In this ‘Ask the Specialist’ Q&A forum, Assistant Professor Huang Zijuan, Consultant from the Department of Cardiology at the National Heart Centre Singapore (NHCS), a member of the SingHealth group, answers your questions about the symptoms, risk factors and screening for heart disease.

To submit your question, simply email it to marcom@healthxchange.com.sg

The forum is open from 1 Sep to 28 Sep 2023.

Please allow up to two weeks for your question to be answered. We reserve the right to choose which questions to answer and to close the forum early. 

Do bookmark this page and check back often as we will progressively add answered questions on this page. Only answered questions will be shown.

Want to know your risk of heart disease? Now you can find out!

Heart disease is a significant health concern, which causes one in three deaths in Singapore.

However, armed with knowledge, you can take proactive steps towards prevention and early detection for a better heart health.

Cardiovascular disease can present itself with warning signs that should not be ignored, with common symptoms including:

  • Chest pain, 

  • Shortness of breath and 

  • Fatigue 

Early detection is also important in the management of heart disease. Various screening methods are available to assess an individual's risk profile and current heart health.

Don't miss this chance to ask our cardiologist, Asst Prof Huang Zijuan, more about the symptoms, risk factors and screening for cardiovascular diseases, to protect you and your loved ones!

Plus, you can find out your risk for heart disease directly on your mobile phone.

Try the new Heart Disease Risk Calculator on Health Buddy - it's free!

Find out your risk of heart disease with the Heart Disease Risk Calculator from NHCS, available through the Health Buddy app. This user-friendly tool uses a combination of health metrics to estimate your risk of developing heart disease.

If you are already a Health Buddy app user, simply tap on "Heart Care" on the home screen. Next, tap on "Heart Disease Risk Calculator". Go on, give it a try now!

About Asst Prof Huang Zijuan

Asst Prof Huang Zijuan is a Consultant with the Department of Cardiology at the National Heart Centre Singapore (NHCS). Her clinical interest is in cardiac computed tomography, nuclear cardiac imaging, and cardiac rehabilitation and preventive cardiology.

Question and answers on heart disease risks

1. Question by Khin

Dear Doctor,

I had twice visited the A/E dept after a shortness of breath and a 20 sec faint with heavy cold sweating. After ct scan, x-ray, blood tests, ecg, tests followed by 2 specialist visits, I had been cleared with no adverse comments.

I had been given a 14 days trial of an electronic heart monitoring but no visible result found. Can you explain why and a possible reason behind it with what precautions that I shall be taking for the next time if any bad thing ever happens again?

Answer by Asst Prof Huang Zijuan

Dear Khin,

One possibility would be abnormal heart rhythm (where the heart beats too fast or too slow or is irregular). It could be that the abnormal rhythm did not happen to occur during the 14-day monitoring and hence the result was alright. If you experience palpitations again you could get someone to accompany you to the nearest GP clinic, which has electrocardiogram (ECG) capabilities, to get an assessment when the episode is ongoing. If feeling very unwell, please seek emergency medical attention - call 995 and for the ambulance to come to the emergency department.

There are also other rhythm monitoring devices on the market that some patients found useful, for example Apple and Samsung smart watches that can record a one lead ecg or the device called Alivecor.

2. Question by Wee Chuan

Hi Doctor,

I am a Chinese, male, 58. My blood pressure reading in the morning after I have brushed my teeth ranges from 118-127 / 72-80. At night, after my shower just before bedtime, my reading tends to range from 127-138 / 74-82.

In other words, the blood pressure monitor usually pronounces my morning reading as normal, and the night reading as high normal.

Is this something to be worried about? Does this mean I have hypertension?

Answer by Asst Prof Huang Zijuan

Dear Wee Chuan,

Your blood pressure is acceptable. Generally speaking for a otherwise healthy person, The desirable BP level is below 140/90 mmHg, however if you were able to reach even better levels at 120/80 mmHg or below with diet and appropriate types of exercise, it would lower cardiovascular disease risk even further.

You can try the heart risk calculator available in SingHealth Health Buddy app which myself and others from the SingHealth Health Buddy team helped to develop. This is based on a model calibrated using Singaporean data, and will calculate your risk of heart attack within the next ten years, after you enter your health info e.g. BP and cholesterol.  If result falls under the green range it would mean that you are at a good level of risk compared to your peers of the same age. If your risk is slightly higher, and the result appears in the orange or red range, the app will show ways to reduce those particular risk areas, such as resources on diet, exercise and medication for your condition.

Alternatively, you may find out more from the following articles:

3. Question by Lynn

Hi Dr,

I have suffered high LDL for many years. I stopped taking statins some years ago as it was giving me muscle aches. The polyclinic doctor did not disagree to my choice (to stop medication).

A recent lipid profile test revealed that my total cholesterol and triglycerides levels to remain high. The polyclinic doctor recommended resuming medication at a much lower dosage (alternative days, half a tablet) and I believe, a different class of statins.

Unfortunately, even at a lower dose, statins are giving me joint pain, muscle aches and headache. I feel weak (discomfort and unwell) and this affects my day-to-day activities such as work, studio fitness classes etc.

I do not usually take seafood or red meat. I am cutting down on fried foods. I am moderately active (despite my fatigue).

I’d like to find out more about the risks should I stop taking statins again. Thank you!

Answer by Asst Prof Huang Zijuan

Dear Lynn,

To find out your risk of a heart attack with your bad cholesterol remaining at your current levels, as well as how the risk would improve if you controlled your cholesterol, you may use the heart risk calculator in the Health Buddy app.

