ECG screening and prevention of sudden cardiac death in endurance athletes over 40
Authors: Ricciardi D , Liporace P , Crispino E , Marchi F , Sanasi L , Loiacono G , Sposito E , Italiano E L , D'amore M C , Gioia F , Picarelli F , Calabrese V , Grigioni F , Ussia G P 
Published: May 2024

Abstract

Introduction
CV diseases increase with age. There are many athletes aged &gt;40 years who practise in certain endurance sports (marathon, ultramarathon and cycling), that involve very high intensity physical exertion and prolonged efforts. This population, like others athletes, undergo to annual examination with a medical history, spirometry, urine test and exercise test. CVdisease and sudden cardiac death (SCD) are the main cause of mortality in athletes during sport and this specific population group are at increased CV risk due to their multiple comorbidities, so this kind of screening remains controversial.

Aims
The primary aim of the study is to evaluate whether a 5-minute 'mini Holter ECG', associated with the conventional examination, can have an additional role for early screening and prevention of CV diseases in older endurance sport population.

Materials
The population were selected as part of the larger 'Heart And Run' project, an ECG collection of endurance athletes of the main sports clubs in Rome - Italy. A control group of healty individiuals was collected for comparison. The ECG traces were recorded at rest for 5 minutes with the Kardia Mobile device 6L™. HRV indices were analysed using the software Kubios. The study group were compared for an ECG morphological analysis and HRV parameters in the time and frequency domain.

Results
A total of 353 subjects (182 athletes, 171 controls) were analysed. The athlets show a significantly higher incidence of sinus arrhythmias, LAFB, 1°degree AVB, Jpoint elevation and STsegment abnormalities. We found also a significantly shorter QTc in athlets compared to controls (395.95 ± 29.51 ms vs. 411.6 ± 29.01 ms), suggestive of greater protection from malignant ventricular arrhythmias. In line with the ECG findings, the HRV PNS (-0.25 ± 1.25 vs -1.05 ± 1.45) and SNS (0.69 ± 1.44 vs 2.38 ± 1.89) indices were respectively higher and lower in the athletes group than in the controls group. Differences between the two groups were also found in the time and frequency HRV domain analysis (SDNN, RMSSD, NN50 and pNN50). Due to the absence of normality range, we considered values lower of the 5th or higher of the 95th percentile range, for the main HRV parameters, as abnormals. We identified 29/182 virtually abnormal HRV individuals. Those patients could be at increased CV risk, worthy of further investigation. In total, out-of-range HRV values or morphological abnormalities were detected in 54 athletes (29%), a population that will need further attention through follow-up and additional examinations.

Conclusions
Despite competitive endurance sports are associated with increased vagal tone, which is virtually protective against CV diseases, even in athletes over 40, the addition of the 5-minute cardiac 'mini Holter' could increase the sensitivity in detection of CV disease, in a specific high-risk group of athletes, suggesting additional clinical and instrumental investigations in such patients.