Below is an interview with CRY Consultant Cardiologist Professor Sanjay Sharma, focusing on the impact of exercise on the heart and improved guidelines for interpreting ECGs that were introduced thanks to years of CRY research.
Why is it important to understand these changes?
Recognition of these factors is important to reduce the false positive rate during ECG reporting in athletes. The original European Society of Cardiology recommendations for interpretation of the athlete’s ECG were associated with a high false positive rate because they did not allow for ethnic differences and focused mainly on leisure athletes rather than highly competitive athletes. Studies in predominantly white athletes have shown that the false positive rate with the new recommendations is less than 3%.
Why are these new international recommendations for interpreting ECGs so important?
There have been several developments in the interpretation of the athlete’s ECG since 2010 (Seattle criteria and the refined criteria) which are all incorporated in the new international recommendations. Most of the studies leading to these developments were conducted at St George’s, University of London, and funded by CRY. The international recommendations seek to provide just one set of uniform recommendations that all sports cardiologists adhere to. The paper discusses the evolution of ECG criteria and refers to the foundation set by the ESC 2010 recommendations.
What are the major changes to the way ECGs are interpreted in the new recommendations?
As opposed to just two categories – normal (type 1 patterns) and abnormal (type 2 patterns) – the current recommendations have a borderline variant category. This category has been derived from two large studies published in the European Heart Journal (EHJ) in 2014 which revealed that (1) voltage criteria for atrial enlargement of axis deviation in isolation don’t usually represent cardiac pathology in young athletes and (2) voltage criterion for right ventricular hypertrophy is common in athletes and does not equate to right ventricular pathology (Zaidi).
Based on these findings we have proposed that asymptomatic athletes with just one borderline variant do not require further investigation. Such practice has been validated in two large studies from the UK and Qatar which have shown increased specificity without compromising sensitivity. Indeed the false positive rate with the ESC 2010 recommendations was as high as 25%, but with current recommendations is expected to be less than 3%. Our own experience in the UK reveals a false positive rate of 2.5%.
How has your research into black athletes impacted the new recommendations?
The new recommendations are more specific about the normal repolarisation patterns in black athletes (anterior T-wave inversion preceded by J-point elevation and ST segment elevation). This data is also derived from the largest study in black athletes, published in the EHJ in 2010, which showed that 12% of black athletes reveal this repolarisation pattern in the absence of any overt pathology on cardiac MRI, exercise stress test and Holter. As such, these patterns are now classified as normal variants. The previous guidelines did not include the black athlete’s ECG pattern in any category.
Why is age an important part of the new recommendations?
For the first time the ECG recommendations take age into consideration and make allowances for anterior T-wave inversion (V1-V3) in athletes under 16 years old, which was absent in the 2010 recommendations. These recommendations are also derived from large cohorts of paediatric athletes and one paper was published in the EHJ.
What is a take home message for those interested in taking forward screening? How is this paper going to help them?
For the first time, the authors propose a minimum set of recommendations for investigating athletes with specific ECG abnormalities which was totally absent in the 2010 recommendations.
