Effect of lidocaine on right ventricular muscle refractoriness.
The effect of clinical doses of lidocaine on ventricular refractoriness was investigated in man. Effective refractory period (ERP) and functional refractory period (FRP) were determined in 11 normokalemic patients via a catheter at the right ventricular apex using programmed extra-stimuli and a ventricular electrogram recorded from the pacing catheter. No subject had recent ischemia or infarction. Measurements were repeated after clinical doses of lidocaine that produced therapeutic blood levels. Lidocaine caused no significant change in ERP or FRP during ventricular or atrial drive, or sinus rhythm with unchanged cycle length (CL). During sinus rhythm ERP/CL was unchanged. In 4 of 5 patients, lidocaine did not abolish echo phenomena observed during ventricular drive. This study demonstrates that ventricular refractoriness can be safely measured in man. Clinical doses of lidocaine did not alter right ventricular refractory periods. Lidocaine action is not explained by alteration of ventricular refractoriness, at least in muscle remote from the site of acute infarction.
D000368:Aged; D004562:Electrocardiography; D005260:Female; D006352:Heart Ventricles / Q000187:drug effects*; D006801:Humans; D008012:Lidocaine / Q000097:blood / Q000494:pharmacology*; D008297:Male; D008839:Microelectrodes; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012032:Refractory Period, Electrophysiological / Q000187:drug effects
D008012:Lidocaine