Comparative investigations on the antiarrhythmic and electrophysiologic effects of class I-IV antiarrhythmic agents following acute coronary artery occlusion.
The effects of class I to IV antiarrhythmic drugs on ventricular arrhythmias, particularly ventricular fibrillation, in relation to epicardial conduction delay during acute myocardial ischaemia were investigated in 40 open-chest anaesthetized dogs. In these animals transient coronary artery occlusion lasting 20 minutes was performed. Sixteen dogs served as controls; four groups of 6 dogs each received lidocaine (2 mg kg-1 + 50 micrograms kg-1 over 20 minutes), metoprolol (2 mg kg-1 i.v.), d-sotalol (5 mg kg-1 i.v.) and verapamil (0.25 mg kg-1 i.v.), respectively 5 minutes prior to coronary occlusion. Epicardial conduction delay was assessed by means of an epicardial mapping electrode array consisting of 42 bipolar electrodes. In the control group conduction delay displayed a bimodal time course in the ischaemic area with a maximum of 38 +/- 10 ms 6 minutes after coronary occlusion followed by a partial improvement after 12 to 15 minutes. After pretreatment with lidocaine the peak conduction delay in the ischaemic area was significantly increased (43.2 +/- 12), whereas metropolol (21.5 +/- 1.9), d-sotalol (16.6 +/- 3.7) and verapamil (16.3 +/- 3.1) significantly reduced conduction delay. Correspondingly, ventricular arrhythmias and fibrillation were almost completely prevented by metoprolol, d-sotalol or verapamil, but increased by lidocaine.(ABSTRACT TRUNCATED AT 250 WORDS)
Med. Klinik Münster, Abt. Innere Medizin C, Münster, F.R.G.
J
J
Thale
W
W
Haverkamp
G
G
Hindricks
H
H
Gülker
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D003327:Coronary Disease / Q000503:physiopathology*; D004285:Dogs; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D008790:Metoprolol / Q000494:pharmacology; D009203:Myocardial Infarction / Q000473:pathology; D013015:Sotalol / Q000494:pharmacology; D014693:Ventricular Fibrillation / Q000503:physiopathology*; D014700:Verapamil / Q000494:pharmacology
D000889:Anti-Arrhythmia Agents; D008012:Lidocaine; D013015:Sotalol; D014700:Verapamil; D008790:Metoprolol