Introduction
Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. Identifying non-invasive and repeatable risk markers during annual athletes screening remains a goal for the scientific community for the prevention of SCD. The Heart Rate Variability (HRV) has been shown to be an independent predictor of mortality in populations with CVD, but its relationship with SCD has been little explored in those at low risk, including athletes. This study aims to use a 5 minute ECG screening in athletes practicing endurance sports and evaluate its clinical role. The aim of the study is to assess whether morphological and spectral ECG analysis in endurance athletes by the 5-minute ECG screening can add information to periodic screening for the prevention of SCD.
Methods
The study population were selected from Endurance Marathon athletes. A control group was also collected for comparison. The 5 minutes ECG was recorded at rest with the Kardia Mobile 6L. HRV indices were obtained using the Kubios software. A morphological analysis was performed and the HRV parameters were analyzed in the time and frequency domains.
Results
A total of 554 subjects (220 athletes and 334 controls, 325 male and 229 women) were analyzed. A higher incidence of arrhythmic and morphological abnormalities in athletes compared to controls was observed (0.05). Athletes had a significantly shorter QTc than the control group, a finding suggestive of greater protection from episodes of malignant ventricular arrhythmias. Th PNS and SNS indices were respectively higher and lower in the athlete group than in the controls, suggestive for higher vagal tone. Given the absence of a normality range of standard HRV parameters in the athlete population, values in the normal range of the 5th to 95th percentile were extrapolated in the whole population for the main HRV parameters. The project, therefore, is to evaluate patients with HRV values higher or lower than 5-95 percentile to identify those deserving further clinical investigations and closer follow-up for suspected increased risk of CVD and SCD.
Conclusions
The 5-minute ECG screening allows a greater number of static and dynamic alterations to be detected; moreover, the analysis of HRV could provide more information, such that it could be considered as a complementary tool during the athlete ‘s follow-up. Further long-term prospective studies are needed to correlate alterations in HRV and clinical events.
