Ventricular tachyarrhythmias in regional myocardial hyperkalemia: efficacy of three antiarrhythmic agents.
Potassium chloride infusion into the left anterior descending coronary artery induces a sequence of events analogous to those occurring during acute transmural ischemia. These include ST elevation, intramural conduction delay, ventricular techyarrhythmias and fibrillation. The influence of antiarrhythmic agents in an intact anesthetized canine model have not previously been tested. We have evaluated the efficacy of lidocaine, procaine amide and practolol in animals during regional hyperkalemia. In the untreated, only 9% survided a 20 minute observation period. All three treatment groups exhibited a reduced incidence of tachycardia and 74% survived the test period. In each treatment group this was associated with a further prolongation of intramural conduction time in the affected wall. This antiarrhythmic efficacy, thought possibly to be due to transformation of unidirectional to bidirectional block, supports the view that modulation of transcellular potassium activity contributes to the control of ischemic arrhythmias.
D000818:Animals; D003327:Coronary Disease / Q000378:metabolism* / Q000503:physiopathology; D004195:Disease Models, Animal; D004285:Dogs; D004562:Electrocardiography; D006329:Heart Conduction System / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000503:physiopathology; D008012:Lidocaine / Q000627:therapeutic use*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D011217:Practolol / Q000627:therapeutic use*; D011342:Procainamide / Q000627:therapeutic use*; D013610:Tachycardia / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D014693:Ventricular Fibrillation / Q000517:prevention & control
D011189:Potassium Chloride; D008012:Lidocaine; D011342:Procainamide; D011188:Potassium; D011217:Practolol