Cardiac Failure DDx


In emergency medicine and critical care, the cardiac failure that primarily concerns us is acute heart failure syndrome (AHFS), which refers to rapid worsening of heart failure signs and symptoms, and has many possible causes.

Types of acute heart failure syndrome

AHFS has 5 clinical scenarios which guide acute management:


  • Hypertensive (systolic blood pressure (SBP)>140 mmHg)
  • acute pulmonary edema
  • little or no systemic edema
  • may be hypovolemic or euvolemic


  • Normotensive (SBP 100-140 mmHg)
  • gradual onset predominant systemic oedema
  • absent or mild pulmonary edema


  • Hypotension (SBP <100 mmHg)
  • Signs of organ hypoperfusion predominate
  • End-stage cardiac failure or cardiogenic shock (ADD LINK)


  • Evidence of acute coronary syndrome (ADD LINK)
  • Symptoms and signs of acute heart failure


  • Isolated right ventricular dysfunction
  • acute or gradual onset predominant systemic oedema
  • no pulmonary edema

Causes of cardiac failure

Low output failure

  • Impaired contractility
    • Ischemia/ infarction
    • Acute mitral or aortic regurgitation
    • myocarditis
    • Cardiomyopathy, e.g. Tako-Tsubo
    • Drugs, e.g. calcium channel blockers
    • Sepsis
    • Infiltrative disorders, e.g. amyolidosis
  • Impaired filling
    • Diastolic dysfunction (e.g. hypertensive hypertrophy)
    • Mitral or tricuspid stenosis
    • Restrictive cardiomyopathy
    • Constrictive pericarditis
    • Myxoma
  • Excess afterload
    • Aortic or pulmonary stenosis
    • Hypertension
    • Pulmonary hypertension, e.g. pulmonary embolism
  • Dysrhythmias

High output failure

  • Anemia
  • Pregnancy
  • Beri beri
  • Paget’s disease
  • Hyperthyroidism
  • Arteriovenous malformations

CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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