Visual Summary

Heart Failure: Pathophysiology and the Four Pillars

Module 1 — Introduction to Medical Pharmacology

Three Categories by Ejection Fraction

LVEF ≤ 40%

Reduced Ejection Fraction

  • Systolic pumping failure
  • Strongest drug evidence base
  • Four-pillar therapy applies

LVEF 41–49%

Mildly Reduced Ejection Fraction

  • Transition zone
  • Treated like reduced ejection fraction

LVEF ≥ 50%

Preserved Ejection Fraction

  • Diastolic relaxation failure
  • About half of all heart failure cases
  • Sodium-glucose cotransporter 2 inhibitors only proven class

The Neurohormonal Cascade

Trigger

Reduced cardiac output

→

Compensation

Renin-angiotensin-aldosterone system and sympathetic nervous system activation

→

Chronic Harm

Fibrosis, hypertrophy, remodeling

→

Result

Disease progression

The Four Pillars of Guideline-Directed Medical Therapy

PillarDrug ClassTargetModule
1Renin-angiotensin-aldosterone system blocker or angiotensin receptor-neprilysin inhibitorAngiotensin II / aldosteroneModule 2
2Beta-blocker (carvedilol, metoprolol succinate, bisoprolol)Sympathetic nervous systemModule 3
3Mineralocorticoid receptor antagonistAldosterone-driven fibrosisModule 4
4Sodium-glucose cotransporter 2 inhibitorMultiple cardio-metabolic pathwaysModule 5
Started together, not sequentially Each pillar independently improves survival