What They Don’t Tell You About Cardiovascular Risk in Sports
When a young athlete experiences sudden cardiac arrest during training or competition, the reaction is usually immediate: surprise, disbelief, and many questions. After all, we are talking about someone active, well trained, and, in theory, healthy. How can the heart fail in this context?
Sudden cardiac arrest in athletes is rare, but its impact is far greater than its frequency, precisely because it affects young individuals, often without a previous diagnosis of cardiovascular disease. Understanding what lies behind these events is essential for those working in health, sports, and performance.
An important point from the outset is that, in most cases, sudden cardiac arrest in young athletes is not related to myocardial infarction. The most common mechanism is a severe ventricular arrhythmia, which causes the heart to stop pumping blood effectively, usually during or shortly after intense exercise, when the heart is under significant electrical and hemodynamic stress.
In practice, this typically occurs in hearts that already have an underlying condition, often silent. Among the most frequently associated causes are:
• hypertrophic cardiomyopathy
• arrhythmogenic cardiomyopathy
• congenital coronary artery anomalies
• myocarditis
• channelopathies, such as long QT syndrome and Brugada syndrome
One finding that stands out in more recent studies is that, in a relevant proportion of cases, autopsy reveals no evident structural abnormalities in the heart. In these scenarios, genetic testing, known as molecular autopsy, can identify variants associated with electrical disorders in about one quarter of athletes. In other words, the problem may lie in how the heart’s electrical signals are generated and conducted, rather than in the organ’s structure.
As age increases, the profile changes. From the age of 35 onward, the main cause of sudden cardiac arrest becomes atherosclerotic coronary artery disease, as seen in the general population. In these cases, exercise can act as a trigger for arrhythmic events in a heart with established disease.
This naturally leads to an important question: is prevention possible? In many cases, yes. A well conducted pre-participation cardiovascular evaluation remains one of the most important tools. When it includes a thorough medical history, assessment of family history, careful physical examination, and a 12-lead electrocardiogram, the likelihood of identifying conditions associated with sudden cardiac arrest increases significantly.
When interpreted by professionals trained in sports cardiology, the electrocardiogram can detect approximately two thirds of diseases associated with sudden cardiac death, with a low false-positive rate. Still, not all events are preventable. For this reason, emergency preparedness is just as critical as prevention.
Survival after sudden cardiac arrest depends primarily on the time to defibrillation. Sports environments with well defined emergency action plans, teams trained in cardiopulmonary resuscitation, and rapid access to automated external defibrillators have significantly changed the prognosis of these cases.
Another important point: surviving sudden cardiac arrest does not necessarily mean the end of sports participation. With accurate diagnosis, appropriate treatment, and specialized follow-up, many athletes are able to return to sport safely, through individualized and shared decision making.
In summary, sudden cardiac arrest in athletes is rare, but it requires continuous attention. The combination of adequate screening, well prepared environments, and sound clinical decision making has not only reduced mortality, but also helped preserve sports participation with greater safety.
