Former CRY Research Fellow, Dr Navin Chandra, had the article ‘Sudden Cardiac Death in Young Athletes: Practical Challenges and Diagnostic Dilemmas’ published in the Journal of the American College of Cardiology (March 2013). [Full text here]
CRY Communications Officer, Mair Shepherd, caught up with him to find out more about the research behind this article.
- What was the paper about?
The article was published as a ‘state-of-the-art paper’ which basically means it’s a review article written by experts in a particular area so that they can provide their own insight and experience on a given area of cardiology.
The main aims of the article were to provide detailed information on sudden cardiac death in young athletes. We focussed on the most common conditions and how to identify them – ranging from how they present in terms of their symptoms to how to use different tools to investigate and diagnose them.
One of the main points of the article was also to aid in differentiating normal physiological changes in the structure and function of the heart in athletes, from the kind of changes you find in pathological problems of the heart which can lead to sudden cardiac death.
We focussed particularly on the overlap between changes caused by conditions called hypertrophic cardiomyopathy (HCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC), and changes you get in ‘normal’ athletes.
We also focussed part of the paper on black athletes. The reason we did this is that we found from research we’ve done through CRY that black athletes do have more abnormal ECG and Echo findings compared to white athletes. The overlap with heart conditions capable of causing sudden cardiac death is certainly wider in black athletes compared to white athletes.
As such, the article provides practical guidance for cardiologists or sports physicians on how to interpret the different changes you find; and how you would go about investigating these individuals further to get a true answer one way or the other as to whether an individual has an abnormality or whether they are just showing physiological changes due to exercise.
- How did you carry out the research?
We reviewed published articles to find out more about how conditions are diagnosed and how screening programmes are used – particularly in Europe and in America where they do have slightly different techniques for identifying these kinds of heart problems.
Through Professor Sharma’s work and the team at St George’s we’ve got quite a big cohort of athletes that have been screened for conditions that can potentially cause sudden cardiac death. We called on this experience, looking at the results we had found from our own studies and comparing them to studies that have been done in other groups of athletes in different parts of the world. We tried to identify any differences between what we’ve found and what other studies have found.
From drawing on our own experience we were able to provide valuable and practical insight in how to deal with diagnostic dilemmas faced when evaluating athletes for conditions capable of causing sudden death.
- Did anything interesting arise as a result of this ‘literature search’?
The thing I found most interesting from the literature search was how the data already out there on athletes are limited, particularly in Europe. What I mean by this is that studies from Europe are predominantly on white athletes and they only have a very small number of black athletes or athletes of different ethnicity. In the UK, similar to the US, we have a greater spread of ethnicities amongst the elite athlete population and I think it is very important to know about and recognise any differences between these ethnic groups. Our group has written quite a few papers in the past which have looked at large numbers of athletes of black ethnicity, so our own experience is quite broad from that regard.
- What conclusions can be drawn from the paper?
In both Europe and the US there is a consensus opinion that we should be screening athletes for conditions capable of causing sudden cardiac death. What this paper shows is that, if you are screening athletes, it may not always be as straightforward as the guidelines might suggest. Our own experience shows the kind of challenges that you might face – particularly in terms of differences between athletes and the overlaps between cardiomyopathy and physiological adaptation to exercise.
- What are the implications of this research in a wider context?
We wanted to highlight that actually, yes, there are guidelines which are very applicable but there are a good number of people who fall outside of that and therefore this paper provides information on what you do when you’re faced with these kinds of individuals – what other tests can you use; how you might interpret results which initially seem abnormal but in the context of, for example, a black athlete are actually normal for that individual but would be ‘abnormal’ if it was somebody else.
In practical terms, when you are screening big numbers there are lots of other factors to take into account other than just screening athletes per se. Ethnicity, sporting discipline and size of the individual must also be taken into account – things that may affect ECG and Echo changes. This paper highlights the need to be prepared that it may open up more grey areas or difficulties which may require further research to find out where the issues and differences are so you can make a decision one way or another.
If you’re a cardiologist, you obviously have an idea of the different types of investigations used for those individuals who are in a grey area between their pathology and physiology. So what the paper really adds is it tells you what your options are and what tests to do, which should help you get to the most definitive diagnosis.
If you’re a sports medic or a GP, you will still need to refer that patient into a local cardiology service in the first instance, but it gives you a broad overview of what your patient might have to expect – what investigations they are likely to go through – so you can warn them in advance of the types of things that would need to be done. You could also prepare and warn your athletes about what impact that might have on training regimes and other things like that as well.
- Does this now mean there is less need for specialism?
When it comes to evaluating athletes you may have to make a decision on whether you think somebody should or shouldn’t be allowed to continue participating in sport because you’re worried they might have a problem predisposing them to sudden cardiac death. So I do think this needs to be done by a specialist in the field.
You need to have people that have experience of evaluating athletes and are familiar with looking at their ECGs and Echo findings. You also need doctors who have experience of managing patients, who aren’t athletes, who actually have cardiomyopathy or ion channel problems of their heart and even experience of evaluating people that may have been affected by sudden death in their families.
- Is there more work to be done in this area?
Through our review we found areas where there is lots of research, but there’s also certain areas where there isn’t much research at all. For example, the whole area of something called early repolarisation changes found on the ECG needs to be looked at in more detail as we don’t necessarily know the implications of this – certainly over a long-term follow-up period.
Another important area is testing the right ventricle of the heart. Almost all studies in the past have focussed on the left ventricle, the left side of the heart, which is the meatier, thicker part of the heart. The only research that has been done on the right side has been on a very small number of athletes in their 30’s and 40’s and usually on endurance athletes. We’re also looking at how the right side of the heart is affected in conditions such as ARVC and how to differentiate that from normal changes you get with regular exercise on the right side of the heart.
Those two areas in particular do need more research and those are things that people in our own group are doing, as well trying to find out more about what’s ‘normal’ and what’s ‘abnormal’ and how to differentiate the two.
