ABSTRACT
OBJECTIVES: To assess gender differences in training-related electrocardiographic (ECG) patterns of athletes, highlighting the importance of these differences for ECG interpretation used in the cardiovascular screening of athletes. DESIGN: Observational cross-sectional study. METHODS: 315 athletes were enrolled in the study (150 males and 165 females, mean age 23,7±6,6 and 20,7±6,8, respectively). All study participants underwent clinical examination and 12-lead electrocardiogram (12-lead ECG), scored according to 2017 International recommendations for electrocardiographic interpretation in athletes. RESULTS: Males were older (23,7±6,6 years vs. 20,7 years±6,8; p<0,0001) and had more years of training (11,8±6,7 vs. 9,07±6,1; p=0,0003) than female athletes. Female athletes had significantly higher resting heart rates (67/min vs. 61/min; p<0,0001) and QTc intervals (424,5±19,4ms vs. 338,6±22,3ms; p<0,0001). Male athletes were more likely to have isolated QRS voltage criteria for left ventricular hypertrophy (Sokolow-Lyon index) (2,6±0,8mV vs. 2,05±0,5mV; p<0,0001) and QRS duration (96,1±13,1ms vs. 86,9±9,4ms; p<0,0001). Sinus bradycardia <50bpm was more commonly seen in male athletes than in female (14% vs. 5,45%; p=0,009). Sinus arrhythmia occurred more frequently in female athletes (21,8% vs. 12,6%; p=0,03). CONCLUSIONS: This study demonstrates gender-related differences in ECGs of trained athletes that should be considered in their cardiovascular screening.
ABSTRACT
BACKGROUND AND PURPOSE: At present there are no small molecule inhibitors that show strong selectivity for the Na(+) /Ca(2+) exchanger (NCX). Hence, we studied the electrophysiological effects of acute administration of ORM-10103, a new NCX inhibitor, on the NCX and L-type Ca(2+) currents and on the formation of early and delayed afterdepolarizations. EXPERIMENTAL APPROACH: Ion currents were recorded by using a voltage clamp technique in canine single ventricular cells, and action potentials were obtained from canine and guinea pig ventricular preparations with the use of microelectrodes. KEY RESULTS: ORM-10103 significantly reduced both the inward and outward NCX currents. Even at a high concentration (10 µM), ORM-10103 did not significantly change the L-type Ca(2+) current or the maximum rate of depolarization (dV/dtmax ), indicative of the fast inward Na(+) current. At 10 µM ORM-10103 did not affect the amplitude or the dV/dtmax of the slow response action potentials recorded from guinea pig papillary muscles, which suggests it had no effect on the L-type Ca(2+) current. ORM-10103 did not influence the Na(+) /K(+) pump or the main K(+) currents of canine ventricular myocytes, except the rapid delayed rectifier K(+) current, which was slightly diminished by the drug at 3 µM. The amplitudes of pharmacologically- induced early and delayed afterdepolarizations were significantly decreased by ORM-10103 (3 and 10 µM) in a concentration-dependent manner. CONCLUSIONS AND IMPLICATIONS: ORM-10103 is a selective inhibitor of the NCX current and can abolish triggered arrhythmias. Hence, it has the potential to be used to prevent arrhythmogenic events.
