RT-56
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Repeated IV boluses of class 1C
drugs for acute atrial fibrillation termination: a study about 135 patients
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Saverio Lavanga, Alessandro
Colombo*, Riccardo Bana, Roberto Fornerone, Franco Ferrari, Gianni Rovelli.
*Cardiology Department of Luigi Sacco Hospital, Milan, Cardiology Department of
Rho Hospital, Rho, Italy
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Abstract
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Background. To assess the efficacy of
repeated iv boluses of 1C drugs in converting acute atrial fibrillation (AF), to sinus
rhythm (SR) within 2 hrs from the beginning of treatment, we treated 140 consecutive
episodes of acute AF among 135 patients (pts).
Methods. In pts with stable acute AF, a ventricular rate response >
85 bpm and without signs of congestive heart failure, acute myocardial infarction,
arterial hypotension or clinically apparent mitral stenosis we injected either propafenone
(0.7 mg/kg of pt's body weight in 30" every 3' until a stable SR was restored or the
full dose of 2.1 mg/kg was administered) or flecainide (0.4 mg/kg in 30" every 3'
until a stable SR was restored or the full dose of 2 mg/kg was administered). Only in non
responder pts to propafenone, after 20' from the beginning of treatment, a propafenone
infusion of 7 µg/kg/min was started until the 120th minute.
Results. Conversion to SR was observed in 5 episodes (4%) after 1
bolus, in 16 (12%) after 2, in 57 (41%) after 3, in 0 after 4, in 2 (1%) after 5 boluses
and in 20 (14%) during infusion. The remaining 40 episodes had an increase in the mean RR
interval from 488 ± 66 to 616 ± 158 msec (p < 0.001). According to SR conversion pts
had the following data:
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Conversion
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No Conversion
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p
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Number of episodes
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100
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40
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-
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Arrhythmia duration (hrs)
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10.7 ± 13.4
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19.3 ± 17.3
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< 0.005
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Left atrial diameter (mm)
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38.1 ± 4.9
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42.8 ± 8.6
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< 0.005
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Conclusions. By this method, 1C drugs were effective in restoring SR
in 57% of acute AF within 20' and in 71% within 2 hrs in a median time of 12'. The success
rate was influenced by the arrhythmia duration and left atrial diameter.
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Key Words
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Atrial fibrillation
recent onset, class Ic drugs, conversion of atrial fibrillation to sinus rhythm, OA
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