[Electrophysiologic effects of intravenous flecainide in intranodal junctional tachycardia in 30 patients].
The electrophysiological effects of flecainide acetate were studied in 30 patients (10 men, 20 women, mean age 48.3 +/- 18 years) suffering from sustained re-entrant intranodal tachycardia. A 2 mg/kg dose of flecainide administered over 10 minutes was given after the onset of sustained tachycardia within 3.8 +/- 2.3 min in 25 of the 30 patients; this was effected by a block in the retrograde leg of the circuit in 22 patients and by a block in the anterograde leg in 3 patients. In the remaining 5 patients the tachycardia was slowed down (367 +/- 27 ms vs 431 +/- 48 ms) chiefly by prolongation of the atrioventricular anterograde conduction. No significant side-effect was observed while the drug was being injected. Following treatment with flecainide, tachycardia was no longer inducible in 24 out of 30 patients (A) and it remained inducible in 6 patients (B, non-responders). The initial electrophysiological exploration revealed differences between these two groups in retrograde conduction: prolongation of the ventriculoatrial time during incremental ventricular stimulation (A: 41 +/- 32 ms vs B: 81 +/- 142 ms, p less than 0.05) and prolongation of the atrioventricular time above 100 ms (A: 2/24 patients, B: 3/6 patients, p less than 0.01). The following electrophysiological parameters were significantly (p less than 0.01) ,modified after intravenous flecainide: AH and HV conduction intervals, atrial refractory periods, anterograde and retrograde atrioventricular conduction. Complete retrograde block was observed in 12 patients of group A. Thus, in this study flecainide arrested a reciprocal intranodal rhythm in 25 out of 30 patients and prevented the reinduction of tachycardia in 24 of these.(ABSTRACT TRUNCATED AT 250 WORDS)
Haissaguerre
M
M
Service de cardiologie, hôpital Saint-André, Bordeaux.
Warin
J F
JF
Goldrach
S
S
Le Métayer
P
P
Guillem
J P
JP
Blanchot
P
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D005424:Flecainide / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D006329:Heart Conduction System / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D013617:Tachycardia, Supraventricular / Q000188:drug therapy*
D005424:Flecainide
Les effets électrophysiologiques du flécaïnide intraveineux dans les tachycardies jonctionnelles intranodales chez trente patients.