Last reviewed: 1 Jun 2022
Last updated: 06 Jul 2021



History and exam

Key diagnostic factors

  • presence of risk factors
  • viral syndrome (prior)
  • autoimmune disease
  • infectious disease
  • drugs and toxins
More key diagnostic factors

Other diagnostic factors

  • age <50 years
  • chest pain
  • dyspnoea
  • orthopnoea
  • fatigue
  • palpitations
  • rales
  • elevated neck veins
  • S3 gallop
  • sinus tachycardia
  • atrial and ventricular arrhythmias
  • syncope
  • S3 and S4 summation gallop
  • pericardial friction rub
  • peripheral hypoperfusion
  • hypotension
  • altered sensorium
  • lymphadenopathy
Other diagnostic factors

Risk factors

  • infection (non-HIV)
  • HIV infection
  • smallpox vaccination
  • autoimmune/immune-mediated diseases
  • peripartum and postnatal periods
  • drugs and toxins
More risk factors

Diagnostic investigations

1st investigations to order

  • 12-lead ECG
  • CXR
  • serum CK
  • serum CK-MB
  • serum troponin (I or T)
  • serum B-type natriuretic peptide
  • two-dimensional echocardiogram
More 1st investigations to order

Investigations to consider

  • endomyocardial biopsy (EMB)
  • coronary angiography
  • cardiac MRI
More investigations to consider

Emerging tests

  • MRI-guided EMB

Treatment algorithm


haemodynamically stable: no evidence of left ventricular systolic dysfunction

haemodynamically stable: evidence of left ventricular systolic dysfunction

haemodynamically unstable


end-stage heart failure or refractory life-threatening arrhythmias



Katherine C. Wu, MD, FACC

Associate Professor of Medicine

Johns Hopkins University

School of Medicine




KCW declares that she has no competing interests.


Dr Katherine Wu would like to gratefully acknowledge Dr James E. Harvey and Dr Arman T. Askari, previous contributors to this topic. JEH and ATA declare that they have no competing interests.

Peer reviewers

David A. Leaf, MD, MPH

Professor of Medicine

School of Medicine

VA Greater Los Angeles Healthcare System


Los Angeles



DAL declares that he has no competing interests.

John Charpie, MD, PhD

Associate Professor of Pediatrics

Medical Director

Pediatric Cardiothoracic Intensive Care Unit

University of Michigan Congenital Heart Center

Ann Arbor



JC declares that he has no competing interests.

Lokesh Tejwani, MD, FACC

Assistant Professor of Clinical Medicine

University of Missouri Hospitals and Clinics

Harry S. Truman VA Hospital




LT declares that he has no competing interests.

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