Measuring Ejection Fraction — the Splitting Criterion
Echocardiographic EF separates heart failure into distinct phenotypes.
- ≥55%: Normal EF (placeholder reference range)
- <40%: HFrEF cutoff (placeholder threshold)
- 40–49%: HFmrEF range (placeholder threshold)
- ≥50%: HFpEF cutoff (placeholder threshold)
How EF is measured
Placeholder: EF is estimated via echo Simpson biplane method.
HFrEF — The Dilated, Weakly Contracting Ventricle
Chamber dilation and reduced contractility define systolic failure.
- Dilated: Chamber size (placeholder finding)
- Thin: Wall thickness (placeholder finding)
- Reduced: Contractility (placeholder finding)
- Ischemic: Common cause (placeholder etiology)
Mechanism of systolic failure
Placeholder: remodeling and dilation reduce stroke volume output.
HFpEF — The Stiff, Poorly Filling Ventricle
Concentric hypertrophy and stiffness impair diastolic filling.
- Normal/small: Chamber size (placeholder finding)
- Thick: Wall thickness (placeholder finding)
- Impaired: Relaxation (placeholder finding)
- Hypertension: Common cause (placeholder etiology)
Mechanism of diastolic failure
Placeholder: stiff myocardium raises filling pressures despite normal EF.
Diagnostic Criteria — HFrEF vs HFpEF
Diagnosis blends EF cutoffs, biomarkers, and structural imaging.
- Elevated both: BNP/NT-proBNP (placeholder biomarker)
- Echo + E/e': Key imaging (placeholder criterion)
- H2FPEF: HFpEF score (placeholder tool)
- MAGGIC: HFrEF score (placeholder tool)
Differentiating work-up
Placeholder: combines EF, natriuretic peptides, and diastolic indices.
Treatment Approach — Diverging Therapy Pathways
Evidence-based GDMT is robust in HFrEF, limited in HFpEF.
- 4 pillars: HFrEF GDMT (placeholder regimen)
- SGLT2i: HFpEF mainstay (placeholder regimen)
- Both groups: Diuretics (placeholder use)
- HFrEF > HFpEF: Mortality benefit (placeholder outcome)
Therapy selection logic
Placeholder: drug classes chosen based on EF and comorbidities.
Placeholder key insight: phenotype determines evidence-based therapy choice.