Drugs for Heart Failure

1
Drugs for Heart Failure

• Chapter 16

2
Circulatory System

• Blood returns from body to Right Atrium of heart
  by veins
• Flows into Right Ventricle, then to lungs to be
  oxygenated
• Flows back to Left Atrium, then Left Ventricle
• Leaves heart through aorta (largest artery in
  body)
• Arteries carry oxygen-rich blood to tissues
• Veins bring oxygen-deprived blood back to heart
  for re-oxygenation

3
Heart Failure

• Defined as weakening of heart muscle
• Blood backs up
• Usually the result of a myocardial infarction or
  longstanding hypertension
• Preload- amount of blood in veins
• Afterload (peripheral resistance)- pressure in
  arteries that must be overcome in order for heart
  to eject blood
• Contractility- strength of heart contraction
• Left sided heart failure- blood backs up into
  lungs? cough, shortness of breath
• Right sided heart failure- blood backs up in
  feet, ankles, liver? swelling

4
Non-pharmacologic therapy for Heart Failure

• Tobacco cessation
• Decrease sodium intake
• Decrease alcohol intake
• Exercise
• Decrease weight if needed
• Decrease caffeine

5
Drugs for Heart Failure

• Cardiac Glycosides
• ACE inhibitors
• Vasodilators
• Diuretics
• Beta blockers

6
Cardiac Glycosides (digoxin)

• Increase heart contractility (positive inotropic
  effect) and decrease rate
• Assess apical pulse for a full minute before
  administering (hold for lt60 bpm)
• SE change in hearts beating patterns,
  especially in clients with low potassium levels
  (monitor digoxin and potassium levels closely)

7
ACE Inhibitors (enalapril)

• Reduce peripheral resistance (decrease afterload)
• Reduce blood volume (decrease preload and
  afterload)
• See ch. 15

8
Vasodilators (hydralazine)

• Dilate veins (reduce preload) and arteries
  (reduce afterload)
• This includes coronary arteries, which allows for
  increased flow into heart muscle itself
• Some are contraindicated with sildenafil
  (Viagra), which is also a vasodilator the
  combination can cause massive hypotension

9
Diuretics (hydrochlorothiazide)

• Decrease blood volume (decrease preload and
  afterload)
• SE drop in potassium levels (use caution in
  clients on digoxin)

10
Beta Blockers (atenolol)

• Decrease heart rate, thereby reducing blood
  pressure (reduce afterload)
• Nonselective beta blockers also cause
  bronchoconstriction- remember to be cautious with
  asthmatics