Drugs for Heart Failure Flashcards
Definition of heart failure.
Heart is unable to pump the blood that’s brought to it.
Heart failure leads to these 2 things:
1) Congestion
2) Edema
Congestion definition.
Blood backs up in the veins and causes them to swell, seen in the jugular vein in the neck!
Swelling of the jugular vein in the neck indicates:
Congestion from heart failure.
What causes pulmonary edema?
Left-sided heart failure.
What causes peripheral edema?
Right-sided heart failure.
2 Major causes of heart failure?
1) Chronic hypertension
2) Myocardial Infarction
Preload definition.
How much a muscle stretches before it contracts.
Frank-Starling Law
The greater the preload, the greater the heart’s force of contraction.
How does Digoxin work?
It inhibits the Na/K pump in the heart, allowing intracellular Calcium to increase, and this increases the force of the heart contraction.
Afterload definition
The force against which the ventricle ejects.
What is afterload determined by?
1) Peripheral Resistance (most important)
2) Blood viscosity
3) Blood volume in the arterial system
What is hypertension caused by?
An increase in peripheral resistance.
What is cardiac remodeling?
Structural changes in the heart to compensate for heart failure, which leads to diminished function.
Examples of cardiac remodeling.
1) Increase in heart size
2) Fibrosis
3) Shape changes
4) Cardiac output declines
First line agents to treat heart failure.
1) Diuretics
2) ACE Inhibitors and ARB’s
3) Aldosterone inhibitors
4) Beta blockers
Diuretics used to treat mild to moderate congestive heart failure.
Thiazide diuretics
Diuretics used to treat SEVERE congestive heart failure.
Loop diuretics
These diuretics counteract hypokalemia caused by other diuretics.
Potassium-sparing diuretics.
Examples of potassium-sparing diuretics:
Spironolactone, Triamterene, Amiloride
These diuretics cause HYPOkalemia.
Thiazide and loop diuretics.
Adverse effect of potassium-sparing diuretics.
HYPERkalemia.
MOA of spironolactone.
Blocks Aldosterone receptors.
Renin-Angiotensin-Aldosterone inhibitors used in the tx of heart failure.
1) ACE Inhibitors
2) ARB’s (Angiotensin Receptor Blockers)
3) Aldosterone Receptor Blockers (Spironolactone)
End in “pril.”
ACE Inhibitor
Ends in “sartan.”
Angiotensin Receptor Blocker
How do diuretics work to treat heart failure?
1) Decreased blood volume
2) Decreased pulmonary and peripheral edema
3) Decreased preload
4) Decreased afterload
5) Decreased cardiac dilation
Renin-Angiotensin-Aldosterone Inhibitors all reduce ________ _______.
Cardiac remodeling
Adverse effects of RAAS Inhibitors.
HYPERkalemia
Beta blockers protect against _______ in heart failure.
Dysrrythmias by reducing sympathetic stimulation.
Adverse effects of beta blockers.
1) Worsen heart failure
2) Bradycardia
3) Heart block
A cardiac glycoside used to treat heart failure.
Digoxin.
How does Digoxin work?
It inhibits the Na/K pump, which causes Calcium to build up inside the cell, and this increases the force of contraction.
Digoxin is considered a _________-line agent in the tx of heart failure.
second
Result of increased cardiac output from digoxin.
1) Decreased sympathetic tone.
2) Decreased Renin release
Hemodynamic effects of Digoxin
1) Preload is decreased
2) Afterload is decreased
3) Renal blood flow increases- so urine output increases
4) Edema is reduced
Cardiac adverse effects of Digoxin.
Cardiac dysryhthmias!
1) Decreased SA node (pacemaker) activity
2) Decreased AV conduction
3) Spontaneous activity of Purkinje fibers
4) Shortening of the effective refractory period of the ventricles
Digoxin is considered a positive _________ agent.
ionotropic
Ionotropic agents (other than Digoxin) used to treat heart failure.
1) Sympathomimetics
2) Phosphodiesterase inhibitors
Sympathomimetics used to treat heart failure.
Dobutamine and Dopamine
How does Dobutamine work?
Is a beta 1 receptor agonist to increase contractility and cardiac output.
How does Dopamine work?
1) Binds to Dopamine receptors in the kidney to increase renal blood flow and urine output.
2) Causes NE release to increase Beta activation of the heart.
Phosphodiesterase Inhibitors end in ________.
“Rinone”
Examples of Phosphodiesterase Inhibitors
Inamrinone
Milrinone
Isosorbide and Nesiritide are _________.
Vasodilators
