HEART FAILURE DRUGS Flashcards
What is congestive heart failure ?
it is a pathophysiological state in which the heart fails to pump blood at a rate equal to requirements by metabolising tissue
What does CHF cause
inadequate circulation ,fluid build up in lungs , reduced oxygenation of tissues
What is the systolic failure pathophysiolgy in chf?
reduced myocardial contractility , reduced Sv ,
Increased Ventricular pressure and residual blood volume
dilated ventricles
What is the diastolic failure pathophysiology ?
ventricular relaxation reduces and ventricular filling decreases
Drug for increased Preload caused by Na+ and H20 retention?
Diuretics
Drugs for increased preload caused by vasoconstriction
Venodilators
increased afterload drugs caused by arterial vasoconstriction ?
Arterial vasodilators
What is the pathophysiology response by kidney in chf
retains water and na
maintains sv
allows the heart to function at high end diastolic volumes because of extra cellular fluid volume
Pathophyiology of CHF
edema
increased wall stress
increased pulmonary congestion causing fluid build up
end diastolic volume leads to higher end diastolic filling
increased ventricular size
What cycle follows after heart damage / ventricular overload / decreased ventricular contraction ?
- tachycardia ,ventricular dilation , myocardial hypertrophy
- reduced CO
- reduced renal perfusion
- increased sodium retention and h20
5 .increased osmotic pressure
6 increased AdH
7 .increased h20 absorption
8 .fluid overload causimg edema
Class I ambulatory treatment
diuretics
Class II ambulatory treatment
aceis/arbs
class III ambulatory treatment
diuretics + aceis/arbs
class IV ambulatory
diurectics + aceis/arbs +digoxin
what do we use instead of aceis for pts intolerable
hydralazine/nitrates
For hospitalised chf what drugs do we use with their classes in order ?
- Diuretics , pref loop diuretics
- Vasodilators , sodium nitroprusside
3.sympathomimetics = dobutamine or dopamine - phosphodiesterase inhibitors amrinone
MOA for vasodilators eg sodium nitroprusside
reduce preload and afterload
both veno and arterial dilators
inotropes moa
increase CO
ACEIs MOA
reduce vasoconstriction and and sodium and water retention
diurectics moa
Reduce sodium & water retention
reduce preload
does not reduce mortality
use minimal dose to maintain euvolemia
control congestive symptoms
Loop Diurectics examples and bio availabilty
furosemide 40-70%
.bumetanide 80%
torsemide 80%
ethacrynic acid for people allerrgic to sulfonamides
Loop diuretics moa
inhibit the Na+K+CL- symporter in the ascending loop of henle