Beat-to-beat QRS amplitude variability in elite endurance athletes

Results from variance electrocardiography, displaying the wide-band, phase- locked electrical micro-variability during the depolarization phase, was an alysed versus clinical data, echocardiographic structural and functional va riables and myocardial scintigraphic findings in 174 elite orienteers compa red with 37 age-matched elite endurance athletes and 50 age-matched, health y medical students. PCA analysis identified a subgroup of five orienteers d eviating from the rest of the study group and both control groups with rega rd to their QRS amplitude variability. No correlations were found between p athology by medical history or any of the echocardiographic and scintigraph ic variables or by the variance electrocardiographic aberrations in any of the groups studied.