SINGAPORE - Even people who exercise regularly run the risk of dying of heart failure during a marathon if they have a pre-existing heart condition that has not been detected.
Such conditions often manifest only when extra strain is put on the heart.
Dr Reginald Liew, consultant cardiologist at Gleneagles Hospital, said: "During the marathon, they push themselves even harder, and the adrenaline rush makes everything more intense."
Even proper training may not be able to prevent a sudden cardiac death. The causes of such death among those aged below 35 fall into two categories, said Associate Professor Tan Huay Cheem, director and senior consultant at the National University Heart Centre. These are structural and non-structural heart disease.
Structural heart disease refers to problems with the physical structure of the heart, while non-structural refers to electrical abnormalities, such as an irregular heart rhythm.
Pre-existing heart conditions that go undetected may not have any symptoms, said Dr Kenneth Ng, consultant cardiologist at Novena Heart Centre.
People who have fainting spells when they exercise, develop excessive breathlessness or have a family history of sudden death should seek a doctor's advice before running a marathon, said Prof Tan.
Doctors interviewed advised those who plan to compete in endurance sports to go for a full medical assessment.
Dr Ng said: "The doctor will be able to advise on the amount of exertion the patient can undergo."
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