Debunking cardiovascular myths

PHOTO: Debunking cardiovascular myths

Do you know that one in three deaths in Singapore is due to heart disease or stroke, and that they accounted for 30 per cent of all deaths last year?

However despite heart disease being one of the top causes of death among Singaporeans there are still a number of myths surrounding it.

There are many different forms of heart disease, with the most common being Coronary Artery Disease (CAD), that due to the narrowing or blockage of the arteries that supply blood to the heart itself.

When a blockage occurs, there is insufficient blood supply to heart muscles, especially when demand for oxygen increases (e.g. on walking up a slope or on brisk walking), resulting in chest discomfort or tightness.

Typically, the symptom is relieved with the person stops exerting and rests.

This is known as angina, which is the cardinal symptom of stable CAD.

Acute coronary syndromes (ACS), which are unstable forms of CAD, occur when cholesterol plaques on the narrowed regions on heart artery rupture (or develop sudden spontaneous tear).

This results in formation of blood clots which either totally blocking the remaining lumen of the narrowed heart artery, or leaving very little room for blood to flow through.

The person would that develop a heart attack (ST-Elevation Myocardial Infarction, STEMI), or severe / prolonged / rest angina (unstable angina or Non-ST Elevation Myocardial Infarction, NSTEMI). All patients with ACS require urgent medical attention and treatment.

Awareness about heart health is the best prevention. Here to help you on the right track are some of the common myths around heart disease:

1. Cardiovascular disease only affects the elderly

While the risks do increase with age, the way you live your life now affects your risk for cardiovascular diseases later in life.

The foundations of heart disease can be planted as early as childhood, particularly if you obese, have a diet that consists of fried and fast food, allowing plaque to start accumulating in the arteries faster, which can later lead to clogged arteries.

A heart-healthy lifestyle needs to begin in childhood so that kids do not develop bad habits that stay with them in adulthood.

Parents should encourage their children to exercise at least 30 minutes every day, limit time spent in front of the television or computer screen, and have healthy, well-balanced meals.

This includes limiting the consumption of junk food and foods with high levels of saturated fat.

Stress can also be a factor in heart disease so it is important for working professionals to keep a work life balance and also go for regular health screening checks for blood pressure and cholesterol, for example.

2. If I am slim or exercise and maintain a healthy lifestyle, I will not get heart disease

Those who are thin, do regular exercise and eat properly are not completely immune from developing heart disease.

This is because cholesterol depositions, which are the most common cause of clogged arteries, can happen in thin people too.

So, don't be fooled by physical appearance.

Additionally, heart problems and heart attacks can also be brought about by genetic factors.

If there is a history of premature CAD in your family, i.e., male victims of less than 55 years of age and/or female victims of less than 65 years when they are stuck with the disease, you could be at risk too.

So in spite of how healthy you look or feel, get regular heart health checkup.

3. If my resting ECG is normal, I can assume I am safe from heart disease

It is not infrequent that a patient with CAD did not have warning signs until he/she suddenly experiences the symptoms of a heart attack.

Similarly, in patients with narrowing of heart arteries, it is not uncommon too that the resting ECG is normal, until he/she becomes unstable or having a heart attack.

This is because electrical changes on ECG depend on the balance between oxygen supply to, and demand of it by heart muscles.

Even when heart arteries have significant narrowing (thus, blood supply is reduced), our heart rate is not fast at rest.

Hence, the low myocardial oxygen demand is met by the even reduced blood supply, and resting ECG remains normal in appearance.

As such, it is important to know that a normal resting ECG does not exclude significant CAD.

Further and more accurate tests, e.g. treadmill exercise test or myocardial perfusion study may be required.

Therefore, if you are male, age 40 years or older, or female age 50 years or older, especially if you have CAD risk factors which include high blood pressure, high cholesterol, diabetes, being overweight, smoking or family history of premature CAD, you should go for further tests even if your resting ECG is normal.

4. I'd feel unwell if I had high blood pressure

Hypertension can lead to heart attack, stroke, renal or congestive heart failure.

Unfortunately, there are no early warning symptoms or signs in early stages (hence, hypertension is often called the "silent killer").

Hypertension can be difficult to detect without appropriate measurement of blood pressure.

The only reliable way to determine if one has hypertension is to monitor your blood pressure regularly.

The Singapore Ministry Of Health Clinical Practice Guidelines 1/2011 on "Screening for Cardiovascular Disease" recommends "periodic screening for hypertension for all adults aged 18 years or older".

I recommend home blood pressure monitoring using an electronic blood pressure set.

A word of caution - one has to pay attention to technical details of blood pressure taking to ensure that readings obtained are accurate.

