Frequency-dependent effects of quinidine on the ventricular action potential and QRS duration in humans.

摘要: We studied the frequency-dependent effects of quinidine on right ventricular action potential and QRS duration in 10 patients (nine men one woman; mean age, 57 +/- 14 years) undergoing electrophysiologic studies for clinical indications. The monophasic potential, electrocardiographic, conventional intracardiac electrical signals from various sites were recorded at different pacing cycle lengths 30 seconds to 1 minute before after a 10-mg/kg i.v. infusion. used extrastimulus technique determine refractory periods abrupt changes duration. progressively decreased as rate increased baseline Quinidine significantly that control by 25 msec (p less than 0.02) relatively slow 600...