[Analysis of the junctional rhythm characteristics in patients with nodal reentry tachycardia treated with slow pathway radiofrequency ablation].
OBJECTIVE
To study the quantitative and qualitative aspects of junctional rhythm (JR) during radiofrequency (RF) catheter ablation of slow pathway in atrioventricular nodal reentrant tachycardia.


METHODS
Twenty five patients, 5 males, ages ranging from 15 to 76 years, with recurrent atrioventricular nodal reentrant tachycardia, underwent to RF catheter ablation of slow pathway. During RF applications (40V, duration 60s) electrocardiographic was continuously recorded. The recordings were posteriorly used to study the presence and characteristics of JR (number of episodes, frequency and time of onset) at the effective and ineffective RF sessions. All variables were expressed as median and mean +/- SD. Univariate analysis of the effects of each variable on success or failure of ablation were performed using x2 test. A p value < 0.05 was considered significant.


RESULTS
One hundred forty nine RF sessions were performed, 25 effective and 124 ineffective (mean per patient 6, range 1 to 22). JR was present in 18 of 25 effective and 44 of 124 ineffective sessions (p < 0.05). Mean time of appearance was 12s, occurring later this time in 9 of 18 effective and in 10 of 44 ineffective sessions (p < 0.05). Mean number of episodes was 3, occurring higher number in 7 of 18 effective and in 4 of 44 ineffective sessions (p < 0.05). Median of frequency of JR was 100bpm; 11 of 18 effective and 15 of 44 ineffective sessions presented higher frequencies (p < 0.05).


CONCLUSIONS
JR during slow pathway ablation is a sensitive marker of ablation success. JR predictor of success has higher number of episodes, higher frequency and later time of appearance than that one of ineffective sessions.
Escola Paulista de Medicina, São Paulo.
A
A
Mendonça
A A
AA
de Paola
N
N
Mehta
R M
RM
Silva
E
E
Figueiredo
F A
FA
Gondim
V M
VM
Hara
M Z
MZ
Távora
E E
EE
Martinez Filho
D000293:Adolescent; D000328:Adult; D000368:Aged; D001283:Atrioventricular Node / Q000503:physiopathology*; D002036:Bundle of His / Q000503:physiopathology; D017115:Catheter Ablation; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology* / Q000601:surgery
Análise das características do ritmo juncional em pacientes com taquicardia por reentrada nodal submetidos a ablação da via lenta por radiofreqüência.