1. Core Typology & Risk Factors

• HFrEF (Systolic): EF < 40%. LV is dilated/hypertrophied, unable to eject blood effectively, reducing CO.
• HFpEF (Diastolic): EF ≥ 50%. LV is stiff, noncompliant, causing high filling pressures and decreased filling volume.
• Causes: HTN and CAD are primary. Long-term HTN control reduces HF incidence by 50%.

2. Pathophysiology: The Compensation Trap

• Trigger: Myocardial injury -> decreased CO.
• Cascade:
  1. RAAS: Renal hypoperfusion triggers renin release, converting angiotensinogen to Angiotensin I, then Angiotensin II (vasoconstrictor). This stimulates water/sodium retention (via aldosterone/ADH) and myocardial fibr ...