Interaction between diltiazem and enflurane in the canine blood-perfused papillary muscle and sinoatrial node preparations
Manabe, M.; Motomura, S.; Kumazawa, T.; Hashimoto, K.
Masui. Japanese Journal of Anesthesiology 36(11): 1754-1760
1987
ISSN/ISBN: 0021-4892 PMID: 3446833 Document Number: 301241
Experiments were carried out on 15 canine isolated cardiac tissue preparations perfused by blood from chronically instrumented donor dogs. Diltiazem was continuously infused i.v. into the conscious (10 dogs) and enflurane-anesthetized (1.68%, 5 dogs) donor dogs at a rate of 20 .mu.g/kg/min for 60 min. The changes induced by diltiazem were normalized by the values at the start of diltiazem infusion. (1) Decreases in blood pressure and heart rate of the conscious dog were smaller than those under anesthesia, and were also smaller than decreases in developed tension (DT) and sinoatrial rate in conscious state. (2) A decrease in DT under enflurane anesthesia was greater than that in conscious state. These results indicate that enflurane anesthesia removes the compensatory reflex present in conscious state and also increases cardiovascular effects of diltiazem.