Long-term Holter ECG monitoring of athletes

The purpose of the study was to detect the frequency and quality of rhythm disturbances in athletes during the late recovery period following a training session. Thirty-two athletes volunteered to participate. The ECG tracing was recorded by the use of a one-channel 12-h portable electrocardiograph cassette recorder. All subjects were instructed to keep a diary of symptoms and activities, and to record the onset of sleep and waking time. The tapes were analyzed using a rapid scanner with digital circuit for arrhythmia detection. Samples of all arrhythmic events were recorded for further analysis. The data from fitness testing, PWC170 and VO2max were higher than the mean values for active people of the same age group. The most common feature observed in our subjects, as expected, was sinus bradycardia. Most (91%) had a mild or pronounced sinus respiratory arrhythmia. Isolated atrial or ventricular premature contractions were observed in 6.2% of the subjects, intermittent first degree A-V block and second degree A-V block with Wenckebach periods were observed in 3.1%, high T-waves were found in 43.5%, and high take-off of ST segments were found in 53%. No symptoms, such as chest pain or palpitation, were recorded. The average heart rate when awake or asleep, including the longest RR interval, did not differ from the results of healthy individuals. The arrhythmias observed in our athletes were fewer than those reported in a normal population.