Dehydrobenzperidol and disopyramide in A-V conduction.

The effects on A-V conduction of dehydrobenzperidol (Droperidol) 0.35 and 1.0 mg/kg i.v.) and disopyramide (1, 5 and 10 mg/kg i.v.) were tested in anesthetized, open chest and paced dogs. His's bundle electrograms were recorded by means of a catheter electrode or by a sutured electrode-bearing plaque in the A-V nodal region. Droperidol at the lower dose did not modify conduction time, while 1.0 mg/kg (3 times the usual clinical dose), prolonged atrial-His conduction without modifying H-V interval. Disopyramide 1 mg/kg caused a non-significant decrease in atrial-His concuction time, while in doses of 5 and 10 mg/kg it prolonged both conduction times (S-H and H-V), due to a predominant direct depressant effect, which is opposite to the atropinic actions of the drug.