​Pre-participation cardiac screening helps identify underlying cardiac conditions or cardiovascular diseases that may be aggravated by exercise, or predispose a person to injury or sudden cardiac death¹.

By Dr Koh Choong Hou, Consultant, Department of Cardiology

The COVID-19 pandemic has upended lives and social norms across the globe, bringing about devastating impact on the economy and population health. 

In spite of this, a silver lining has emerged from the imposed lockdowns and safe distancing measures – the rise of outdoor exercises. Now, outdoor exercises to the general public are not only means of getting out of their homes, but also ways to keep themselves physically active and healthy. With this rising prevalence in sports participation, there is also an increasing interest in cardiovascular safety during exercise, especially with the sporadic reports of sudden death in young individuals who appeared to be in seemingly good health.

Why the need for pre-participation cardiac screening? 

When news reports on sudden deaths of healthy and young individuals during sports are commonly in the spotlight and of public interest when they occur, such events are exceedingly rare amongst the multitudes that regularly exercise daily. Events like these should not deter the general population from engaging in appropriate levels of physical activities, as it is a well-known fact that physical exercise improves overall well-being and prolongs healthy years. That being said, individuals with undetected or silent cardiovascular conditions may be at risk when engaging in heavy physical activities, and adequate precautions should be taken prior to their commencement of intense sports.

Sudden cardiac death or collapse during sports is consequent to an acute failure of the heart to maintain the circulatory system for blood flow to vital organs, and may be contributed by any one of the following mechanisms: electrical heart issues (unstable heart rhythms), structural heart issues (abnormal or weakened heart muscles), or inadequate blood supply to the heart muscles. If such conditions exist in an individual, intense physical activities may act as a trigger to cause any underlying heart conditions to unmask and suddenly deteriorate, leading to life threatening situations. The key to avoiding such devastating consequences is hence centred on the following principles – prevention, detection and intervention – succinctly summarised in the table above.

Who needs pre-participation cardiac screening?

Most individuals who are healthy, or with well-controlled chronic medical conditions such as hypertension, hypercholesterolemia, and diabetes, may proceed to take part in light to moderate intensity exercises without cardiac screening. However, if they have more complicated conditions, for example, prior heart attacks, previous stenting or bypass graft surgeries, weakened heart function, heart muscle disease, heart valve disease, and heart rhythm problems, it is best to consult their medical providers or cardiac specialists, before engaging in sports, especially those of moderate or high aerobic intensities. As a simple rule of thumb, high intensity aerobic activities usually result in heart rates exceeding 75% of the predicted maximum heart rate (maximum heart rate is estimated by deducting the age from 220), with the person not being able to speak even a few words during the activity; moderate intensity aerobic activities usually result in heart rates exceeding 65% of the predicted maximum heart rate, with the person generally still being able to speak in short phrases or sentences during the activity.

How is pre-participation cardiac screening performed? 

In general, most doctors are able to provide basic advice and screening via comprehensive history taking and physical examination. In addition, sports participants may also perform simple self-screening questionnaires available online (an example is the Physical Activity Readiness Questionnaire, or “PAR-Q”³), and seek further medical advice if there are abnormal responses to the questionnaires.

Broadly, the following groups of sports participants may require referrals to specialists (cardiologists or sports medicine practitioners) for further assessment:

1. Sedentary or high cardiovascular risk individuals planning to take part in high intensity sports or competitions
2. Individuals with known cardiovascular conditions (chronic heart failure, ischaemic heart disease, valvular heart disease, etc)
3. Individuals with abnormal clinical findings (such as an abnormal electrocardiogram) or ongoing symptoms (palpitations, chest pain, unusual breathlessness)

Depending on the clinical circumstances, your doctor or cardiologist may perform any of the following cardiac tests before further advice: 

1. Electrocardiogram (ECG). This records the electrical activity of the heart, including the heart rate and rhythm, as well as displays any potential underlying structural heart conditions.
2. Exercise Treadmill Test (ETT). This is essentially an ECG performed while undergoing a run on the treadmill machine, and allows the detection of any underlying heart conditions that can be unmasked with physical stress.
3. Echocardiogram. This is an ultrasound study of the heart and records live moving images at rest, and reflects any structural or functional abnormalities of the heart.
4. Advanced functional cardiac imaging. These are second line scans available only in the hospitals that combine stress testing together with an imaging modality (ultrasound / CT scan / MRI) to assess for potential ischaemic heart disease.
5. CT coronary angiogram. This is a non-invasive form of imaging using a CT scanner, assisted by an intravenous dye, to detect any blockages of the heart arteries.
6. Cardiopulmonary Exercise Test. This is similar to the ETT, but with added components to measure both heart and lung functions to comprehensively assess overall cardiopulmonary health and fitness.

The specialist may then recommend whether it is safe for you to proceed with sports participation, or if further clinical interventions are required, based on the findings of tests.

Conclusion

Exercise plays an important role in our overall well-being, but selected individuals who may have predisposing cardiac conditions may require further cardiovascular assessment before they undertake physical activities of moderate to high intensities, to prevent the risks of triggering any potential cardiac events during these activities. It is recommended to always seek medical advice when in doubt, before embarking on higher levels of exercise, especially if they experience disconcerting symptoms.

¹ Mont L, Pelliccia A, Sharma S, et al. Pre-participation cardiovascular evaluation for athletic participants to prevent sudden death: Position paper from the EHRA and the EACPR, branches of the ESC. Endorsed by APHRS, HRS, and SOLAECE. European Journal of Preventive Cardiology. 2016/11/04 2016;24(1):41-69. doi:10.1177/2047487316676042

² World Health Organization Fact Sheet: Physical Activity. https://www.who.int/news-room/factsheets/detail/physical-activity

³ Ministry of Health, Health Hub – Different Types of Physical Activities. https://www.healthhub.sg/live-healthy/387/TypesOfActivities 

⁴ www.sportsingapore.gov.sg/Sports-Education/Sports-Safety/Sports-Safe-U-Guide