Effects of HF

Remodeling

  • Change in chamber size, wall mass, functionality

  • In response to injury or change in load

  • Affected by neurohormonal factors

    • Eccentric - volume overload

      • Regurgitation, dilated CM, pregnancy

    • Concentric - pressure overload

      • Aortic stenosis, HTN

Heart Failure ➔ ↓ Cardiac Output

↓ CO ➔ ↑ HR ↑ contractility ↑

  • Receptors detect ↓ BP ➔ release aromatic amines ➔ ↑ HR and contractility

  • ↓ CO ➔ ↓ renal perfusion (↓ GFR) ➔ secretion of renin and activation of renin-angiotensin-aldosterone system (RAAS)

    • RAAS tries to ↑ CO by ↑ BP:

      • ↑ volume (reabsorbing salt and H2O follows)

      • vasoconstriction (↑ peripheral resistance)

    • This attempt to ↑ CO makes HF worse:

      • ↑ preload (from ↑ volume)

      • ↑ afterload (from vasoconstriction)

  • RAAS self-regulates via feedback mechanisms (BNP counteracts the activation of RAAS)