Open AccessAntiarrhythmic and proarrhythmic properties of diazepam demonstrated by electrophysiological study in humans
Author(s) -
Kumagai Koichiro,
Yamanouchi Yoshio,
Matsuo Kunihiro,
Tashiro Noritami,
Hiroki Tadayuki,
Arakawa Kikuo
Publication year - 1991
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.4960140507
Subject(s) - medicine , diazepam , refractory period , effective refractory period , anesthesia , atrioventricular node , qrs complex , cardiology , electrophysiology , ventricle , atrium (architecture) , tachycardia , atrial fibrillation
We evaluated the electrophysiological parameters before and after the intravenous infusion of diazepam (0.2 mg/kg) in 20 cardiac patients to investigate the drug's antiarrhythmic effect. Diazepam did not significantly change the arterial pressure. After the intravenous infusion of diazepam, the sinus cycle length significantly shortened from 847±132 to 747±155 ms (p>0.01). No significant change in the maximal sinus node recovery time was noted. The AH interval at the atrial pacing length of 600 ms shortened significantly from 140±40 to 127±39 ms (p>0.05). However, there was no significant change after the administration of diazepam in the longest atrial pacing rate associated with Wenckebach conduction in the atrioventricular (AV) node, effective and functional refractory periods of the AV node, HV interval, and QRS width during ventricular pacing at the cycle length of 600 ms. The atrial and ventricular effective refractory periods remained unchanged after the administration of diazepam. Six of the eight patients who showed dual AV nodal refractory period curves in the control study did not demonstrate them after diazepam administration by increasing the atrial or AV node effective refractory period. Thus, diazepam showed significant electrophysiological effects of the heart including shortening of the sinus cycle length, improvement in AV node conduction, and no significant effect on the His‐Purkinje or intraventricular conduction and refractoriness of the atrium, AV node and ventricle. On the other hand, diazepam may influence the inducibility of supraventricular reentrant tachycardia incorporating the AV node.