Effeccts antiarrhythmic drug changrolin on myocardial contractility in anesthetized dogs
Abstract
An in infusion of changrolin 1 mg/kg/min was given to 6 anesthetized dogs for 20 min. The dP/dtmax, Vpm, Vmax and LVSP significantly decreased and the P-R interval of ECG prolonged at 5 min. The reduction of all these parameters was most obvious at 20 min. After the cessation of changrolin infusion these indices restored to control level.
The concentrations of changrolin in plasma at 5, 10, and 20 min after iv administration were 6.7+/-0.7, 9.4+/-0.5 and 12.9+/-0.8 microg/ml, the depression % of Vpm were 20+/-3, 32+/-4 and 50+/-7, and the prolongation % of P-R interval were 15+/-4, 35+/-5 and 51+/-10, respectively. Both the relationship between plasma changrolin concentration and depression % of Vpm (r=0.86, P<0.01), and the relationship between plasma changrolin concentration and prolongation % of P-R interval were linear (r=0.78, P<0.01).
This paper showed that iv infusion of changrolin had certain depressive effects on myocardial contractility, but this depression was reversible.
Keywords:
The concentrations of changrolin in plasma at 5, 10, and 20 min after iv administration were 6.7+/-0.7, 9.4+/-0.5 and 12.9+/-0.8 microg/ml, the depression % of Vpm were 20+/-3, 32+/-4 and 50+/-7, and the prolongation % of P-R interval were 15+/-4, 35+/-5 and 51+/-10, respectively. Both the relationship between plasma changrolin concentration and depression % of Vpm (r=0.86, P<0.01), and the relationship between plasma changrolin concentration and prolongation % of P-R interval were linear (r=0.78, P<0.01).
This paper showed that iv infusion of changrolin had certain depressive effects on myocardial contractility, but this depression was reversible.