Systolic dysfunction in heart failure is defined as HF with reduced ejection fraction (HFrEF) with EF ≤40%.

Systolic dysfunction in heart failure is defined as HF with reduced ejection fraction (HFrEF) with EF ≤40%.

• A. HF w/ mildly reduced EF 41-49%
• B. HF with reduced EF ≤40%
• C. HF w/ preserved EF ≥50%
• D. HF w/ preserved EF ≤30%

Answer: (B)

Systolic dysfunction means the heart isn’t contracting well enough to eject an adequate portion of blood with each beat. That portion is the ejection fraction (EF). When EF falls to 40% or less, we classify the heart failure phenotype as heart failure with reduced ejection fraction (HFrEF). Normal EF is generally about 50-70%, and there’s a separate category for mildly reduced EF (around 41-49%), with preserved EF typically 50% or higher, which reflects a different physiology (more related to diastolic dysfunction). The option describing preserved EF as ≤30% isn’t consistent, since preserved EF implies a relatively high EF, not a low one. Therefore, EF ≤40% correctly defines systolic dysfunction in this context.

Systolic dysfunction means the heart isn’t contracting well enough to eject an adequate portion of blood with each beat. That portion is the ejection fraction (EF). When EF falls to 40% or less, we classify the heart failure phenotype as heart failure with reduced ejection fraction (HFrEF). Normal EF is generally about 50-70%, and there’s a separate category for mildly reduced EF (around 41-49%), with preserved EF typically 50% or higher, which reflects a different physiology (more related to diastolic dysfunction). The option describing preserved EF as ≤30% isn’t consistent, since preserved EF implies a relatively high EF, not a low one. Therefore, EF ≤40% correctly defines systolic dysfunction in this context.