Ute Wilbert-Lampen et al. Cardiovascular Events during World Cup Soccer, The New England Journal of Medicine, Volume 358(5): 475-483, Jan 31, 2008.
Viewing a stressful soccer match more than doubles the risk of an acute cardiovascular event. In view of this excess risk, particularly in men with known coronary heart disease, preventive measures are urgently needed.and BBC report.
Interesting to see that immune system cell functioning is suggested as a possible mechanism. From our research, this struck us as highly relevant in many cases of chronic heart disease.
It's also worth thinking about why people get so emotionally involved in football matches. Perhaps Nick Hornby's Fever Pitch offers the best insight from fiction.