Key Concepts
Introduction
Heart failure (HF) is a clinical syndrome in which the heart cannot pump enough blood to meet the body's metabolic demands, or can only do so at abnormally elevated filling pressures. It is one of the most common reasons for hospitalization in adults over 65 and a top-tested topic on NCLEX-RN. HF is classified by the side of the heart affected — left-sided (most common), right-sided, or biventricular — and by ejection fraction: HFrEF (reduced, EF < 40%), HFmrEF (mildly reduced, EF 40–49%), or HFpEF (preserved, EF ≥ 50%). Understanding the ejection fraction distinction is critical because it drives pharmacologic management. For the NCLEX-RN and US nursing practice, the priority is to recognize deterioration early, apply monitoring skills correctly, and use clinical judgment to sequence interventions in the right order. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or role, reread that line; scope errors are classic trap answers even when the clinical topic is familiar. Run a 60-second scan: breathing work and oxygenation, perfusion and...