Body Surface Electrocardiographic Mapping in Athletes with Early Repolarization Syndrome of the Ventricles of the Heart

An electrocardiotopographic study during the terminal stage of excitation and the initial stage of recovery of ventricular excitability has been carried out in athletes with early ventricular repolarization syndrome (ERS) on routine electrocardiograms (ECGs). ERS is common in the “athlete’s heart” and is a characteristic feature of the functionally complete state of the myocardium of athletes, it allows to be considered a model without associated pathologies. Multiple ECG leads on the torso surface are used for detailed study of the formation of myocardial electrical activity and to access additional information not obtained in a routine ECG. The cardiac electrical activity of athletes in different sport disciplines who trained at the stage of sport improvement and the stage of higher sportsmanship was studied. Based on routine ECG, subjects were divided into groups: with signs of ERS (n = 19), with ST-segment elevation (ST is the fragment of the ECG measured between QRS complex and T-wave) without other signs of ERS (n = 14), and without ST-segment elevation and other signs of ERS (n = 14). Cardiac electrical potentials on the torso surface were recorded at rest and immediately after performing the bike ergometer test. Instantaneous body surface equipotential maps were used to assess the spatiotemporal dynamics of the regions and extremes of positive and negative cardiac potentials on the athletes' torso surface during depolarization and the initial stage of ventricular repolarization. Exercise testing revealed no adverse ECG signs and confirmed a high functional state in all athletes. It was revealed in shorter PRII, QRSII, QTc, and J-TpeakII intervals, as well as lower T-wave amplitude in leads V4 and V5 in athletes with ERS compared to participants in other groups. In athletes with ERS it was shown a specific pattern of cardiac electrical potential distribution on the torso surface during the final stage of ventricular depolarization, which is not typical for athletes with and without ST-segment elevation, against the background of the same cardiac electrical field during ventricular repolarization in all subjects. Analysis of the spatial parameters of the cardiac electric field in athletes with ERS revealed the increase of the myocardial electrical heterogeneity resulted in the overlay of depolarization of the heart base on the initial repolarization of other myocardial regions.