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24 Cards in this Set
- Front
- Back
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Heart Failure
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cardiac output not enough to sustain tissues
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components of heart failure
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systolic dyfxn- weak contraction
dyastolic dysfxn- stiff ventricle |
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Cardiac Output
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Stroke volume X Heart Rate
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Stroke Volume
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1)Preload- filling pressure
2)Afterload- vascular resistance 3)Contractility |
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Factors leading to decreased CO
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1)Low preload
2)High afterload 3)(-) contractility 4) low heart rate |
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Main cardiac calcium channels
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1)V-gated calcium channel
(aka L-channel: allows entrance of calcium into cardiac cell) 2)Ca+ gated calcium channel (allows calcium release from SR) |
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Neurohumoral compensation in HF
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1)SNS--> increased myocardial contractility,HR,and renin release
2)RAS activation-->increased Na+ retention and peripheral vasoconstriction |
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Frank-starling compensation in HF
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cardiac muscle stretch-->decreased contractile strength
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Main classes of drugs used in HF
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1)Afterload reduction
2)Diuresis 3)Positive inotropy 4)Beta-adrenergic blockade |
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Drugs for AFTERLOAD REDUCTION
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1)ACE (-)s
2)ARBs 3)Isordil/Hydralazine 4)alpha/calcium channel blockers |
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Drug classes that cause DIURESIS
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1)Loop diuretics
2)Spironolactones |
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Adrenergic agonists
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1)NE
2)Isoproterenol 3)Dopamine 4)Dobutamine |
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Isoproterenol
(beta 1, beta 2) |
Adrenergic agonist used for short term support to induce POSITIVE INOTROPY
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beta 1 receptor activity in
1)myocardium 2)SA node 3)AV node |
1)increase contractility
2)increase HR 3)increase conductance |
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beta 2 receptor activity in
1)arterioles 2)lung |
1)vasodilation
2)bronchodilation |
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alpha 1 receptor activity in
1)peripheral arterioles |
1)vasoconstriction
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alpha 2 receptor activity in
1)nerve terminals |
1)(-) NE release
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Epinephrine
(alpha 1, beta 1 and beta 2) |
Adrenergic agonist
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NE
(alpha 1, beta 1) |
adrenergic agonist with
1)beta 1--> inotropic, chronotropic effects (raises O2 consumption) 2) beta 2--> vasodilation 3) alpha 1-->systemic vasoconstriction and increased work load |
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Dopamine
(beta 1 and alpha 2 at high[]s |
adrenergic agonist used for short term support
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Dobutamine
(beta 1 and beta 2) |
Adrenergic agonist
Dopamine receptors not affected Inotropic Vasodilation Increases CO, but doesnt change HR and O2 consumption Used for short term (ICU) |
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phosphodiesterase inhibitors
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amrinone
milrinone |
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phosphodiesterase (-)s action
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inotropic w/o increased HR
peripheral vasodilation |
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side effects of phosphodiesterase (-)s
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Toxicity: GI, fever, thrombocytopenia
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