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CCRNHigh-YieldCardiovascular 13%
know your EF cutoffs and when to give what

Heart Failure (Systolic and Diastolic)

≤40%

HFrEF

Systolic heart failure EF cutoff

≥50%

HFpEF

Diastolic heart failure EF cutoff

4

NYHA Classes

Functional classification I through IV

HFrEF vs HFpEF

two very different problems with the same symptoms

HFrEF (EF ≤40%)

Systolic Dysfunction

  • Weak contractility, dilated ventricle
  • S3 gallop (volume overload sound)
  • Responds to GDMT (ACEi/ARB/ARNI, BB, MRA, SGLT2i)
  • Eccentric hypertrophy pattern

HFpEF (EF ≥50%)

Diastolic Dysfunction

  • Stiff ventricle, impaired relaxation
  • S4 gallop (stiff ventricle sound)
  • Diuretics, BP control, treat comorbidities
  • Concentric hypertrophy pattern

Guideline-Directed Medical Therapy

ACEi/ARB/ARNI Reduce afterload, prevent remodeling. ARNI (sacubitril/valsartan) superior to ACEi alone

Beta-Blockers Reduce HR, prevent remodeling. ONLY carvedilol or metoprolol succinate

MRA Block aldosterone, reduce fibrosis. Spironolactone or eplerenone, watch K+

SGLT2 Inhibitors Reduce preload, cardioprotective. Dapagliflozin, empagliflozin, benefit even without diabetes

Cold-wet profile (low CO, high PAOP) is the most dangerous and requires inotropes for contractility support plus diuretics for decongestion.

Key Values to Memorize

HFrEF EF ≤40%

HFpEF EF ≥50%

BNP >400 pg/mL (HF likely)

NYHA I = asymptomatic

NYHA IV = symptoms at rest

Target HR 60-70 on BB

you know the pathophysiology, now prove it under pressure

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Exam Traps

ACEi contraindicated in bilateral renal artery stenosis

Both kidneys depend on angiotensin II to maintain GFR when renal arteries are stenosed. Blocking that with an ACEi can cause acute kidney injury. The exam will pair renal artery stenosis with an ACEi order and ask you to intervene.

Monitor K+ closely with ACEi plus MRA combination

Both ACE inhibitors and mineralocorticoid receptor antagonists (spironolactone, eplerenone) raise potassium. Together they create significant hyperkalemia risk. The exam expects you to identify this drug interaction.

Only carvedilol and metoprolol succinate are evidence-based for HF

Not all beta-blockers reduce mortality in heart failure. Atenolol, metoprolol tartrate, and propranolol do NOT have the evidence. The exam will offer a wrong beta-blocker as a distractor.

Cold-wet profile requires inotropes plus diuretics

A patient with low cardiac output AND volume overload (cold and wet) is in the most dangerous hemodynamic profile. They need contractility support AND decongestion simultaneously.

Beta-Blocker Specificity

Not all beta-blockers work for heart failure. Only carvedilol and metoprolol succinate have the evidence. The exam WILL test this.

Four Hemodynamic Profiles

Warm-wet = diuretics. Cold-wet = inotropes + diuretics. Cold-dry = careful fluids. Warm-dry = optimized, no acute intervention.

1
HFrEF (Weak Pump)

Imagine a water pump that has lost its strength. It can still fill up with water, but when it squeezes, it barely pushes anything out. The ejection fraction is low because the squeeze is weak. Treatment focuses on helping the pump squeeze better and reducing the workload.

2
HFpEF (Stiff Pump)

Now imagine a pump that squeezes just fine, but its walls have become thick and stiff. It cannot relax enough to fill properly. The EF looks normal because it ejects a good percentage of what little gets in, but the total output is still reduced.

3
The Four Profiles

Think of two axes. Warm vs cold (is the pump pushing enough?). Wet vs dry (is fluid backing up?). Cold-wet is the worst because the pump is weak AND fluid is everywhere. Warm-dry is the goal.

rEF = reduced = weak pump. pEF = preserved = stiff pump.
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Reviewed by Maya P., PrepSolution Content Editor, Critical Care Nursing
Sources verified against AACN 2026 standards
Updated May 2026