Circulation, Vol 76, 810-818, Copyright © 1987 by American Heart Association
LB Mitchell, DG Wyse and HJ Duff
The beta-adrenoceptor-blocking and class III effects of sotalol were
assessed in 11 patients with inducible orthodromic reciprocating
tachycardia. Serum sotalol concentration, maximum exercise heart rate, and
electrophysiologic study data were obtained at control, at the beta-
adrenoceptor-blocking dosage (407 +/- 149 mg/day, 1.4 +/- 0.5
micrograms/ml), and at the maximum well-tolerated dosage (924 +/- 337
mg/day, 3.2 +/- 1.3 micrograms/ml). Class III effects (increases in
anterograde and retrograde accessory connection effective refractory
periods, ventricular effective refractory period, and the QT interval
during fixed-rate atrial pacing) were evident at the beta-adrenoceptor-
blocking dosage of sotalol and became more marked at the maximum well-
tolerated dosage. For example, the mean anterograde accessory connection
effective refractory period was significantly increased over control (272
+/- 41 msec) by the beta-adrenoceptor blocker (324 +/- 52 msec) and was
further significantly increased by the maximum well- tolerated dose (364
+/- 37 msec). Similarly, the minimum preexcited RR interval during atrial
fibrillation was increased in all patients at each dosage tested.
Antiarrhythmic efficacy, defined by the absence of inducible, sustained,
orthodromic reciprocating tachycardia and a minimum preexcited RR interval
during atrial fibrillation of 300 msec or greater, was achieved in four
patients at the beta-adrenoceptor- blocking dosage and in another four
patients at the maximum well- tolerated dosage. These eight patients
received long-term sotalol therapy and none has had recurrent, sustained
reciprocating tachycardia during 15 +/- 12 months of follow-up.(ABSTRACT
TRUNCATED AT 250 WORDS)
ARTICLES
Electropharmacology of sotalol in patients with Wolff-Parkinson-White syndrome
Department of Medicine, Foothills General Hospital, Calgary, Alberta, Canada.
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