Electrophysiological effects of melperone in the dog heart in situ - a new antiarrhythmic drug.
In pentobarbital anaesthetised dogs, melperone (a neuroleptic butyrophenone) reduced mean aortic blood pressure and at lower doses (0.5 and 2.5 mg . kg-1) increased the heart rate. By means of His bundle electrography and programmed electrical stimulation, conduction velocity and refractoriness were measured at different frequencies of stimulation (170, 200, 230 and 260 beats.min-1). Melperone 0.5 and 2.5 mg.kg-1 decreased the atrioventricular nodal conduction time and refractoriness. Melperone (0.5 to 12.5 mg.kg-1) did not affect the intra-atrial or His-Purkinje conduction times or the QRS width. However, melperone increased the functional and effective refractory period of the right atrium and ventricle dose-dependently at all frequencies studied. This suggests that melperone may be a valuable drug in treating selected cardiac arrhythmias.
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D014150:Antipsychotic Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002090:Butyrophenones / Q000494:pharmacology*; D004285:Dogs; D004558:Electric Stimulation; D004562:Electrocardiography; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006329:Heart Conduction System / Q000187:drug effects / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D008297:Male
D000889:Anti-Arrhythmia Agents; D014150:Antipsychotic Agents; D002090:Butyrophenones; C008522:metylperon