Management of chf

MANAGEMENT OF CHF


MANAGEMENT OF CHF

  • Aim of treatment for compensated/chronic CHF:
    • Decreasing work of heart – By decreasing preload & afterload.
    • Decreasing mortality – By reversing cardiac remodeling.
  • Major drugs used: Vasodilators, ACE inhibitors, ARBs, beta blockers & aldosterone antagonists.

1. Vasodilators:

MOA:

  • Acts by reducing preload (venodilators), afterload (arteriolar dilators) or both (combined arteriolar & venodilators).

Important drugs:

  • Nitrates: 
    • Preferentially dilate veins (venodilator) & reduces preload.
  • Hydralazine & minoxidil:
    • Primarily arteriolar dilators (arteriolar dilators) & reduces afterload.
    • Preferred in forward failure with low cardiac index (central venous pressure).

Note:  Calcium channel blockers contraindicated in CHF – Due to reflex sympathetic activation (nifedipine) & direct cardio-depressant action (verapamil & diltiazem) –> increasing mortality.

  • ACE inhibitors, angiotensin 2 receptor blockers (ARBs), nitroprusside & alpha blockers:
    • Reduces both preload & afterload
  • ACE inhibitors & angiotensin receptor blockers (ARBs):
    • Indicated for all CHF grades unless contraindicated specifically.
    • Decreases mortality – 
      • By prevention & reversal of cardiac remodeling due to decreased aldosterone activation (final mediator for remodeling).
  • Combination of hydralazine & isosorbide dinitrate:
    • Decreases mortality.
    • Other vasodilators do not prolong survival in CHF.

2. Aldosterone antagonists:

  • Mainly potassium-sparing diuretics – Spironolactone & epleronone.
  • Reduces mortality (at doses lower than diuretic doses) – By antagonizing aldosterone effect(reversal of remodeling). Tolerance prevented by adding thiazides.

3. Beta-blockers:

  • Contra-indicated due to their negative ionotropic action – Needs careful usage.
  • Important drugs: 
    • Carvedilol (most commonly used) –>metoprolol → bisoprolol.
  • Drug effects:
    • Increases longevity of CHF patients.
    • Causes renin release stimulating RAAS & increased aldosterone.
    • Antagonizes RAAS pathway → Causing reversal of remodeling.
  • Indication: 
    • Mild to moderate heart failure (NYHA class II & III) with dilated cardiomyopathy.
  • Contraindication: 
    • Absolutely in decompensated heart failure – As it reduces cardiac contractility.
    • Started at very low doses à gradually increased for maximum benefit.

4. Ivabradine:

  • Funny current blocker used in angina pectoris.
  • European guidelines recommend for CHF patients with heart rate >70 bpm with ejection fraction < 35%, symptomatic despite treatment with beta blockers, ACE inhibitors & aldosterone antagonists.
  • Not FDA approved for this indication.
  • Decreases myocardial oxygen demand by causing bradycardia.

5. Vasopeptidase inhibitors:

  • MOA: Inhibits two enzymes, ACE & NEP.
  • Drugs included: Omapatrilat & sampatrilat.
  • Drug effects: 
    • Possess all ACE inhibitors effects.
    • Causes natriuresis – Due to increased BNP & decreased metabolism by NEP inhibition.
  • Use: Oral treatment of chronic CHF.
  • Adverse effect: Angioedema (major).

Exam Important

  • Beta blockers are contra-indicated in CHF due to their negative ionotropic action & need careful usage.
  • Beta-blockers increases longevity of CHF patients.
  • Beta-blockers are absolutely contraindicated in decompensated heart failure, as it reduces cardiac contractility.
  • Aldosterone antagonists mainly potassium-sparing diuretics like spironolactone & eplerenone are useful in CHF.
  • Aldosterone antagonists reduce mortality (at doses lower than diuretic doses) – By antagonizing aldosterone effect(reversal of remodeling). Tolerance prevented by adding thiazides.
  • ACE inhibitors, angiotensin 2 receptor blockers (ARBs), nitroprusside & alpha blockers all reduces both preload & afterload.
  • ACE inhibitors & angiotensin receptor blockers (ARBs) indicated for all CHF grades unless contraindicated specifically.
  • ACE inhibitors & angiotensin receptor blockers (ARBs) decreases mortality.
  • Combination of hydralazine & isosorbide dinitrate decreases mortality in CHF patients.
  • Nitrates preferentially dilate veins (venodilator) & reduce preload.
  • Hydralazine & minoxidil are Primarily arteriolar dilators (arteriolar dilators) & reduces afterload.
  • Aim of treatment for compensated/chronic CHF is to decreasing work of heart – By decreasing preload & afterload & decreasing mortality – By reversing cardiac remodeling.

 

Don’t Forget to Solve all the previous Year Question asked on MANAGEMENT OF CHF

Module Below Start Quiz

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this:
Malcare WordPress Security