Sudden cardiac death in athletes and preparticipation screening: what to know

Short answer

Sudden cardiac death in athletes is rare; but it is very important, because some of it can be prevented — or a life saved — through screening, early diagnosis, and effective on-field response. In young athletes the leading causes are inherited/structural heart diseases: hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy (formerly called dysplasia; in Europe, especially in Italian data, one of the most frequently demonstrated causes in young athletes; in US series, hypertrophic cardiomyopathy is foremost), congenital coronary vessel anomalies, and inherited rhythm diseases. Over the age of 35, coronary (vascular blockage) disease comes to the fore. The critical fact: most of these people are asymptomatic before the event.

For this reason two things are vital: (1) recognizing the warning signs — especially fainting/lightheadedness with exertion, chest pain, palpitations, and a family history of early/sudden death; none of these should be considered "ordinary." (2) Having an accessible defibrillator (AED) and a rehearsed emergency action plan on every pitch — because the first minutes determine survival.

Causes and epidemiology

Young athletes (≤35 years): Sudden cardiac death is rare and more common in men. The leading causes are hypertrophic cardiomyopathy (thickening of the heart muscle), arrhythmogenic right ventricular cardiomyopathy (formerly "dysplasia"; an inherited disease in which the right ventricular muscle is replaced by fatty-fibrous tissue, causing exercise-triggered rhythm disturbances; prominent especially in Italian screening data — current guidelines use the term "cardiomyopathy" instead of "dysplasia"), congenital coronary artery anomalies, and inherited rhythm (channelopathy) diseases (such as long QT, Brugada). Also among the causes are myocarditis (inflammation of the heart muscle), rhythm arrest triggered by a sudden blow to the chest (commotio cordis), and aortic diseases. An important caveat: in contemporary series, in a portion of cases no explainable structural cause is found at autopsy despite detailed examination; that is, the etiology distribution varies with the population and the examination method.
Master/older athletes (>35 years): The leading cause is coronary artery disease (arterial hardening/blockage); despite high physical fitness, silent plaques can pose a risk during intense exertion.
Most events occur during or immediately after exercise, and most people are previously asymptomatic.

Warning signs (must be evaluated)

The following are "alarm symptoms" and require cardiological evaluation before sport:

Fainting or lightheadedness with exertion (during exercise) — the most important warning sign; never to be considered ordinary fainting.
Chest pain/pressure with exertion.
Palpitations / a sensation of irregular heartbeats.
Shortness of breath disproportionate to light exertion, or unexplained excessive fatigue.
Unexplained or sudden death under age 50 in the family, or a history of known inherited heart disease.

Preparticipation screening: history, examination, and the ECG debate

The basis is common everywhere: a detailed personal and family history + physical examination.
Adding the ECG is debated: in the Italian model, in the region where mandatory ECG screening was applied, sudden death in young athletes was reported to fall markedly; by contrast, US guidelines were long cautious about mass mandatory ECG (cost, false-positive burden, the need for expert interpretation). The current approach is that in settings with appropriate resources and expert evaluation, the ECG can be added to history and examination — but it has not been made a universal requirement.
In Turkey, the ECG is a standard part of athlete evaluation: the Turkish Society of Sports Medicine's "Guide to Preparing a Sports Participation Certificate in Primary Care" for family physicians covers the ECG alongside history and examination in preparticipation evaluation; the guide includes normal and abnormal ECG findings in athletes and the roadmap to follow when these findings are seen (consistent with the European/ESC model). This guide was prepared especially for family physicians; because our own research showed that when a sports participation certificate is issued in primary care, the evaluation practice is not sufficiently known and is inconsistent between institutions. That is, the intended standard is clear (history + examination + ECG); the aim of the guide is to spread this practice in primary care.
The value of the ECG depends on experienced physicians who can distinguish the normal changes of the athlete's heart from disease (modern interpretation criteria reduce false positives).

Pitch-side AED and emergency action plan

In sudden cardiac arrest, survival is extremely dependent on time: each passing minute markedly reduces survival. Therefore:

Sports fields should have an accessible AED (automated external defibrillator); the target is for the interval between arrest and the first shock to be less than a few minutes.
Every club/school/event should have a written and rehearsed emergency action plan; field staff and coaches should know basic life support (chest compressions) and AED use.
The chain of survival: rapid recognition → early chest compressions → early AED → 112.

