ECG changes in Pericarditis

Synonyms: Acute pericarditis, Viral pericarditis, Infectious pericarditis

Definition: Diffuse inflammation of the pericardial lining surrounding the heart and characterized by sharp pleuritic, retrosternal chest pain worsened with recumbency and relieved by leaning forwards.

Causes of Pericarditis:

a. Infectious:

  1. Viral: Coxsackievirus, Echovirus, Ebstein-Barr virus, Influenza, HIV, Mumps virus
  2. Bacterial: Staphylococcus, Hemophilus, Pneumococcus, Salmonella, Tuberculosis, Meningococcus, Syphilis
  3. Miscellaneous: Histoplasmosis, Blastomycosis, Coccidiodomycosis, Aspergillosis, Amebiasis, Rickettsia

b. Rheumatogenic: SLE, Rheumatoid arthritis, Ankylosing spondylitis, Sarcoidosis, Scleroderma, Vasculitis

c. Neoplastic: Secondaries, Sarcomas, Mesothelioma

d. Drugs: Hydralazine, Procainamide

e. Immunologic: Celiac sprue, Inflammatory Bowel Disease

f. Other: Chest trauma, Uremia, Myxedema, Aortic dissection, Radiation therapy, Myocardial infarction, Dressler’s syndrome

g. Idiopathic

Stages of ECG changes in Pericarditis:

ECG stages pericarditis

The duration for evolution through each of the 4 ECG stages is highly variable ranging from hours to weeks. Practically, Stage I is the only diagnostic phase because Stage II looks normal and Stage III mimics ischemia.

StageECG changesElectrical basis or Mechanism
I (Everything is up)Diffuse, concave ST elevationGeneralized pericardial inflammatory process and associated myocarditis
II (Transition or pseudonormalization)ST segment returns to baselineResolution of superficial myocarditis
T-wave flattening
PR depression (ST segment appears to be elevated)Generalized epicardial atrial injury
III (Everything is down)T wave inversionDelay in repolarization of whole subepicardial healing epicardium
IV (Normalization)ECG abnormalities normalizesT wave inversions may become permanentResolution of pericarditis

Since, the secondary myocarditis is usually superficial:

  • Q waves do not form
  • R waves are unaffected
  • QRS is not prolonged
  • QT is not prolonged

Differential diagnoses:

a. Acute Myocardial Infarction (AMI):

ECG featuresAcute PericarditisAcute Myocardial Infarction
PR segment depressionCommonRare
Q-wavesAbsentPresent
St-segment elevationDiffuseConcave-upLocalizedConvex-up
Reciprocal T-wave changesAbsentOften
T-wave inversionAfter ST normalizationConcomittantly

Summary to approach:

A. Evaluate for STEMI

  1. ST depression in leads other than V1 and aVR or
  2. ST Elevation convex upwards or horizontal or
  3. ST Elevation in Lead III more than Lead II

B. Evaluate for Pericarditis (if all 3 ECG criteria above are negative)

  1. PR Segment depression in multiple leads
  2. Clinically search for pericardial rub
ST segment abnormalities
ST segment abnormalities

b. Benign Early Repolarization (BER):

ECG featuresAcute PericarditisBenign Early Repolarization
ST elevationGeneralizedLimited to precordial leads
PR depressionPresentAbsent
T wavesNormal amplitudeProminent
ST segment/T wave ratio>0.25<0.25
J-point elevation with “Fish-hook” appearance in lead V4AbsentPresent
EvolutionProgressiveStable or non-progressive

c. Others:

  1. Myocarditis
  2. Pulmonary embolism
  3. Pneumothorax
  4. Hyperkalemia
  5. Pneumopericardium
  6. Subepicardial hemorrhage

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