gms | German Medical Science

Objective: It is widely known that the most prevalent cause of death in young athletes is life-threatening arrhythmia. Preparticipation screening is recommended by the ESC and aims to reduce sudden cardiac deaths. Holter monitoring providing valuable cardiologic information was used in sport during 30 years [1].

The purpose of the study was to compare the rate of ECG-disturbances in contemporary adolescents with different habitual physical activity level.

Material/Methods: 24 h ECG was recorded in 22 athletes (A) 11-18 years (mean, M+/-m, 14.8+/-0.5 yr) participating in different sport disciplines and 28 non-sportsmen (NS, 17.1+/-0.3 yr). 15 athletes (15.6+/-0.5 yr) and 24 NS (16.9+/-2.2 yr) underwent polyfunctional monitoring (ECG, BP and respiratory inductance plethysmography).

Results: Athletes needed further evaluation due to ECGs or history/symptoms (casual BP elevation, overtraining). We found no differences in height and weight between A and NS in ECG group (height 172.8+/-3.2 and 173.6+/-1.7 kg; weight 60.3+/-3.5 and 60.9+/-1.8 kg), while NS in BP group were heavier (height 174.3+/-2.0 and 179.7+/-1.8 cm; weight 67.2+/-3.4 vs 85.0+/-4.0 kg, p<0.01).

Only day and night SBP in A was lower (day 130.7+/-2.7 and 138.0+/-2.4 mm Hg, p=0.03; night 113.6+/-2.9 and 119.4+/-2.3 mm Hg, p=0.05) and apnoea/hypopnoea index (AHI) in A was smaller (5,3+/-0,7 and 9,8+/-2,0; p<0,05).

Early repolarisation was seen in the day-time in 28.5% of A and in 4.2% of NS (p<0.01), whereas no difference in the night was obtained (42.9 and 37.5%).

Premature supraventricular beats >100/24h were seen in 24.1 and 21.1%; ventricular premature beats (VPBs) – in 18.2% of A and 40.4% of NS (p<0.05).

No differences were detected in AV II degree block (18.2 vs 15.4%) and SA block (33.3 vs 18.3%, p>0.05). Transient long QT-interval (<10% of time) obtained in 36.4% of A and 17.4% of NS, short QT-interval – in 9.1 vs. 17.3% in NS. Short PQ-interval existed in 21.2% of A (WPW in 3 A) vs. 15.4% of NS.

Heart rate variability analysis revealed that power spectra of low frequency band (LF, linked to the sympathetic and vasomotor modulation) both in the day-time and night and very low frequency power (reflects slow regulatory mechanisms, e.g. the renin-angiotensin system, thermoregulation) – only in night in A was significantly bigger than in NS. Power of high frequency band (related to parasympathetic activity) did not differ.

EchoCG examinations in all A were normal except mild mitral (in 35%) and tricuspid (in 18%) valve prolapse.

Conclusion: Early repolarisation in the day-time in young athletes exists more frequently, VPBs – more seldom, day systolic BP is lower and night breathing – more regular than in sedentary adolescents. Thus, Holter ECG+BP – monitoring is a useful tool for identification resting ECG features and optimization training volume and intensity in young athletes.