HFrEF Definition
LVEF ≤ 40% (systolic dysfunction; eccentric remodeling)
GDMT Quadruplet
ARNI/ACEi + Beta-Blocker + MRA + SGLT2i (reduces all-cause mortality)
Acute Decompensation
First-line: IV Loop Diuretic (furosemide) ± Vasodilators (nitroglycerin)
Cardiovascular Reflex
Sympathetics T1–T5; Chapman point at 2nd ICS at sternal border
HFrEF vs. HFpEF Pathophysiology & Diagnosis
Heart failure is a complex clinical syndrome resulting from structural or functional impairment of ventricular filling or ejection:
| Parameter | HFrEF (Reduced Ejection Fraction) | HFpEF (Preserved Ejection Fraction) |
|---|---|---|
| Ejection Fraction | ≤ 40% (Systolic failure) | ≥ 50% (Diastolic failure) |
| Ventricular Remodeling | Eccentric hypertrophy (chamber dilation, thin walls) | Concentric hypertrophy (thick stiff walls, small cavity) |
| Primary Etiologies | Ischemic heart disease (CAD/MI), dilated cardiomyopathy | Longstanding hypertension, aging, diabetes, obesity, amyloidosis |
| Auscultation | S3 gallop (rapid ventricular filling into dilated ventricle) | S4 gallop (atrial kick against stiff, non-compliant wall) |
| Biomarkers | Markedly elevated BNP / NT-proBNP | Mild to moderately elevated BNP; diastolic dysfunction on Echo |
Guideline-Directed Medical Therapy (The 4 Pillars)
Modern GDMT quadruplet therapy provides profound cumulative survival benefits in HFrEF:
1. ARNI (Sacubitril/Valsartan) or ACEi/ARB
Inhibits neprilysin (increasing natriuretic peptides, bradykinin) and blocks AT1 receptors. Superior to enalapril in reducing cardiovascular death. Requires 36-hour washout when switching from ACEi to prevent angioedema.
2. Evidence-Based Beta-Blockers
Only 3 beta-blockers reduce mortality in HFrEF: Carvedilol, Metoprolol Succinate, and Bisoprolol. (Mnemonic: 'Beta-blockers Curb Mortality'). Initiate only when patient is euvolemic.
3. Mineralocorticoid Receptor Antagonist (MRA)
Spironolactone or Eplerenone. Decreases myocardial fibrosis. Monitor serum potassium and renal function closely (contraindicated if K+ > 5.0 mEq/L or CrCl < 30 mL/min).
4. SGLT2 Inhibitors
Dapagliflozin or Empagliflozin. Reduces HF hospitalizations and cardiovascular mortality regardless of diabetes status.
Acute Decompensated Heart Failure (Warm/Cold & Wet/Dry)
Hemodynamic classification directs emergency therapy: 'Wet' reflects congestion (elevated PCWP > 18 mmHg); 'Cold' reflects hypoperfusion (cardiac index < 2.2 L/min/m2). Warm and Wet is the most common presentation: treat with IV loop diuretics and IV vasodilators.
COMLEX / OMM Integration
NBOME High-Yield Correlate
Lymphatic Considerations in Congestive Failure
- Thoracic Duct Clearance: Treatment of the thoracic inlet (Sibson's fascia) and rib cage motion is crucial to maximize lymphatic drainage from the pulmonary interstitium.
- Contraindication: Vigorous lymphatic pump techniques are CONTRAINDICATED in severe acute uncompensated pulmonary edema due to risk of overwhelming right-heart volume capacity.
- Contraindication: Vigorous lymphatic pump techniques are CONTRAINDICATED in severe acute uncompensated pulmonary edema due to risk of overwhelming right-heart volume capacity.
Board Traps & Common Distractors
- Trap: Starting or increasing beta-blocker doses during acute decompensated heart failure with volume overload. Beta-blockers must be maintained or gently held if cardiogenic shock is present, never titrated upward in acute fluid overload.
- Trap: Adding digoxin for mortality reduction. Digoxin improves symptoms and reduces hospitalizations but does NOT decrease overall mortality in HFrEF.