Triggered activities in cat heart induced by combined administration of ouabain and calcium gluconate
Yu, W.G.; Xie, J.T.
Zhongguo Yao Li Xue Bao 14(3): 249-252
1993
ISSN/ISBN: 0253-9756 PMID: 8237403 Document Number: 416737
The pharmacological effects of iv a mixture of ouabain (Oua) (50 mu-g cntdot kg-1) and calcium gluconate (Ca-2+) (100 mg cntdot kg-1) on the electric activities of the cat hearts (n = 19) were studied by using a contact electrode and a contact electrode catheter to record both epicardial and endocardial monophasic action potentials (MAP). The results showed that the 2 drugs together reduced the MAP amplitude, decreased V-max, and lengthened the MAP duration. Ouabain induced triggered activities, eg, early afterdepolarization, early afterhyperpolarization, delayed afterdepolarization including oscillatory afterpotentials, and triggered arrhythmias, which were enhanced by calcium gluconate. Endocardium is more sensitive than epicardium to ouabain.