H. Paydak et al., ATRIAL-FIBRILLATION AFTER RADIOFREQUENCY ABLATION OF TYPE-I AERIAL FLUTTER - TIME TO ONSET, DETERMINANTS, AND CLINICAL COURSE, Circulation, 98(4), 1998, pp. 315-322
Citations number
38
Categorie Soggetti
Peripheal Vascular Diseas",Hematology,"Cardiac & Cardiovascular System
Background-The occurrence of atrial fibrillation after ablation of typ
e I atrial nutter remains an important clinical problem. To gain furth
er insight into the pathogenesis and significance of postablation atri
al fibrillation, we examined the time to onset, determinants, and clin
ical course of atrial fibrillation after ablation of type I nutter in
a large patient cohort. Methods and Results-Of 110 consecutive patient
s with ablation of type I atrial nutter, atrial fibrillation was docum
ented in 28 (25%) during a mean follow-up of 20.1+/-9.2 months (cumula
tive probability oi 12% at 1 month, 23% at 1 year, and 30% at 2 years)
. Among 17 clinical and procedural variables,only a history of spontan
eous atrial fibrillation (relative risk 3.9, 95% confidence intervals
1.8 to 8.8, P=0.001) and left ventricular ejection fraction <50% (rela
tive risk 3.8, 95% confidence intervals 1.7 to 8.5, P=0.001) were sign
ificant and independent predictors of subsequent atrial fibrillation.
The presence of both these characteristics identified a high-risk grou
p with a 74% occurrence of atrial fibrillation. Patients with only 1 o
f these characteristics were at intermediate risk (20%), and those wit
h neither characteristic were at lowest risk (10%). The determinants a
nd clinical course of atrial fibrillation did not differ between an ea
rly (less than or equal to 1 month) compared with a later onset. Atria
l fibrillation was persistent and recurrent, requiring long-term thera
py in 18 patients, including 12 of 19 (63%) with prior atrial fibrilla
tion and left ventricular dysfunction, Conclusions-Atrial fibrillation
after type I nutter ablation is primarily determined by the presence
of a preexisting structural and electrophysiological substrate. These
data should be considered in planning postablation management. The per
sistent risk of atrial fibrillation in this population also suggests a
potentially important role for atrial fibrillation as a trigger rathe
r than a consequence of type I atrial flutter.