dr.atif
Forum Newbie
Topics: 4
Posts: 12
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hi all,
i was going thru ace inhibitors in lippincott pharmacology.In the chapter for congestive cardiac failure they have mentioned that ace inhibitors cause an increase in cardiac output by decreasing the preload and aftrload. but in the chapter for antihypertensive drugs they have mentioned that ace inhibitors cause a decrease in the bloob pressure by causing a decrease in peripheral resistance. this is very confusing can any one explain me what is all this? its so confusing :roll:
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| Ahab
Forum Elite
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AT II, in addition to causing the release of aldosterone will also act as a vasoconstrictor. Reduced vasoconstriction ->reduced resistance -> reduced pre and afterload.
Ace inhibitors have also been found to reverse cardiac hypertrophy, improving survival in CHF, since hypertrophy goes inwards into the heart a reversal maybe causes an increased eventual increase in stroke volume?
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| dr.atif
Forum Newbie
Topics: 4
Posts: 12
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thanks ahab
as u have said it reduces preload and afterload thereby causing an increase in the cardiac output .this is also written in lippincott and i understood that
but my point is that if cardiac output is increased then how is it gonna help in the control of blood pressure as
BP is directly proportional to CO :roll:
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| dariush
Forum Elite
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wow somewhere down the line you misunderstood something.
since when would dec. in Preload lead to inc. in CO ??!! (remember Frank-Starling law)
ACE-I does dec preload(volume:by inhib. Aldosteron--> dec. Na,H2O retention) and afterload(Arterial Resistance:by inhib. the production of AGII) which together both decrease the BP and the burden on the Failing heart in CHF although it has Not (+) ionotropic effect on the heart, it as Ahab mentioned inc. survival by dec the REMODELING of the myocardium.
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| dariush
Forum Elite
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btw i forgot to say it is also shown to be ANTI-DEPRESSIVE making it a good choice in elderly.
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