5. I only need to start worrying about my cholesterol levels when I'm middle-aged

High cholesterol levels, like hypertension, can remain asymptomatic for decades.

While there might be physical signs suggesting its presence, the only reliable way to detect it is to obtain a blood test after 10 to 12 hours of fasting.

The Singapore Ministry Of Health Clinical Practice Guidelines 1/2011 on "Screening for Cardiovascular Disease" states that "It is strongly recommended that clinicians routinely screen men and women aged 40 years and older for lipid disorders" - even if they are asymptomatic.

The same guideline also recommends that "clinicians should routinely screen younger adults (men and women age 18 and older) for lipid disorders if they have other risk factors for CAD".

6. I'll know when I'm having a heart attack.

Although it is common to have severe chest pain, and other symptoms of heart attack which includes shortness of breath, cold sweat, nausea / vomiting, feeling lightheaded, and pain or discomfort in inner aspect of left arm (at times right), the jaw, neck or in between the two shoulder blades.

However, in some (especially older and patients with diabetes mellitus), symptoms may be absent or atypical.

The latter includes gastric discomfort or "heart burn" sensation, feeling generally unwell, shortness of breath only among others. It is important to learn that the longer the delay before the onset and treatment of a heart attack, the greater the amount of heart damage ("Time is heart muscle"!).

Hence, if you are experiencing any of the symptoms that suggest a heart attack, or if you are unsure if what you are experiencing could be a heart rate, it is better to call an ambulance earlier and err on safe side.

On other hand, if the symptoms proved to be a false alarm, one should learn to recognise and learn from it.

7. Heart disease mainly affects men

Many women think that heart disease is mainly a male disease.

In actual fact, heart disease and stroke combined is the leading cause of death among women in Singapore.

In the Singapore Heart Foundation's Go Red For Women Heart Health Awareness Survey in 2006 and 2009, less than 10 per cent of the respondents (8 per cent in 2006 and 9 per cent in 2009) were aware that heart disease and stroke is the No. 1 killer of women.

8. There is nothing I can do to prevent getting heart disease

There is plenty that can be done to reduce one's risk of heart disease.

All it takes is making simple lifestyle changes such as adjusting your diet, quitting smoking and exercising consistently.

However, it is also not enough to just know about what needs to be done, but actually doing them, and doing them correctly.

If you are afflicted by any one of the modifiable cardiovascular risk factors, you need to control it well.

If you are afflicted with more than one risk factor, you need to be more aggressive in managing all of them to treatment goals as combinations of risk factors multiply, rather than merely add, their individual effects on your likelihood of developing heart disease.

9. Diabetes mellitus is just another risk factor for CAD, just like hypertension or smoking.

Both the prevalence and incidence of diabetes are increasing worldwide, in conjunction with increased obesity rates and Westernisation of lifestyle and Singapore is no exception.

However, the disease often has a strong familial and genetic predisposition too.

Most adult onset diabetes is Non-Insulin Dependent Diabetes Mellitus (NIDDM or type 2 diabetes).

The risk of developing type 2 diabetes is associated with increasing age, obesity and lack of physical activity.

Diabetes is associated with a 3-fold increase in morality, mainly due to cardiovascular disease in Singapore.

There are studies to show that Diabetes Mellitus is "Coronary Heart Disease Equivalent" rather than a mere CAD risk factor - i.e., coronary heart disease (CHD) mortality in diabetic subjects without prior evidence of CHD is equal to that in non-diabetic subjects who already developed myocardial infarction, or any prior evidence of CHD.

10. I feel completely fine now that I've recovered from my heart attack, so I no longer need to take any medication

Many people who have survived a heart attack recover well and are able to lead normal lives. However, those who have had a heart attack are also at increased risk of having a second heart attack.

Therefore, it is crucial to undertake secondary prevention measures such as continued medication to reduce that risk.

Many patients think that they can stop the medication regimen (which generally includes an aspirin, a beta blocker, an ACE-Inhibitor, and a statin) prescribed by their doctor.

This is as they feel well but what they do not know is that this actually increases their risk of a subsequent heart attack and could even result in death.

As such, it is important to discuss your condition with your doctor, and adhere to his/her advice even if you feel fine.

There are also newer reversible oral antiplatelet medicines now available that may make it easier for your doctor to better manage your condition.

This article was contributed by Associate Professor Lim Yeah Teng, Senior Consultant Cardiologist of Cardiology Associates, Mount Elizabeth Medical Centre, and Adjunct Associate Professor of the Department of Medicine at Yong Loo Lin School of Medicine, National University of Singapore

For more information on heart disease, you can visit the Singapore Heart Foundation's website at