Electrocardiogram Interpretation

The American College of Cardiology considers the persistent juvenile T-wave pattern normal only up to 16 years of age, characterized by T-wave inversion or biphasic T-waves beyond lead V2 in adolescents who have not reached physical maturity 1
The prevalence of the juvenile T-wave pattern varies by age, with a presence in 10-15% of white adolescent athletes aged 12 years, decreasing to 2.5% in white athletes aged 14-15 years, and rare (0.1%) in white athletes ≥16 years or younger athletes who have completed puberty, as shown in the following table:

Population	Prevalence of T-wave inversion
White adolescent athletes at 12 years old	10-15%
White adolescent athletes at 14-15 years old	2.5%
Athletes of African or Caribbean origin	up to 25%
White athletes ≥16 years old	0.1% (beyond V2)

[1] [2]

T-wave inversion in the anterior leads (V1-V3) does not prompt further evaluation in asymptomatic patients with no signs of cardiac disease and no family history of cardiac disease, but is considered abnormal in leads V2, V3, and V4 in symptomatic patients, according to the American College of Cardiology 1
Black athletes commonly demonstrate a repolarization variant with J-point elevation, convex ST-segment elevation in anterior leads (V1-V4), and T-wave inversion, which is considered normal regardless of age, but T-wave inversion in leads other than V1-V3 is associated with a higher risk of cardiac death and arrhythmia, possibly reflecting underlying structural heart disease, as stated by the European Heart Journal [1] [2]

Abnormal Findings and Evaluation

T-wave inversion in precordial leads V2-V4 in a symptomatic patient could indicate myocardial ischemia/infarction or myocarditis/pericarditis, and requires further cardiac evaluation, including complete cardiac biomarkers, such as serial troponin measurements, and stress testing if coronary artery disease is suspected, as recommended by the American College of Cardiology [3] [1]
Echocardiography is the first-line investigation for persistence of T-wave inversion beyond age 16 years, T-wave inversion extending beyond V3, presence of symptoms or family history of cardiac disease, as recommended by the American College of Cardiology and the European Heart Journal 1, 2
Diagnostic studies such as cardiac magnetic resonance imaging or genetic testing should be performed if indications for further evaluation are met, such as age ≥16 years with persistent T-wave inversion beyond V2, T-wave inversion extending beyond V3, T-wave inversion ≥2 mm deep in two or more adjacent leads, symptoms, family history of sudden cardiac death or cardiomyopathy, or other abnormal ECG findings, as suggested by the American College of Cardiology and the European Heart Journal 1, 2

Follow-up is essential, even if initial evaluation is negative, as some pathologies may express later, and the American College of Cardiology and the European Heart Journal recommend evaluation if any of the following are present: age ≥16 years with persistent T-wave inversion beyond V2, T-wave inversion extending beyond V3, T-wave inversion ≥2 mm deep in two or more adjacent leads, symptoms, family history of sudden cardiac death or cardiomyopathy, or other abnormal ECG findings 1, 2
Comparison with prior ECGs is essential, as changes from previous tracings are particularly significant, as stated by the American College of Cardiology 3