Hi all,
I think we need to look at things in perspective, and as always in medicine, keep an open mind when considering the differential diagnosis, in fact of any clinical symptomatology, in this case sadly, in SCD (Sudden Cardiac Death), retrospectively.
Although Luke Roughton's and Nerry's ideas of HOCM and "drugs", respectively, are possibilities, that is EXACTLY what they are: one of several possible explanations, which might be the actual causes in one or two instances.
THE MOST IMPORTANT point to take into account is that these reports, when publicized in the media, are not only aimed at laymen, but almost exclusively, created by laymen (sorry to say, but even the likes of Fergus Walsh are simply orators, not medics); the point I am heading towards is that the term "heart attack" is a very unprofessional and imprecise label, which refers to MI (myocardial infarction - "death" of cardiac muscle due to ischaemia [lack of blood supply] and hence of oxygen [anoxia]), AND CHANCES ARE THE MAJORITY OF THESE SCDs ARE NOT DUE TO MI (in line with the thoughts of Diamond Sky above, which suggests the opposite!)
The most likely causes of SCD include prolonged QT syndrome (as in Brugada disease - yes rare, but as we said there are hundreds of thousands of footballers), which can be caused by certain commonly used "drugs" (and I AM REFERRING TO LEGAL ONES this time!) e.g.older antihistamines, certain antibiotics [e.g. erythromycin], and last but not least, the antipsychotics (including, notably, the more recently introduced "atypical neuroleptics"). The classical sudden upturned head followed by collapse in torsades de pointes (multifocal ventricular tachycardia) is extremely unlikely to be noticed by anyone when the victim is playing a fast, action-packed sport. (the QT interval [corrected] is usually greater than 500ms in such situations).
Finally, I would say the best (and perhaps only) person who can answer this Q with any degree of expertise (AND WIKIPEDIA is a pretty poor website to consult for detailed authoritative information) is Dr Sanjay Sharma, Consultant Cardiologist, Guys and Kings College Hospitals group, who is THE world authority on SCD and inherited cardiac disease - but, of course, he would not have a split-second to even register on TSR! BTW, he was summoned to Spain few years ago when a Spanish football player collapsed and died there.
I hope my modest knowledge of cardiology adds some flavour to this discussion.
M (former medical student)