Physiological or pseudophysiological ECG changes in endurance-trained athletes

"Sudden cardiac death'' in seemingly healthy, active, and asymptomatic peop le has always been a tragic fact and is now occurring more frequently. Thus , the preventive detection of "subjects at risk" becomes a priority. A trad itional resting electrocardiogram can sometimes give useful indications. Fi fty-two competitive triathletes were compared with 22 control persons with similar anthropometric parameters. All subjects underwent the same noninvas ive cardiac exploration with electrocardiography, bidimensional echo-Dopple r examination, and maximal spiro-ergometric exercise tests, on a stationary bicycle as well as on a treadmill. In the triathletes we noted manifest si gns of eccentric as well as concentric left ventricular hypertrophy with ar guments for a supernormal diastolic left ventricular function, with importa nt hemodynamic adjustments and with consequences on the resting electrocard iogram. We described "ten commandments'' in evaluating the resting electroc ardiogram of healthy competitive athletes. We suspect that the occurrence o f ventricular premature beats at peak load of a maximal exercise could be t he first expression of a pathological cardiac adaptation to sports activiti es. The resting electrocardiogram can show interesting details in detecting the "subjects at risk" for problems such as possible lethal arrhythmias an d "sudden cardiac death." The analysis of the four subgroups of triathletes compels us to feel dubious about the "athletic heart syndrome" as a physio logical entity. In several cases the "athletic heart' is possibly a transit ional situation to a pathological hypertrophic and dilated cardiomyopathy.