• Pericardium and Pericarditis
• ECG and Acute Pericarditis
• ECG Stages of Pericarditis
• Stage 1 (First 2 Weeks)
• Stage 2 (Week 1-3)
• Stage 3 (From Week 3 Onward)
• Stage 4 (From Week 4 Onward)
• Pericarditis vs. STEMI Infarction
• Algorithm: Pericarditis vs. STEMI
• Pericarditis vs. Benign Early Repolarization
• ST/T Ratio (V6)

Pericardium and Pericarditis

• Pericardium is the membrane that encloses the heart
• It contains approximately 50ml of serous fluid
• The fluid allows for friction between the pericardium and epicardium
  
  
• Pericarditis is inflammation of the pericardium, with two types of pericarditis:
  
  
• Exudative Pericarditis
• A fluid accumulates in the pericardium due to inflammation, the heart "floats" in the fluid
• Acute Effusion
• The fluid "compresses" the heart, and the heart fails as a pump
• Tamponade can occur with as little as 200ml of effusion
• Chronic Effusion
• The effusion develops slowly, and the pericardium fills gradually
• It can contain up to 1000ml of effusion without causing tamponade
  
  
• Dry Pericarditis
• The pericardium fibroses and hardens due to inflammation
• A constrictive pericarditis may develop, where the pericardium "compresses" the heart
  
  
• 90% of acute pericarditis cases show changes on an ECG

ST Elevations and PQ Depressions

• In all leads
• Except aVR and V1

ST Depressions and PQ Elevations

• Only in aVR and V1

Spodick's Sign

• Descendent T-P segment

Pericarditis and QRS Alternans

• In exudative pericarditis, the heart "floats" in the effusion
• This causes the cardiac axis to repeatedly shift during systole
• This results in a change in the height of QRS complexes (QRS alternans)

Stage 1 (First 2 Weeks)

• Concave ST elevations and PQ depressions (in all leads except aVR and V1)
• ST elevations are most commonly 1mm (up to 5mm maximum)
• ST depressions and PQ elevations (aVR and V1)

Stage 3 (From Week 3 Onward)

• Negative T waves
• Normalized ST and PQ segments

Pericarditis vs. STEMI Infarction

• Concave ST Elevations, they are "smiling" :-)
• Pericarditis always has concave ST elevations (except aVR, V1)
• ST elevations do not correspond to the vascular supply of a single artery as in STEMI
• STEMI has convex ST elevations
• Very rarely concave
  
  
• ST Elevation (II, III)
• Pericarditis has ST elevation II > III
• STEMI may or may not have ST elevation II > III
  
  
• Reciprocal ST Depressions
• Pericarditis has ST depressions only in (aVR, V1)
• STEMI almost always has reciprocal ST depressions (opposite to ST elevations)
  
  
• Pathological Q Waves
• Pericarditis does not have pathological Q waves
• Pathological Q waves almost always occur in STEMI

Pericarditis vs. Benign Early Repolarization

• Benign Early Repolarization (BER) and pericarditis both have concave ST elevations
• BER is considered a normal variant, occurring mainly in young individuals under 50 years of age
• There is discussion about the increased risk of ventricular arrhythmias

Pericarditis

• ST elevations are present in all leads (except aVR, V1)
• PQ depressions are present in all leads (except aVR, V1)
• ST/T ratio (V6) > 0.25
• No "fishhook" (V4)
• Normal amplitude of T waves
• ECG changes gradually resolve (approximately within 4 weeks)

Benign Early Repolarization

• ST elevations are in precordial leads (V2-V6)
• No PQ depressions
• ST/T ratio (V6) < 0.25
• Presence of "fishhook" (V4)
• High amplitude of T waves (T waves are symmetrical)
• ECG changes persist for years (do not resolve within 4 weeks)

ST/T Ratio (V6)

• The ST segment/T wave ratio (V6) differentiates pericarditis from Benign Early Repolarization
• ST elevation is measured from the PQ segment (V6)
• The amplitude of the T wave is measured from the PQ segment (V6)
• Ratio(ST/T) > 0.25: Pericarditis
• Ratio(ST/T) < 0.25: Benign Early Repolarization

Pericarditis

• ST elevation = 2mm
• T wave = 4mm
• ST/T = 0.5
• ST/T > 0.25 (Pericarditis)

Benign Early Repolarization

• ST elevation = 1mm
• T wave = 6mm
• ST/T = 0.16
• ST/T < 0.25 (Benign Early Repolarization)

Benign Early Repolarization

• Concave ST elevations in precordial leads (V1-V6)
• Pericarditis has ST elevations in all leads except (aVR, V1)
• Discrete ST depression and PQ elevation only in (aVR), and not in V1
• This does not support pericarditis
• Fish hook pattern (V3, V4, III)
• Pericarditis does not have this hook
• ST/T = 0.16
• This indicates benign early repolarization
• Patient has benign early repolarization

Acute Pericarditis

• Sinus Tachycardia
• Frequency: 110/min.
• Concave ST elevations and PQ depressions in all leads except (aVR and V1)
• Absent fish hook pattern
• Patient has pericarditis (stage 1)

Acute Myopericarditis

• Concave ST elevations and PQ depressions in all leads except (aVR)
• Pericarditis should have ST depressions and PQ elevations (aVR, V1)
• No fishhook pattern present
• ST/T = 0.33
• Which indicates pericarditis
• Patient is a 6-year-old with sinus tachycardia
• Had slightly elevated cardio-specific enzymes (troponin, CK, CK-MB).
• The patient had myopericarditis (pericarditis was in stage 1)

Benign Early Repolarization

• A 23-year-old man underwent a preventive check-up
• Concave ST elevations in precordial leads (V2-V6)
• Borderline ST elevations in leads (I, II)
• Benign early repolarization (BSR) mainly shows concave ST elevations in precordial leads
• Fishhook pattern (V4-5) (indicates BSR)
• Pericarditis almost never shows this fishhook pattern
• ST/T = 0.5 (indicates pericarditis)
• Spodick's sign (indicates pericarditis)
• Descending TP segment (V5-6)
• ECG findings are not definitive for either pericarditis or BSR
• However, the patient was a young man (23 years old) without any subjective symptoms (shortness of breath, sweating, weakness, palpitations...)
• Echo and cardio-specific enzymes (troponin, CK, CK-MB) were normal
• Patient had benign early repolarization (BSR)

Acute Inferior STEMI Myocardial Infarction

• Concave ST segment (V1-6), without ST elevations, without PQ depressions
• which rules out both pericarditis and BSR
• Acute Inferior Wall Infarction (STEMI)
• ST elevations (II, III, aVF) and reciprocal ST depression (aVL)
• Pathological Q (III, aVF)
• Never occurs with pericarditis or BSR
• Unless it is an old STEMI and the patient develops pericarditis
• Patient was sweaty and had angina (chest pain)
  
  
• Algorithm for Pericarditis vs. STEMI:
1. Are ST depressions present except in (aVR and V1)?
• Yes (aVL) (patient has STEMI)