Risk factors such as heart problems have to be present before sudden death occurs during endurance events
YOU’RE young, you’re healthy and suddenly you’re history. Recent reports about the rising number of people with sudden cardiac death (SCD) may have created the perception that strenuous exercise could be fatal for some– including the young.
But this is not true, says Dr Ching Chi Keong, a senior consultant with the Department of Cardiology and co-director of Electrophysiology and Pacing at National Heart Centre Singapore (NHCS). He was responding to queries from The New Paper following the sudden death of 55-year-old businessman Lee Khoon Bok. Mr Lee, who had a history of high blood pressure, suffered sudden cardiac arrest 300m from the finishing line of the 100Plus Passion Run on May 21. He had taken part in the 5km segment of the event. His death brought the attention back to SCD.
Dr Ching added that the incidence of SCD in Singapore went up from 26 per 100,000 population in 1998 to 34 per 100,000 in 2007. But this is due mainly to anageing population. Of the 1,538 cases of sudden cardiac deaths in 2007, 67 per cent involved those above 60 years of age. Fewer than 3 per cent of deaths hit those below 35. Dr Ching also cited a 2003 study of 229 sudden unexpected deaths in people aged 18-60.
The study, a collaboration between NHCS and the Health Sciences Authority, found that 81 per cent of all SCDs were caused by coronary artery disease, which makes the condition the most common cause of sudden death. Before dying suddenly, almost half of all patients had triple vessel disease, where all three of the blood vessels supplying the heart muscle had blocks. Agreeing, Dr David Foo, head and consultant of the cardiology department at Tan Tock Seng Hospital, said the overall incidence of SCD during exercise is estimatedto be “less than 1 per 10,000 per year”.
He said the most common causes of SCD in the younger age group are “congenital or hereditary abnormalities” in heart structure or major blood vessels, or heart rhythm disorders which increase the risk of death during exercise. Endurance events continue to be popular. Indeed every weekend in June, there will be at least two endurance events. The coming weekend will see the Singapore Pools Metta Charity Run. Theevent has both 5km and 10km segments. Two other endurance events – the NTU X-Physique and NUS Legs & Paddle 2011 – are also lined up for the weekend.
Dr Ching said that, for most people, there is no need for special screening tests before taking part in sports. The Singapore Sports Council’s Committee on Sports Safety recommends a simple self-administered questionnaire. The questionnaire, known as PAR-Q, which stands for Physical Activity Readiness Questionnaire, can be found on the Singapore Sports Council website.
Among the questions: Have you had chest pain in the past month when you were not doing physical activity, and do you lose your balance because of dizziness or do you ever lose consciousness?
Dr Foo advises those who wish to undertake any form of exercise to understand their bodies and limitations. They should be aware of the risk factors for coronary artery disease. This is especially so for the older age group. These risk factors include age (men above 45 years old,womenabove 55), family history of heart disease or sudden death, smoking, sedentary lifestyle, obesity, high blood pressure, high cholesterol levels and diabetes. Also, those who have cardiovascular symptoms such as chest pain, breathlessness or fainting spells, should have medical screening and clearance for vigorous exercises. They should seek advice from their doctors and get recommendations on the type of exercise suitable for them, said Dr Foo.
Certain groups of people should get tested, Dr Ching added. These include people with chest pain when they exert themselves or people who often black out or have a family history of sudden death. If a person collapses from SCD, the most effective way to try to revive him is to deliver an electrical shock to the heart using a defibrillator. The key to survival is early defibrillation. It has been found that each minute of delay before defibrillation reduces the chances of survival by about 10 per cent. Dr Ching said people with chest pain that typically lasts more than five minutes after exertion should seek medical help. This is particularly important if chest pain is accompanied by shortness of breath, jaw or shoulder ache andcold sweat.