Prolonged QT Interval in Athletes: Distinguishing between Pathology and Physiology

Abstract

Background: The physiological QT prolongation in athletes is expected to widen the grey zone between physiology and pathology of QT, increasing the diagnostic challenges encountered in athletes with QT prolongation. Summary: According to International recommendations for electrocardiogram (ECG) in athletes, further evaluation for long QT syndrome (LQTS) is indicated in male athletes with corrected QTc≥470 ms and in female athletes with QTc≥480 ms. Apart from corrected QT (QTc)≥500 ms, diagnostic challenges arise in borderline cases of QTc prolongation, where further clinical investigations are needed to be performed to clarify whether LQTS exists. Clinical diagnostic investigations, including exercise testing, are more readily available, convenient and easily interpretable, as well as less costly than genetic testing for LQTS. The main findings on exercise testing that are suggestive of LQTS can be the paradoxical prolongation of QTc during exercise and QTc≥480 ms at fourth min of recovery. Key messages: Exercise testing appears to have an important role in the diagnostic evaluation of athletes with prolonged QT interval, when genetic testing is not available.

Cardiopulmonary examinations of athletes returning to high-intensity sport activity following SARS-CoV-2 infection

“…Detailed evaluation revealed resting or exercise-induced atrial or ventricular arrhythmias or significant ST-T changes (ST-depression, T-wave inversion) in 8 (4.8%) athletes, while no pathological resting or exercise induced corrected QT interval changes (calculated by the Bazett formula) were found in any of the athletes 25 . In these cases, no direct connection between ECG abnormalities and the infection were proven, but further evaluation and close follow-up were recommended to exclude any potentially malignant arrhythmias or cardiac pathologies.…”

“…A detailed questionnaire was implemented to record the data of SARS-CoV-2 infection and sport activity. The severity of the acute infection was classified in accordance with the recommendations of Löllgen H et al 22 Following physical examination and blood pressure measurement (Omron M6 Comfort, OMRON Healthcare Group, Japan), 12-lead ECG (CardioSoft PC, GE Healthcare, Finland) was recorded in a resting, laying position and analysed according to the current guidelines 23 – 25 . Cardiac necroenzyme levels were measured from blood samples (cobas e 411 analyzer, ROCHE Hungary Ltd, Hungary; Elecsys Troponin T hs, Roche Diagnostics International AG, Switzerland 26 ).…”

Evaluation of electrocardiographic parameters in amputee football players

“…The QTc values may change in both physiological and pathological conditions. Chronic exercise training in athletes has been associated with longer QT interval, whereas quitting exercise has been related to normalization of ECG with reappearance of repolarization abnormalities after beginning of exercise training ( Christou et al, 2022 ). QT prolongation in athletes has been linked with decreased QT dispersion and thus diminished arrhythmic potential, implying the benign nature of this physiological adaptation to chronic exercise training ( Stolt et al, 1999 ).…”

Physiological Changes in QRS Fragmentation in Athletes and Nonathletes without Cardiac Disease

“…Electrocardiographic measurements included heart rate, PR interval, QRS duration, QT interval, and QRS axis. Bazett's formula was used for calculation of corrected QT [10]. A second electrocardiogram was performed in 52 individuals (34 men and 18 women) after deep inspiration breath-hold for some seconds.…”

“…These considerations are particularly important in athletes, since the possibility of chronic exercise-related electrocardiographic patterns should always be taken into account [8]. Even more, athletic activity poses an additional risk of sudden cardiac death in individuals with concealed cardiac disease, mandating a low threshold for extensive diagnostic evaluation in case of suspicious electrocardiographic patterns [9,10].…”