How to differentiate between benign early repolarization, left ventricular hypertrophy (LVH) with pericarditis, and ventricular aneurysm?

Differentiating Benign Early Repolarization, LVH with Pericarditis, and Ventricular Aneurysm

The key to distinguishing these conditions lies in analyzing specific ECG patterns: PR segment deviation and ST/T ratio favor pericarditis over early repolarization, while the presence of pathological Q waves, reciprocal ST changes, and wall motion abnormalities on echocardiography distinguish ventricular aneurysm from the other two conditions. 1

Benign Early Repolarization vs Acute Pericarditis

ECG Features Favoring Pericarditis

• PR segment deviation is the most specific finding for pericarditis—it occurs in both limb and precordial leads in pericarditis, whereas in early repolarization PR deviations are confined to either lead group only 1, 2
• ST/T ratio ≥0.25 in leads I, V4, V5, or V6 strongly suggests pericarditis over early repolarization, with lead I having the best predictive value (0.82) 3
• Horizontal ST-segment vector positioned left of the T-wave vector favors pericarditis, while vertical ST-segment vector positioned right of the T-wave vector favors early repolarization 2
• ST depression in lead V1 is significantly more common in pericarditis (present in approximately 29% vs 4% in early repolarization) 2
• In lead V6, the J point >25% of T wave height (using PR segment as baseline) indicates pericarditis 1

ECG Features Favoring Early Repolarization

• Isoelectric ST segment in lead V6 strongly favors early repolarization over pericarditis 2
• J-point elevation with slurring, oscillation, or notch at the end of QRS (best seen with tall R and T waves) characterizes early repolarization 1
• Concave ST-segment elevation with peaked T waves in inferior and/or lateral leads is typical of benign early repolarization 1
• Temporal stability of ST-T patterns over time suggests benign early repolarization, whereas dynamic changes suggest pericarditis 4
• Early repolarization does not evolve through stages like pericarditis (which progresses through 4 distinct ECG stages) 1

High-Risk Early Repolarization Patterns

• Notching pattern with horizontal/descending ST segment carries increased mortality risk and may represent malignant early repolarization requiring further evaluation 5
• Convex upward J waves with "lambda-wave" ST shape suggest idiopathic ventricular fibrillation risk rather than benign variant 4
• Dynamic ST-T changes predominantly at night with J waves >2 mm amplitude suggest malignant early repolarization 4

LVH vs Pericarditis

Distinguishing Features

• Isolated voltage criteria for LVH (Sokolow-Lyon or Cornell) without additional abnormalities is common in athletes and does not suggest pathology 1
• Pathological LVH (from cardiomyopathy or hypertensive heart disease) characteristically shows voltage criteria plus one or more of: left atrial enlargement, left-axis deviation, ST-segment depression, T-wave inversion, or pathological Q waves 1
• Non-voltage criteria for LVH (ST depression, T-wave inversion in lateral leads) require echocardiography to exclude structural heart disease 1
• Pericarditis shows diffuse ST elevation in anterior and inferior leads (I, II, aVL, aVF, V3-V6) with PR segment deviations, which does not occur in LVH 1

Ventricular Aneurysm vs Early Repolarization/Pericarditis

ECG Features of Ventricular Aneurysm

• Persistent ST elevation (>20 minutes, often weeks to months after MI) in a specific coronary territory with established Q waves suggests ventricular aneurysm 1
• Pathological Q waves (Q/R ratio ≥0.25 or ≥40 ms duration) in two or more contiguous leads indicate prior transmural infarction and possible aneurysm 1
• Reciprocal ST depression in opposite leads accompanies ST elevation in ventricular aneurysm, unlike benign early repolarization 1
• ST elevation in ventricular aneurysm is typically convex or straight rather than concave 1

Diagnostic Workup Required

• Echocardiography is mandatory to identify wall motion abnormalities, thinned myocardium, and dyskinetic segments characteristic of ventricular aneurysm 1
• Cardiac MRI with gadolinium provides superior assessment and demonstrates late gadolinium enhancement indicating myocardial fibrosis/scar 1
• Prior ECG comparison is essential—new ST elevation suggests acute process (pericarditis/MI), while unchanged ST elevation suggests chronic aneurysm 1

Practical Diagnostic Algorithm

Step 1: Assess PR Segment

• PR segment deviation in multiple leads → Pericarditis 1, 2
• No PR deviation → Proceed to Step 2

Step 2: Evaluate ST Morphology and Distribution

• Concave ST elevation with J-point notching/slurring in inferior/lateral leads + stable over time → Benign early repolarization 1
• Diffuse ST elevation (anterior + inferior) with evolving stages → Pericarditis 1
• Localized ST elevation with pathological Q waves in same territory → Ventricular aneurysm 1

Step 3: Calculate ST/T Ratio in Lead I

• ST/T ratio ≥0.25 → Pericarditis 3
• ST/T ratio <0.25 → Early repolarization or aneurysm (distinguish by Q waves and chronicity) 3

Step 4: Check for Pathological Q Waves

• Present with persistent ST elevation → Ventricular aneurysm (confirm with echo) 1
• Absent → Pericarditis or early repolarization 1

Step 5: Assess Voltage Criteria for LVH

• Isolated voltage criteria without ST-T abnormalities → Physiologic LVH (no further workup if asymptomatic) 1
• Voltage criteria + ST depression/T-wave inversion → Pathological LVH (requires echocardiography) 1

Critical Pitfalls to Avoid

• Do not diagnose pericarditis without PR segment deviation—this is the most specific finding and its absence should prompt consideration of other diagnoses 1, 2
• Do not assume all ST elevation in young males is benign early repolarization—check for dynamic changes, symptoms, and troponin elevation to exclude acute coronary syndrome 1
• Do not rely on voltage criteria alone for LVH diagnosis in the presence of bundle branch block, as these patterns make voltage criteria unreliable 6
• Do not miss posterior MI—obtain posterior leads (V7-V9) when inferior ST depression is present, as 4% of acute MIs show ST elevation only in posterior leads 1
• Do not overlook high-risk early repolarization patterns—notching with horizontal ST segments carries increased mortality risk and requires cardiology consultation 5