T wave inversion on the electrocardiogram: when to worry and when not to

Negative T waves at electrocardiogram in young healthy people are often a challenging finding for the clinical cardiologist, who should consider a normal variant of the electrocardiogram in youth, an athlete’s heart adaptation to physical activity, or an initial stage of a pathologic process such as right ventricular arrhythmogenic or hypertrophic cardiomyopathy. The differential diagnosis is crucial particularly considering the fitness credential for athletic activities. Numerous studies have been carried out trying to resolve this problem, with results not always consonant. The European Society of Cardiology suggests further investigation when negative T waves are present beyond V1, whether the Seattle criteria consider V2 the limit. Data from the literature seem to agree that anterior negative T waves have a benign connotation in pre-puberty adolescents and in African athletes. In Caucasian post-puberty people, negative T waves beyond V2 are questionable, but uncommon enough as to justify a thorough diagnostic investigation. On the other hand, negative T waves in inferior-lateral leads call for an extensive work up. T wave inversion (TWI) beyond V2 in Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is common and considered a major diagnostic criterion; on the other hand, the available studies suggest that myocardial pathology is very uncommon in people with TWI in V2–V3. This difference underscores that the data derived from the patients with ARVC lack specificity in low-risk population. In pre-puberty adolescents and African athletes TWI in the anterior leads has a benign connotation. In post-puberal Caucasians, TWI beyond V2 is of questionable significance, and rare enough (1/200 athletes), as to justify a thorough investigation, as suggested by the Seattle criteria. TWI in the inferior-lateral leads in young people requires careful investigation is warranted to rule out cardiomyopathy. A TWI in these leads could be a benign finding, but could also be the first sign of a pathologic condition not yet manifested. ‘Epsilon’ wave, prolonged terminal activation of the QRS (>55 ms), and depression of the ‘J’ point before the negative T wave are all electrocardiographic markers that increase significantly the probability of a cardiomyopathy. A careful electrocardiographic analysis should be integrated with an accurate history including: previous cardiac diseases, symptoms, family history positive for cardiomyopathy or sudden death, all of which could empower the significance of the electrocardiographic anomalies. Alternative causes of TWI in young people including substance abuse (cocaine and amphetamine), electrolytes unbalance (hypokalaemia), or long QT syndrome (particularly type 2) should be excluded. A young asymptomatic person with TWI should receive, first of all, a careful history and physical examination. When the person is after puberty and has anterior TWI beyond V2 or when the anomaly affects the inferior-lateral leads, it is reasonable to proceed with echocardiography or even magnetic resonance. The positive turn of the T waves during exercise occurs in a similar fashion in people with or without cardiomyopathy, and, as such, the test is of limited clinical usefulness. The electrocardiographic anomalies could represent the first manifestation of a subtle pathologic condition, which will become apparent at a later time, so that repeated periodic examinations are necessary. Patient’s work up immediately changes as symptoms appear. For athletes, diagnostic work up may vary according to the different manifestations: Asymptomatic athlete, TWI, and evidence of cardiomyopathy: refrain from agonistic activities; genetic testing also for the immediate family. Asymptomatic athlete, TWI, and no evidence of cardiomyopathy or positive family history: no limitation to sport activities, possible genetic testing, careful attention to symptoms occurrence, annual check-ups, possible electrocardiography, and echocardiography for the first degree relatives. Asymptomatic athlete, TWI, and uncertain evidences of cardiomyopathy and no family history: no limitation to sport activities, possible genetic testing, careful attention to symptoms occurrence, annual check-ups, possible electrocardiography, and echocardiography for the first degree relatives. Asymptomatic athlete, TWI, and uncertain evidences of cardiomyopathy and positive family history: sport activities of only low-moderate intensity, possible genetic testing, careful attention to symptoms occurrence, annual check-ups, possible electrocardiography, and echocardiography for the first-degree relatives. Conflict of interest: none declared.