Safety and efficacy of oral flecainide therapy in patients with atrioventricular re-entrant tachycardia.
OBJECTIVE
To assess the short- and long-term safety and efficacy of oral flecainide therapy in patients with symptomatic tachycardia and an extranodal accessory pathway.


METHODS
Open-label, uncontrolled trial with a mean follow-up of 24 months.


METHODS
Referral-based, teaching medical center.


METHODS
Sixty-three patients with symptomatic tachycardia and an extranodal accessory pathway.


METHODS
Patients had electrophysiologic testing before and after the initiation of oral flecainide therapy and were followed long-term for the presence of symptoms, new physical limitations, and adverse effects of therapy.


RESULTS
Flecainide therapy prevented or slowed (324 +/- 59 ms to 398 +/- 55 ms; P less than 0.001) inducible sustained atrioventricular reciprocating tachycardia in 44 of 63 patients (70%). Of the 44 patients discharged from the hospital, 33 (75%) have continued to receive flecainide therapy and have shown no adverse effects (mean follow-up, 24 +/- 10 months). Adverse cardiac reactions (proarrhythmia or sinus node suppression) attributable to flecainide occurred in 11 of 63 patients (17%); in 9 (82%) of these 11 patients, events were detected during either in-hospital monitoring or the electrophysiologic study done before discharge. Structural heart disease was detected by two-dimensional echocardiography in 8 of 11 patients who had adverse cardiac events and in 6 of 52 patients who did not have such events (P less than 0.001). Isoproterenol reversed the effects of flecainide therapy in 11 of 21 patients; 7 of the 11 patients had spontaneous clinical recurrences of tachycardia or palpitations during the follow-up period, but these symptoms occurred in only 1 of 10 patients who did not show isoproterenol-induced reversal (P = 0.02).


CONCLUSIONS
Oral flecainide therapy was effective in 33 of 63 patients who had tachycardia and an extranodal accessory connection. Hospital monitoring during initial therapy is recommended, and flecainide should be used with caution, if at all, in patients with structural heart disease. An isoproterenol challenge appears to be helpful in predicting late recurrence of tachycardia.
Cockrell
J L
JL
Letterman Army Medical Center, Presidio of San Francisco, California.
Scheinman
M M
MM
Titus
C
C
Helmy
I
I
Langberg
J J
JJ
Lee
M A
MA
Griffin
J C
JC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D002648:Child; D004558:Electric Stimulation; D005260:Female; D005424:Flecainide / Q000009:adverse effects / Q000037:antagonists & inhibitors / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000139:chemically induced; D006801:Humans; D007545:Isoproterenol; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000188:drug therapy* / Q000503:physiopathology
D005424:Flecainide; D007545:Isoproterenol