aconitine and Atrial-Flutter

The differential effect of different antiarrhythmic agents, quinidine, propranolol, verapamil and sotalol was studied on right- and left-sided aconitine-induced atrial arrhythmias in dogs. In control experiments the time required for the reversion of right aconitine-induced atrial arrhythmias to normal sinus rhythm was higher as compared to left-sided aconitine-induced atrial arrhythmias. All the drugs studied were effective in reverting atrial arrhythmias to normal sinus rhythm, and doses required for suppression of the right atrial arrhythmias as compared to the left atrial arrhythmias were significantly higher in the case of quinidine, sotalol and verapamil, but not in the case of propranolol. The differential antiarrhythmic effect of these drugs in atrial arrhythmias is discussed.

Topics: Aconitine; Animals; Anti-Arrhythmia Agents; Atrial Fibrillation; Atrial Flutter; Dogs; Female; Male; Propranolol; Quinidine; Sotalol; Verapamil

Topics: Aconitine; Ajmaline; Animals; Anti-Arrhythmia Agents; Atrial Fibrillation; Atrial Flutter; Blood Pressure; Dogs; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Heart Rate; Hemodynamics; Infusions, Parenteral; Vascular Resistance

The topical application of aconitine nitrate to the right atrial appendage in the "intact" anaesthetized dog produced atrial flutter. Premature systoles with fixed coupling preceded the development of flutter. In early stages of the arrhythmia, atrial rate was irregularly irregular. Also, the form of flutter beats was similar to that of preceding premature systoles. The fibrillatory activity of acetylcholine described by earlier workers has been confirmed. Transient atrial dissociation was seen after intravenous injection or topical application of acetylcholine. The occurrence of fibrillation in the left atrium after focal application of acetylcholine has been demonstrated, while the right atrial appendage containing the ectopic focus induced by aconitine continued to flutter. Aconitine produced slow-rate flutter in dogs treated with atropine or hemicholinium; this flutter was easily distinguishable from the sinus tachycardia produced by these drugs, by recording the electrocardiogram from a direct atrial lead from the area treated with aconitine, but not from limb lead II. The importance of these findings in the interpretation of the mechanism of atrial flutter and fibrillation is discussed.

Topics: Acetylcholine; Aconitine; Aconitum; Arrhythmias, Cardiac; Atrial Fibrillation; Atrial Flutter; Atropine; Brugada Syndrome; Cardiac Conduction System Disease; Dogs; Electric Stimulation; Electrocardiography; Heart Atria; Heart Conduction System; Pharmacology; Research; Toxicology; Vagus Nerve