2004Nov11-Drugs-for-heart-failure.ppt

文档介绍：Drugs for heart failure
congestive heart failure


rate : output = stroke volume × HR
: (LVEDP;LVEDV)
load
Cardiac glycosides
1. Chemistry
The basicle structure of digitalis cardiac
glycosides contains:
a. aglycone whose structure is similar
to steroides ,such as adrencortical
and sex hormons .(pharmacologically
active portion of glycosides)
b. one to four sugars (solubility potency
and duration)
effects:
(1).positive inotropic effect
a. increasing the peak
force developed
D
B
A
control
C
Length of myocardial fiber
Force
b. increasing the rate of development of force and decreasing the time to peak tension
D
C
load (g)
B
A
Contraction rate
c. increasing stroke volume
(2).negative chronotropic effects :
Cardiac output blocking sympathetic
reflex and stimulating vagus heart rate
(3). Effects on the cardiac electrical activity : a. S-A node : automaticity  b. atria :ERP c. A-V node :ERP and conduction velocity d. ventricle :ERP and automaticity
S-A Atria A-V ventricles
Direct effect ERP ERP
conduct automat
indirect effect automat ERP ERP
conduct
adverse effect bradycard tachycard A-V block filbrilla
fibrilla tachycardia