title: Electrophysiological effects of the antiarrhythmic agent QX-572 in the human heart with special reference to rate-induced changes in effective refractory periods.
abstract: The antiarrhythmic agent, N,N-bis(phenylcarbamoylmethyl)dimethylammonium chloride (QX-572) 8 mg/kg body weight produced a decreased conduction time through the atrioventricular node but did not influence intra-atrial or intraventricular conduction. Effective refractory periods of the atrium, the atrioventricular conduction system, and the ventricle were shortened by the drug. The observed effects were present at the end of drug infusion but had disapnerbd 30 min later. The probable explanation is an increased sympathetic tone induced by QX-572.
mesh_terms: D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000188:drug therapy*; D001794:Blood Pressure / Q000187:drug effects; D002036:Bundle of His / Q000187:drug effects; D002219:Carbamates / Q000494:pharmacology / Q000627:therapeutic use; D006328:Cardiac Catheterization; D002986:Clinical Trials as Topic; D004562:Electrocardiography; D004566:Electrodes; D004594:Electrophysiology; D005260:Female; D006325:Heart Atria / Q000187:drug effects; D006329:Heart Conduction System / Q000187:drug effects*; D006331:Heart Diseases / Q000188:drug therapy; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000187:drug effects*; D010138:Pacemaker, Artificial; D010292:Paresthesia / Q000139:chemically induced; D000644:Quaternary Ammonium Compounds / Q000009:adverse effects / Q000627:therapeutic use*; D012032:Refractory Period, Electrophysiological / Q000187:drug effects*; D012849:Sinoatrial Node / Q000187:drug effects
chemical_list: D000889:Anti-Arrhythmia Agents; D002219:Carbamates; D000644:Quaternary Ammonium Compounds