ISSN:
1438-8359
Keywords:
Anesthetics
;
Halothane
;
Atrioventricular conduction
;
Verapamil
;
Diltiazem
;
Nifedipine
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The effects of halothane on AV nodal function were evaluated in dogs with verapamil, diltiazem, or nifedipine during atrial pacing using the technique of Hisbundle electrocardiography. Fifty-one mongrel dogs were divided into six groups. Anesthesia was induced with ketamine 100 mg im. and thiamylal 25 mg/kg iv. The animals were intubated and mechanically ventilated at normocapneic levels. Anesthesia was maintained with 50% nitrous-oxide in oxygen with pancuronium 2 mg im. Dogs in groups I, III, and V were anesthetized with 0.8% halothane and 50% nitrous-oxide in oxygen. We observed interactions between halothane and intravenous administration of either verapamil 0.1 mg/kg, diltiazem 0.15 mg/kg, or nifedipine 0.01 mg/kg respectively. Dogs in groups II, IV, and VI were administered either verapamil, diltiazem, or nifedipine iv without halothane. There were prolongations of sinus cycle length (SCL) (414 ± 10 to 542 ± 19 msec.), atrium-His (AH) interval (73 ± 3 to 97 ± 5 msec.), and functional refractory period (FRP) of the AV-node (227 ± 5 to 260 ± 5 msec.) in halothane anesthesia in groups I, III, and V. There were more prolongations of these variables after iv administration of verapamil (SCL; 617 ± 35, AH; 118 ± 7, FRP of the AV node; 311 ± 4) and diltiazem (SCL; 554 ± 19, AH; 118 ± 12, FRP of the AV node; 283 ± 12) but no prolongations after nifedipine (SCL; 533 ± 19, AH; 99 ± 8, FRP of the AV node; 272 ± 9). Comparing effects of calcium entry blockers with and without halothane in groups I and II, III and IV, or V and VI, there were additive depressing effects of halothane with either verapamil or diltiazem on AV nodal function. And there is a difference between the effects of nifedipine on SCL with and without halothane. (Yokota S, Harada K, Takigawa C et al.: Effects of halothane and calcium entry blockers on atrioventricular conduction; A comparative study of verapamil, diltiazem, and nifedipine. J Anesth 2: 219–226, 1998)
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s0054080020219
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