Heart Failure Overview

Heart Failure (HF)

• A clinical syndrome marked by progressive weakening of the heart's pump function
• Leads to systemic, organ, and cellular level changes
• Prevalence is increasing due to the aging population
• Leads to death from progressive loss of myocardial cells and arrhythmias

Classification

• Acute/Chronic: Depends on disease development speed

  • Acute: Often associated with a myocardial infarction (MI)

• Forward/Backward Failure:

  • Forward: Reduced blood flow throughout the body (cyanosis)
  • Backward: Congestion in the veins, leading to lung and systemic congestion

• Systolic/Diastolic Dysfunction:

  • Reduced ejection fraction (EF): Indicates poor pumping ability. Normal EF is 55-75%. Heart failure with reduced ejection fraction (HF-REF): EF <35%.
  • Diastolic dysfunction: Impaired relaxation of the heart. Heart failure with preserved ejection fraction (HF-PEF): EF 50-75%.

Left-Sided Heart Failure (Left HF)

• Backward Failure: Congestion in the left atrium and lungs
• Symptoms:
  • Pulmonary edema: Fluid buildup in the lungs, causing:
    • Pulmonary rales (crackling sounds)
    • Dyspnea (shortness of breath)
    • Orthopnea (shortness of breath when lying down)
    • Paroxysmal nocturnal dyspnea (sudden shortness of breath at night)
  • Forward Failure: Reduced blood flow (weakness, fatigue, and reduced oxygen supply)
  • Nycturia: Excessive urination at night

Right-Sided Heart Failure (Right HF)

• Results from increased pulmonary pressure, leading to backward failure
• Symptoms:
  • Edema (swelling)
  • Congestive hepatomegaly (enlarged liver)
  • Distension of neck veins
  • Cyanosis (bluish discoloration)
  • S3 gallop (third heart sound)

Provoking and Exacerbating Factors

• Underlying causes of HF:
  • Ischemic heart disease
  • Hypertension
  • Diabetes mellitus
  • Cardiomyopathies
  • Valvular heart disease
• Precipitating/exacerbating causes:
  • Volume overload (renal failure, high sodium)
  • Pressure overload (high blood pressure, pulmonary embolism)
  • Metabolic needs (fever, infection)

Diagnostic Options

• Anamnesis and physical exam
• ECG
• Biomarkers: BNP, NT-proBNP, ST2, hs-TnT
• Echocardiography: Used to measure EF.

Systolic and Diastolic Dysfunction

• Can occur simultaneously. In ischemic heart conditions, the heart muscles may not be able to contract properly, leading to systolic dysfunction. Also, the heart muscle may stiffen impeding the ventricles to properly fill up, causing diastolic dysfunction.