For clinicians

Incidence and etiology distribution vary with method/population (the share of HCM differs by series). The sensitivity of history+examination (including the 14-element tool) is low and false positives are high; Italy's ECG data are strong but single-region/observational and causality is debated — "the Italy experience is promising, the debate continues" is a more accurate framing than "ECG saves lives." Exertional syncope is a red flag. The most evidence-based population-level measure is widespread AED access and rehearsed emergency action plans.

Frequently asked questions

Why does a healthy athlete die suddenly of cardiac arrest?

Because there is often an underlying inherited/structural heart problem that gave no prior warning (for example thickening of the heart muscle or a rhythm disease). High performance can mask this problem; the event usually appears during intense exertion. For this reason warning signs and field preparedness matter.

My child/athlete fainted once with exertion; is it important?

Fainting or lightheadedness during exercise is a warning sign that must be taken seriously and should not be confused with ordinary fainting. A cardiological evaluation must be done before continuing sport.

Should every athlete have an ECG?

In Turkey, the ECG is a standard part of the athlete's health evaluation. The Turkish Society of Sports Medicine's preparticipation evaluation guide for family physicians covers the ECG in addition to history and examination (consistent with the European/ESC model). It is true that this is debated globally — some countries (e.g. the US) have been cautious about mass mandatory ECG because of cost and false positives — but the practice in our country is to include the ECG in screening. Correct interpretation of the ECG requires an experienced physician who can distinguish the normal changes of the athlete's heart from disease.

Does screening completely prevent sudden deaths?

No — no screening can prevent all sudden deaths, and the detection rate of history-examination is limited. For this reason screening alone is not enough; an accessible AED on the field and a rehearsed emergency action plan are at least as important as screening.

Why is the AED (defibrillator) so important?

Because in sudden cardiac arrest every minute markedly lowers the chance of survival. A ready AED at the pitch-side and people who know how to use it save lives in the critical minutes before the ambulance arrives.

Scientific references

Author's own works:
Kırık AB, Yüksel O, Dursun H ve ark. Visual or computer-based measurements: which is important for the interpretation of an athlete's electrocardiography? Rev Assoc Med Bras 2023;69(11).
Topçugil AB, Yüksel O, Kocahan T ve ark. Preparticipation screening practices in different health institutions. Spor Hekimliği Dergisi 2020;55(1):46-51.
Dursun H, Yüksel O. Increased risk of atrial fibrillation in athletes: a review. Turkish Journal of Sports Medicine 2014;49(4):139-46.
Specialty theses supervised by the author:
Topcugil Kırık AB. Evaluation of ECG findings in athletes according to the Seattle criteria and the 2017 international criteria. Medical Specialty Thesis, Dokuz Eylül University Sports Medicine, 2018 (Supervisor: Assoc. Prof. Oğuz Yüksel).
Gökçay O. Investigation of the frequency of sudden cardiac arrest cases in sports facilities in İzmir province, survival rates, and the use of automated external defibrillators. Medical Specialty Thesis, Dokuz Eylül University Sports Medicine, 2022 (Co-supervisors: Assoc. Prof. Oğuz Yüksel, Prof. Dilek Kaya).
Other references:
Maron BJ ve ark. AHA/ACC preparticipation cardiovascular screening of competitive athletes (14-element evaluation). Circulation 2014.
Corrado D ve ark. Trends in sudden cardiovascular death in young competitive athletes after implementation of a preparticipation screening program (Italy/Veneto). JAMA 2006;296:1593-601.
Sharma S ve ark. International recommendations for electrocardiographic interpretation in athletes. Eur Heart J 2018;39:1466-80.
Drezner JA ve ark. Sudden cardiac arrest / emergency action planning in sport (reviews). Br J Sports Med 2013 and related.
Turkish Society of Sports Medicine. Guide to Preparing a Sports Participation Certificate in Primary Care (for family physicians; including normal and abnormal ECG findings in athletes and the roadmap). sporhekimleridernegi.org

This information is for general guidance only; it does not replace an examination, a diagnosis, or your physician's individual advice. Please consult a physician for your symptoms. About the author: Doç. Dr. Oğuz Yüksel — Academic Profile.