How to prevent an exercise related sudden cardiac death?

Sudden cardiac arrest is one of the conditions, where the advancements in treatment modalities have not significantly reduced the mortality over years. There are multiple reasons for sudden cardiac arrest but the most common one is a sudden onset of irregular heartbeat. This leads to either a drop or block in the blood flowing out of the heart to the entire body.

Health and physical activities:

The health benefits of regular physical activity against heart attack and many other diseases is very well established.  There are a lot of scientific evidences to prove that people doing regular physical activity have 20-30% lesser risk of dying early. they also tend to benefit against diseases like diabetes, high BP, heart attacks, brain stroke, colorectal cancer, breast cancer and bone weakness. Regular physical activity will also help in reducing body weight.

Step by step, regular, moderate exercise reduces the risk of heart attacks. But strenuous physical activity might increase the risk of heart attack and sudden death due to various reasons.

 In persons lesser than 30 years of age the common reasons are:

1. Undetected congenital heart diseases since birth
2. Valve problems
3. Disease of heart muscle
4. Problems in the electrical system of the heart
5. Thinned out major blood vessels causing sudden rupture

In persons greater than 30-40 years of age the common reasons are:

1. Complete blockade of the blood vessels of the heart due to rupture of a pre-existing small block – This is the most common reason.
2. Clot formation in the blood vessels of the heart due to the abnormal increase in the heart rate and BP leading to stress on the heart.
3. Clot formation in the blood vessels of the lungs
4. Scar formation in the heart due to a past heart ischemia

What is vigorous or strenuous physical activity?

During this physical activity you will not be able to speak even few words without gasping for breath. Eg. Jumping rope, Running, Aerobic dancing, cycling at more than 10 miles per hour speed, Hiking uphill, walking with a backpack etc.

What happens during such vigorous activities?

Vigorous physical activity is the preceding event in more than 10% of the case of heart attacks.  Such activities cause a release of adrenaline and nor adrenaline in the body which will increase heart rate, BP and free fatty acids in the blood. Repeated vigorous activities in susceptible individuals with heart muscle disease can lead muscle ischemia that can lead to cell death and scar formation. A scarred tissue can be a trigger for electrical disturbances and sudden death.

What kind of precautions need to be taken while exercising?

1. Healthy adults should start only step by step exercise from light to moderate and then to vigorous type of exercises by a proper trainer.
2. Patients with known heart problems should always consult a cardiologist before starting a exercise programme and it has to be done in a very careful graded and supervised manner
3. Vigorous exercise in extreme cold and hot environment might increase the risk of heart attack and death. Better to be avoided.

What precautions can be taken at the training centres?

1. The trainer or the coach should be trained to provide basic life support.
2. The centre should have automated external defibrillator facility.
3. Transportation facility to the nearest hospital.

How much exercise is enough to protect the heart?

Guidelines are very clear. It is only 30 min of moderate physical activity or 15 min of vigorous physical activity at least 5 days per week is more than enough  to protect your heart from heart attack and most of other diseases. So strenuous exercise for longer periods are not recommended in any international l guidelines for and they have not shown to provide any additional benefits.

How to prevent an exercise related sudden cardiac death?

Even though we can’t completely prevent sudden cardiac deaths associated with exercises there are a few steps to minimise the risk. Most youngsters with sudden cardiac deaths have a pre-existing heart disease, that can be easily diagnosed by proper evaluation. So before getting into vigorous physical activities it is better to get a

1. Screening for any congenital heart defects (defects present from birth)
2. Screening for electrical disturbances in the heart by an ECG and a Holter monitor if required.

How frequently do you need to undergo cardiac evaluation?

American heart association recommends, a doctor consultation and evaluation once before participating in athletics and once in 2-4 years thereafter or as per the doctor’s advice.

In Italy for the past 40 years all sports persons should undergo a mandatory screening by a doctor and they found significant reduction in their death rate.

It is also recommended that diabetics and anyone above the age of 45 years who wants to do vigorous physical activity should also undergo cardiological evaluation before participating.

When to report to a cardiologist?

Inspite of precautions and evaluation, if a cardiac event is to happen, you need to know when to report to a doctor. Meet your cardiologist if there is

• Chest pain or discomfort or heaviness.
• Unusual fatigue and tiredness.
• Giddiness or episodes of loss of consciousness.
• Fast heartbeat (palpitations).
• Excessive breathing difficulty.
• Severe headache.

A doctor will be able to assess the risk profile based on pre-existing disease (as detected by clinical evaluation, ECG and ECHO) and family history and associated high-risk lifestyle behaviours like smoking etc. so it is very important to give a detailed and honest history to the doctor for complete risk assessment and proper advice. The above said assessment will help in risk reduction but there is no guarantee that a sudden cardiac event can be completely avoided.