, Portugal. padragao@netcabo.pt
Reis-Santos
Katya
K
Scanavacca
Maurício
M
Cavaco
Diogo
D
Aguíar
Carlos
C
Morgado
Francisco
F
Ribeiras
Regina
R
Bernardo
Ricardo
R
Bonhorst
Daniel
D
Seabra-Gomes
Ricardo
R
D000328:Adult; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins