[Efficacy of sotalol in idiopathic ventricular arrhythmia originating in the right ventricular outflow tract].
OBJECTIVE
To evaluate the effects of sotalol in patients (pts) with idiopathic ventricular arrhythmias (VT) from right ventricular outflow tract.


METHODS
Eighteen pts with VT were enrolled (five with monomorphic repetitive ventricular tachycardia - MRVT). Pts were submitted to a double-blind crossover randomized study (placebo vs. 320 mg/po/d/sotalol; four weeks each), after a wash-out control period. Holter recording were recorded in control and placebo and drug periods. Eligible pts have > 50/h isolated ventricular premature beats (VPB) in control, with or without paired VPB or nonsustained VT (NSVT- > 3 beats, > 100bpm). Drug efficacy criteria was: > 75% reduction in isolated VPB and > 90% of paired VPB or NSVT. The effects of the drug on uncorrected QT interval was evaluated and also on circadian rhythm of VT through the hourly pNN50/VPB ratios. Values are given as mean +/- SD. Three recordings were compared by using paired Student's "t" test. Statistical significance was assumed for p < 0.05.


RESULTS
Differences between control and placebo were NS. Drug was effective in 61% of pts, reducing the 3 types of ET (VPB: placebo = 23.508 +/- 34.537; drug: 975 +/- 1357; paired placebo = 443 +/- 587; drug = 9 +/- 20). The drug was evaluated in 4 pts with MRVT, reducing all ectopic events, with efficacy of 60% over VPB and paired and 80% over NSVT (VPB: placebo = 52.639 +/- 42.207; drug: 1631 +/- 2062; paired: placebo = 796 +/- 754; drug: 20 +/- 30; NSVT: placebo = 4287 +/- 6343; drug: 9 +/- 11). Mean QT interval was 0.40 +/- 0.01s in control and 0.50 +/- 0.04s in the drug period, with no correlation between duration and efficacy. Sotalol modified the circadian rhythm of VPB in the non-responders group, mainly during the morning.


CONCLUSIONS
Sotalol was effective in control of VT, mainly the MRVT. Its effect on VPB circadian rhythm may independently contribute to the overall efficacy profile and myocardial protective effect of this drug.
Maia
I G
IG
Hospital Pró-Cardíaco/Pró-Ritmo/Ecor, Rio de Janeiro.
Seixas
T N
TN
Costa
A M
AM
Peres
A K
AK
Magalhães Júnior
A
A
Sá
R
R
Alves
P A
PA
D000328:Adult; D002940:Circadian Rhythm / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013015:Sotalol / Q000627:therapeutic use*; D017180:Tachycardia, Ventricular / Q000188:drug therapy*
D013015:Sotalol
Eficácia do sotalol nas arritmias ventriculares idiopáticas com origem em trato de saída de ventrículo direito.