Roy Shephard’s article in the May edition of CJSM , ‘Is Electrocardiogram Screening of North American Athletes Now Warranted?’ discusses the ongoing controversy of the appropriateness of the use of ECGs in screening College athletes for causes of sudden cardiac death. I’m wondering if it is now the time for us to focus our thoughts on ECG screening of the older athletic population.
My own awareness of the issues around ECG screening of athletes started some 20 years ago when I presented a session on ‘The Athlete’s Heart’ as part of my Physiology degree studies at University College, London. I remember being quizzed at the end of my presentation by the Course Tutor on the effects of detraining, and wishing that I had done a little more reading to back up my claims when I gave my answer stating that, as the adaptations to the normal heart were the result of normal physiological mechanisms, detraining should always result in changes to pre-training baseline on the ECG reflecting the anatomical and physiological detraining effects. His face at the time told me the story that he wasn’t entirely convinced, but I think I got away with it!
I have continued to revisit the issues and re-evaluate the evidence as my career in Sport and Exercise Medicine (SEM) has progressed. My first clinical experience of preparticipation screening came almost a decade ago whilst working in New Zealand when I was involved in providing care for New Zealand Academy of Sport athletes. Since then, another essay on the subject during my MSc SEM studies, teaching MSc and BSc students on an annual basis on ‘The Athlete’s Heart and Sudden Cardiac Death,’ and most recently conducting screening as part of the Football Association’s mandatory screening programme of young footballers, has kept me in touch with emerging research and clinical practice.
One thought has remained with me over the years – that of the importance of fundamental epidemiological principles such as Wilson’s criteria in screening, and linked to those, the need to consider what we are trying to achieve by screening . Essentially, the cardiac screening process seeks to identify individuals at an increased risk of sudden cardiac death. What we do not wish to do is to prevent healthy individuals from enjoying all of the benefits of sport and exercise. Sudden Cardiac Death in the young is still a rare event, mainly due to the underlying age-related population prevalence of associated conditions such as hypertrophic cardiomyopathy, but what about the older population?
The emerging importance of physical activity as an important, under-recognised independent risk factor for morbidity and mortality, often associated with lifestyle diseases such as type II diabetes mellitus, has led to an increasing global effort to engage the population in regular exercise as part of both primary and secondary disease prevention strategies. Whilst it is indisputable that the population benefits of exercise far outweigh the associated risks, it is nevertheless true that the risk of sudden cardiac death during exercise in the over 35’s is considerably higher than in the younger population due to the higher prevalence of associated conditions, mainly coronary heart disease.
ACSM guidelines and AHA risk stratification criteria for exercise testing and prescription offer clinicians guidance in the risk stratification of individuals who engage with healthcare professionals prior to becoming physically active, and point towards the appropriate use of ECG and Exercise Stress Testing as part of the preparticipation evaluation process. However, many individuals, including the older population who regularly exercise or those who may be about to commence regular exercise having been sedentary, will not come under the care of a healthcare professional. These individuals are therefore unlikely to participate in cardiac screening programmes.
Many questions about population cardiac screening prior to participation in sport and exercise come to mind, including :
1) What is the risk / benefit ratio and cost effectiveness of the adoption of ECG screening and exercise stress testing as per ACSM and AHA guidelines on a population basis for those wishing to engage in exercise?
2) How regularly should ECG screening and cardiac stress testing as part of preparticipation evaluation on an ongoing basis be conducted in the older athletic population?
3) What is the best and most appropriate way to engage older individuals involved in exercising, or about to become physically active, in order to conduct screening?
4) Should we be adopting targeted screening including ECG and cardiac stress testing in the older population who are involved in regular exercise?
My greatest concern is for the safety of the older, sedentary individual who decides to take up the sport they previously played perhaps 20 years ago at College, or perhaps who wishes to participate in a 10K run for a local charity, and who does not seek appropriate healthcare advice prior to increasing their physical activity levels.
Should we be focussing our efforts more at population level on screening these older individuals when attempting to prevent sudden cardiac death related to exercise?