HFrEF vs HFpEF: what matters at the bedside
EF alone does not define the whole heart failure picture. HFrEF tends to behave more like a forward-output problem; HFpEF tends to behave more like a filling and congestion problem.
EF is an important starting point, but it does not capture the full circulatory picture. HFrEF and HFpEF present differently — in the OR and in the ICU. Separating 'not enough forward output' from 'cannot tolerate filling' helps you find the right next step faster.
Why EF alone is not enough
- A low EF does not mean the patient is actively decompensating — compensation can maintain apparent stability
- A preserved EF does not mean filling pressure or congestion is not a problem
- EF describes systolic contraction fraction, not forward flow, filling pressure, reserve, or congestion
- In the OR and ICU, the problem is often limited reserve rather than resting instability
- Mixing up a filling problem with a forward-flow problem leads to the wrong intervention
Instead of asking 'is EF high or low?', ask: 'what is the dominant problem right now?'
A simple bedside framework
Two categories — imperfect, but a useful starting point.
HFrEF (reduced EF)
Forward output and reserve are the dominant problem. Think of it as 'not getting enough out'. Induction-related vasodilation may expose how little reserve exists.
HFpEF (preserved EF)
Filling, stiffness, and congestion are the dominant problems. Think of it as 'can't accept more'. Tachycardia and fluid loading can cause rapid deterioration.
Reality: overlap is common
Real patients often do not fit neatly into one category. What matters is identifying which problem is dominant right now.
HFrEF vs HFpEF side by side
Feature
HFrEF
HFpEF
HFrEF
Forward output and reserve
HFpEF
Filling pressure, stiffness, congestion
HFrEF
Low CO, low VTI, hypotension, fatigue
HFpEF
Dyspnea, edema, tachycardia intolerance, falling SpO₂
HFrEF
LVEF, CO, LVOT VTI, MR, LV cavity size
HFpEF
E/e', LAVI, TR velocity, LA burden, pulmonary congestion
HFrEF
Vasodilation at induction may expose limited reserve. Prepare vasopressors early.
HFpEF
Tachycardia and fluid loading can rapidly worsen filling pressure and congestion.
HFrEF
Do not use low EF alone to define the whole clinical picture
HFpEF
Do not use preserved EF alone to judge safety or fluid tolerance
Common mistakes
- ✕HFpEF is a classic reason not to let a normal EF reassure you too quickly
- ✕In HFrEF, a low EF does not explain everything by itself — identify what is driving instability now
- ✕Do not use EF alone to estimate fluid tolerance or congestion risk
- ✕Do not confuse a filling problem with a forward-flow problem
- ✕HFrEF and HFpEF often overlap — focus on what is dominant right now, not just the label
How to use this perioperatively and in critical care
For HFrEF patients (induction, OR)
Vasodilation may expose limited forward reserve. Prepare vasopressors early and consider arterial line before induction. Assess CO and LVOT VTI.
For HFpEF patients (OR, ICU)
Tachycardia and fluid loading can rapidly worsen filling pressure. Watch E/e', LAVI, and SpO₂ trend. Respond early to congestion signs.
In critical care
Separate 'not enough forward output' from 'cannot tolerate filling'. Both can coexist, but the dominant problem drives the next intervention.
In either case
Combine CO, LVOT VTI, E/e', LAVI, and RV findings. EF alone is not enough to guide management.
Instead of asking 'is EF high or low?', ask: 'is this mainly a forward problem, a filling problem, or both?' That question points toward the right intervention.
Quick cases
Three scenarios — HFrEF, HFpEF, and the common mixed reality.
LVEF 32%, LVOT VTI 11 cm, CO 2.5 L/min
Forward reserve is the dominant issue. Induction vasodilation carries real hypotension risk.
Prepare vasopressors and arterial line early. Assess forward flow before loading with fluids.
LVEF 58%, E/e' 17, LAVI 40 mL/m², HR trending 90s
Elevated filling pressure and congestion burden are dominant. EF looks preserved, but reserve is low.
Do not be reassured by the preserved EF. Tachycardia and fluid loading can cause rapid deterioration.
LVEF 40%, E/e' 15, LAVI 36 mL/m², moderate MR
Forward problem and filling problem coexist. Neither alone explains the full picture.
Use CO, VTI, and E/e' together to identify which is dominant right now. That drives the next step.
Related learning
Related topics
- Fluid responsiveness and congestion tolerance are different questions
- Severe MR: perioperative management
- How to read and use LVOT VTI
- Right heart failure and venous congestion (coming soon)