Restrictive Cardiomyopathy


  • Restrictive cardiomyopathy is the least common form of cardiomyopathy.
  • It occurs in the advanced stages of myocardial infiltrative disease — e.g. due to haemochromatosis, amyloidosis or sarcoidosis.
  • Diffuse myocardial infiltration leads to low voltage QRS complexes.
  • Atrial fibrillation may occur due to atrial enlargement; ventricular arrhythmias are also common.
  • Infiltration of the cardiac conducting system (e.g. due to septal granuloma formation in sarcoidosis) may lead to conduction disturbance — e.g. bundle branch blocks and AV block.
  • Healing granulomas in sarcoidosis may produce “pseudo-infarction” Q waves.

Electrocardiographic Features

  • Low voltage QRS complexes
  • Non-specific ST segment / T wave changes
  • Bundle branch blocks
  • Atrioventricular block (3rd degree AV block may occur in sarcoidosis)
  • Pathological Q waves
  • Atrial and ventricular dysrhythmias

ECG Example

Low QRS voltage


Related Topics

Further Reading

Author Credits


  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.
  • Edhouse J, Thakur RK, Khalil JM. ABC of clinical electrocardiography. Conditions affecting the left side of the heart. BMJ. 2002 May 25;324(7348):1264-7. Review. PubMed PMID: 12028984; PubMed Central PMCID: PMC1123219 [Full Text].
  • Surawicz B, Knilans TK. Chou’s Electrocardiography in Clinical Practice. 6th Edition. Saunders Elsevier 2008.
  • Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.
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