Syncope toolkit

Syncope in athletes

The European Heart Rhythm Association (EHRA) estimates that one to two per 100,00 athletes under 35 years old die suddenly each year, with higher rates in males and Afro-Caribbean people.

In this section:

Syncope and sudden cardiac death (SCD) in athletes

Key facts:

A retrospective study found that 29% of athletes who died suddenly during competition had previously had symptoms suggesting cardiac disease
Most individuals that suffer SCD are asymptomatic, but syncope has been reported as the most common symptom before SCD
Pre-syncope carries the same prognostic implications as syncope
Syncope may be the presenting symptom of several conditions (hypertrophic cardiomyopathy, ARVC, anomalous coronary artery origin, myocarditis and long QT syndrome) that could cause sudden death in young athletes
One survey of young athletes revealed that 6.2% reported a previous syncopal episode. Syncope was unrelated to exercise in most cases (86.7%), was post-exertional in 12% and was exertional in 1.3%
Tilt table testing to evaluate syncope and presyncope in young athletes is to be undertaken with caution concerning interpretation as they may have an increased susceptibility to greater vagal tone leading to an increase in false-positive findings and inappropriate reassurance. If a fainting athlete experiences syncope during a tilt table test, this may not be the cause of the presenting syncope. The patient should be asked if the tilt table test produced symptoms similar to the presenting syncope. Cardiac causes may still need to be considered.

Exercise-related syncope

History remains key in evaluating exercise-related syncope and key questions include enquiring about previous syncope, palpitations and presyncope related to exercise, and family history of cardiac disease or sudden cardiac death in a young person (under 40 years). Points to consider:

It is important to distinguish between syncope occurring during exercise and syncope occurring after exercise
Syncope which occurs during exercise could suggest underlying structural heart disease and may be the only symptom preceding sudden cardiac death
Syncope occurring after exercise is more likely to be a vasovagal episode due to lack of venous return to the heart, dependent venous pooling and impairment of cardiac baroreceptors
On occasion syncope after exercise can be due to a cardiac cause
Guidelines suggest obtaining an ECG in all patients with exercise-related syncope.

Screening

Key points about athlete screening:

An Italian national screening programme in young athletes consisting of initial history examination and ECG has reported a 90% reduction in SCD
Screening programmes using combinations of questionnaire, physical examination, ECG and ECHO have been shown to reveal a 2-4% rate of abnormalities requiring further testing, with a rate of clinically significant abnormalities in about 0.3% of athletes
The American Heart Association Council on Nutrition, Physical Activity and Metabolism proposed a 12 step screening process aimed at preventing SCD in athletes

Medical history

Chest pain/discomfort on exertion

Sudden fainting/presyncope (judged not to be vasovagal, of particular concern when related to exertion)

Vertigo /dizziness on exertion

Heart murmurs

High blood pressure (> 140/90 or more on the first measurement)

Family history

Sudden death of the first-degree relatives aged under 50 years (parents, brothers, sisters, and grandparents)

Cardiovascular disease in close relatives under 50 years

Cardiomyopathy, LQTS, Marfan’s syndrome, ARVC, or other conditions with a risk of life-threatening arrhythmias or coronary artery disease in relatives

Physical examination

Heart murmur

Femoral pulse

Marfan’s syndrome manifestations

Sitting BP measurements

The value of the ECG in screening is uncertain as many disorders that can cause sudden cardiac arrest in athletes will not be detected on a standard ECG, and the variability of ECG interpretation is high
One study found that six out of eight sudden cardiac deaths had normal screening investigations including history, examination, ECG and echocardiography.

The role of the GP in preventing sudden cardiac death in athletes

'Increasing awareness about sudden cardiac death in athletes among general practitioners and primary care providers is an important step in helping to prevent events. Recognition of clinical features and symptoms that may indicate the presence of an underlying cardiac condition and the need for early referral to a cardiologist are essential for early diagnosis and initiating appropriate action'. (BMJ, 2015)