Pathophysiology : Systolic heart failure

Pathophysiology

• Systolic heart failure
  • HFrEF – HF with reduced EF
  • Inability to pump blood forward
  • Caused by
    • Impaired contractile function
    • Increased afterload
    • Cardiomyopathy
    • Mechanical abnormalities
  • Decreased LV ejection fraction (EF)
• Diastolic heart failure
  • HFpEF – HF with preserved EF
  • Impaired ability of the ventricles to relax and fill during diastole, resulting in decreased stroke volume and CO
  • Result of left ventricular hypertrophy from hypertension, older age, female, diabetes, obesity
  • Same end result as systolic failure
• Mixed heart failure
  • Mixed systolic and diastolic failure
    • Seen in disease states such as dilated cardiomyopathy (DCM)
    • Poor EFs (<35%)
    • High pulmonary pressures
    • Biventricular failure
      • Both ventricles may be dilated and have poor filling and emptying capacity
• Right-sided heart failure
  • RV fails to pump effectively
  • Fluid backs up in venous system
  • Fluid moves into tissues and organs
  • Left-sided HF is most common cause
    • Other causes include RV infarction, PE, and cor pulmonale (RV dilation and hypertrophy)
• Heart failure
  • Ventricular failure leads to:
    • Low blood pressure (BP)
    • Low CO
    • Poor renal perfusion
  • Abrupt or subtle onset
  • Compensatory mechanisms mobilized to maintain adequate CO.