Shortness of Breath
Sort cardiac from non-cardiac dyspnea — recognize the can’t-miss causes and act safely.
Learning Objectives
- 1.Build a differential for dyspnea spanning cardiac and non-cardiac causes.
- 2.Use history, exam, and targeted tests to localize the cause.
- 3.Recognize the dyspnea presentations that require urgent action.
Overview
Dyspnea is common and broad. The cardiology lens asks: is this heart failure, ischemia, arrhythmia, or a non-cardiac cause — and how sick is the patient right now?
Why this matters
Acute decompensated heart failure, ACS, and PE can all present primarily as dyspnea. Severity assessment and the right few tests sort them quickly.
The can’t-miss list
- •Acute decompensated heart failure / flash pulmonary edema.
- •Acute coronary syndrome (dyspnea can be an anginal equivalent).
- •Pulmonary embolism.
- •Tamponade; severe arrhythmia.
- •Non-cardiac emergencies: severe asthma/COPD, pneumonia, pneumothorax.
Focused history
- •Onset (sudden vs gradual), exertional tolerance change.
- •Orthopnea, paroxysmal nocturnal dyspnea, edema, weight gain (HF).
- •Chest pain, palpitations, syncope.
- •VTE risk factors (PE); fever/cough (infection); wheeze (airways).
Exam and data
- •Severity: can they speak in full sentences? Work of breathing? O2 sat.
- •Volume/perfusion: JVP, crackles, edema, perfusion.
- •EKG, troponin, natriuretic peptide (BNP/NT-proBNP), chest imaging; echo for structure/function.
Putting it together
- •Congestion (elevated JVP, crackles, edema) + elevated BNP → heart failure picture.
- •Sudden pleuritic dyspnea + VTE risk → evaluate for PE.
- •Dyspnea with ischemic EKG/troponin → ACS pathway.
- •Wheeze, fever, focal findings point non-cardiac.
Management & disposition
- •Stabilize first: oxygen for hypoxia, upright positioning, monitor.
- •Decompensated HF → decongestion and escalation per severity.
- •Match treatment to the cause; admit the unstable or undifferentiated-sick patient.
Red flags / escalation
- •Can’t speak in full sentences; hypoxia; accessory muscle use.
- •Dyspnea with chest pain, ischemic EKG, or hemodynamic instability.
- •Flash pulmonary edema.
Escalate immediately
Severe respiratory distress, hypoxia, or dyspnea with instability/ischemia is an emergency — stabilize and get the physician now.
Common beginner mistakes
- •Calling all dyspnea "COPD/anxiety" without assessing volume status and cardiac causes.
- •Missing dyspnea as an anginal equivalent (especially in diabetics/elderly/women).
- •Treating a BNP in isolation without the clinical picture.
Nurse / MA workflow connection
- •MA-obtained O2 sat/weight and nurse "speak-in-sentences" triage rapidly flag the sick dyspneic patient to you.
Mini cases
HF patient, 5-lb weight gain, orthopnea, bibasilar crackles, elevated JVP, O2 sat 90%.
Cause and action?
Show answer
Decompensated heart failure with congestion. Begin decongestion per protocol, oxygen, and escalate per severity; this is not a routine outpatient adjustment if hypoxic/distressed.
Post-op patient with sudden pleuritic dyspnea, tachycardia, and clear lungs.
What can’t you miss?
Show answer
Pulmonary embolism — sudden pleuritic dyspnea with a VTE risk factor (recent surgery). Pursue PE evaluation and escalate; don’t default to "anxiety."