Response to flecainide infusion predicts long-term success of hybrid pharmacologic and ablation therapy in patients with atrial fibrillation.
OBJECTIVE
We tested the hypothesis that the response to flecainide infusion can identify patients with atrial fibrillation (AF) in whom the hybrid pharmacologic and ablation therapy reduces the recurrences of AF.


BACKGROUND
Infusion of class IC anti-arrhythmic drugs may promote transformation of AF into atrial flutter. Catheter ablation of atrial flutter has been demonstrated to be highly effective in preventing recurrences of atrial flutter.


METHODS
Seventy-one consecutive patients with paroxysmal or chronic AF, in whom flecainide infusion (2 mg/kg body weight, intravenously) determined the transformation of AF into common atrial flutter (positive response), were randomized to receive one of the following treatments: oral pharmacologic treatment with flecainide (group A, n = 23); the hybrid treatment (catheter ablation of the inferior vena cava-tricuspid annulus isthmus, plus oral flecainide) (group B, n = 24); or catheter ablation of the isthmus only (group C, n = 24). Thirty-seven patients with a negative response to flecainide, who chose to be submitted to the hybrid treatment, were selected as the control group (group D).


RESULTS
During a mean follow-up period of 24 +/- 7.2 months, the recurrences of AF and atrial flutter in group B (42%) were significantly lower than those in group A (78%, p < 0.001), group C (92%, p < 0.001) and group D (92%, p < 0.001).


CONCLUSIONS
The creation of a complete bi-directional conduction block at the inferior vena cava-tricuspid annulus isthmus, plus flecainide administration, reduces the recurrences of both AF and atrial flutter in patients with class IC atrial flutter. Moreover, the early response to flecainide is safe and reliable in identifying patients who may benefit from this therapy.
Stabile
G
G
Laboratorio di Elettrofisiologia, Casa di Cura San Michele, Maddaloni, Italy. gmrstabile@tin.it
De Simone
A
A
Turco
P
P
La Rocca
V
V
Nocerino
P
P
Astarita
C
C
Maresca
F
F
De Matteis
C
C
Di Napoli
T
T
Stabile
E
E
Vitale
D F
DF
D000284:Administration, Oral; D000368:Aged; D000704:Analysis of Variance; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D001282:Atrial Flutter / Q000209:etiology; D017115:Catheter Ablation / Q000379:methods; D002908:Chronic Disease; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D004562:Electrocardiography; D005260:Female; D005424:Flecainide / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012008:Recurrence; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D005424:Flecainide