Congestive Heart Failure – For the USMLE exams

by / Thursday, 01 July 2010 / Published in Internal Medicine

….

Definition:

  • CHF occurs when the cardiac output is insufficient to met systemic demands
  • May be right-sided, left-sided, or both

Causes:

  • Valvular diseases
  • MI
  • Hypertension
  • PE
  • Anemia
  • Cardiomyopathy
  • Edocarditis
  • Thyrotoxicosis

Signs and Symptoms:

Left-sided:  signs and symptoms are due to ß CO and Ý cardiac pressures

  • Paroxysmal nocturnal dyspnea
  • Exertional dyspnea
  • Orthopnea
  • Cardiomegaly
  • S3 gallop
  • Renal hypoperfusion (leads to sodium retention and worsened CHF)

Right-sided:  signs and symptoms are due to pooling upstream of the right heart

  • Increased JVP
  • Edema
  • Hepatic congestion
  • Atrial fibrillation (increases risk of embolization)
  • Fatigue
  • Cyanosis
  • Weight loss

Diagnose with echocardiogram

Treatment:

  • 1st line regimen – ACEI, b-blockers, furosemide and spironolactone, and digoxin
  • If patient cannot tolerate ACEI, try hydralazine + isosorbide dinitrate

ACEIs have been proven to decrease mortality in CHF

b-blockers have been to decrease mortality

  • Don’t start b-blockers during active failure because they can exacerbate the condition
  • Start b-blockers once patient is fully diuresed and is on stable doses of other medications

Spironolactone proven to decrease mortality in class IV CHF

Loops almost always used to maintain dry weight in CHF patients

Digoxin improves symptoms but DOESN’T decrease mortality

Be wary of giving Loop diuretic without spironolactone because this can cause an unsafe hypokalemia that potentiates the effect of digoxin (1st sign of digoxin toxicity is a SVT with AV block and blurry yellow vision)

Leave a Reply

TOP