If the result falls under the green range, it would mean that you are at a good level of risk compared to your peers of the same age. If your risk is higher, appearing in the orange or red range, there would be resources for you on how to reduce the cholesterol through various methods.  Alternatively you can refer to these articles:

Exercise lowers cholesterol by up to 5%, diet lowers cholesterol by a bit more and medications lower bad cholesterol by more than 60% sometimes.

If medications are really needed, supposing you are a higher risk person, there are a couple of options and there may be some that do not cause you side effects.

4. Question by Siow Wah

Dear Prof Huang,

Chest pain is the most common symptom of heart attack. Could you share in greater detail which part of the chest is the heart attack occur most frequently and what is the best course of action to be taken by the patient or his family?

Thank you and warm regards.

Answer by Asst Prof Huang Zijuan

Dear Siow Wah,

Heart attack happens when a heart artery suddenly gets blocked. Chest discomfort is typically in the centre of the chest but can also be in other regions, ranging from the jaw to the upper abdominal area, and sometimes the back.

If you experience severe discomfort, seek immediate medical attention. Check out this video by NHCS to learn more: ‘Heart Attack: Myths, facts and how to reduce the risks’.

5. Question by Tan

Hello Doctor, 

I want to stop taking Cardigan 100mg as I have low haemoglobin, low RBC and Iron. Stool test was positive. I am looking at replacing Cardiprin with Nettokinase. Is this possible? Thanks.

Answer by Asst Prof Huang Zijuan

Dear Tan,

It appears that you may be referring to the medication Cardiprin? It depends on the reason you were started on Cardiprin. 

For example, if you had previous stroke or severe heart artery blockage before, then it would be advisable to continue a blood thinner for adequate reduction of risk for subsequent cardiovascular disease events. Hence, a supplement would not be adequate in that situation to reduce your risk as compared to a blood thinner. 

However, if you have high bleeding risk due to various reasons then your doctor will discuss with you and decide if it would be better for you to stop the blood thinner.

6. Question by Bernice

Dear Prof,

Should I be concerned if my treadmill results at Helios project indicated Sinus Bradycardia

Looking forward to hearing from you. Thank you in advance.

Answer by Asst Prof Huang Zijuan

Dear Bernice,

Not necessarily, as sinus bradycardia can sometimes be a normal state in well trained individuals who do regular exercise. It is best to consult a doctor with your results to see if there is really an issue.

7. Question by Abdul Riffin

Hi Dr,

I have just went through a bypass process 4 months ago at Heart Centre.

I would like to know if there are any foods which I need to avoid?

If yes, what are they? Thanks!

Answer by Asst Prof Huang Zijuan

Dear Abdul Riffin,

There are many foods to avoid, and also many that will be good for you to take. You may refer to these resources contributed by me, "Blog Article: Diet for Cardiovascular Disease Risk Reduction".

You may consider incorporating to some extent the Mediterranean diet. We are currently developing a new resource on this, stay tuned to our NHCS webpage on patient education resources!

8. Question by Jean

Dear Prof Huang,

My mother had ischemic stroke due to atrial fibrillation in August 2017 resulting in left immobility.

Since late last year, her ProBNP has been extremely high at 8000+ with her heart rates hovering 40+.

Lately she is having night sweats occasionally. She is also having oxygen desaturation since last Saturday and now on 1 litre of oxygen constantly.

May I know if the above symptoms are related to her heart issues? Thanks.

Answer by Asst Prof Huang Zijuan

Dear Jean,

It is possible that it may be due to her heart, though there are also other potential contributors if she has other medical issues, like kidney or lung issues. It is best to bring her to her primary doctor for a check as soon as possible. If in significant respiratory distress, it is strongly advisable to bring her straight to the nearest emergency medicine department.

9. Question by Chloe

Dear Prof Huang,

I am in my 40s this year, female, my height is 158cm and weight around 65kg.

I have asthma since young, hyperthyroidism detected last year and recently endometriosis so I am on carbimazole, visanne and inhalers once a day.

My mum had heart disease when she is 60+. Recently I had an episode of sudden heart palpitation which went up to 210, I can feel like my heart is pumping so fast which cause my chest to be tight and slight pain, which really frightened me. This happens when I’m just standing and doing nothing. So no anxiety or thing that gets me excited or overly tired, it lasted for around 43mins.

I have done ECG sometime in Apr or May and the result came out fine.

Should I be worrying about this incident cos it really scared me or what sort of test should I be going for? and if it happens again how should I save myself?

Really appreciate your advice and help.

Answer by Asst Prof Huang Zijuan

Dear Chloe,

The palpitations may be due to an abnormal heart rhythm. It is best to see a doctor and get a referral in to seek a specialist’s inputs, where further tests will be recommended after assessment. One more thing is to check that your thyroid condition is under good control as it can contribute to abnormal heart rhythms if thyroid hormone level is too high.

It is good to check for nearby clinics with ECG capabilities so that if the symptoms happen again, you can arrange for someone to accompany you to receive an ECG to detect what is happening. If you experience significant chest discomfort or breathlessness or dizziness with the palpitations, seek immediate medical attention - call an ambulance at 995 to the emergency department.

10. Question by Mei Chuen

Hi Dr, I have 2 questions:

a) How is heart failure diagnosed? Does having ischemic heart disease and low ejection fraction mean a patient has heart failure?

b) Can the CT calcium scoring test show the severity of blockages in the coronary arteries?

Thank you for your assistance.

Answer by Asst Prof Huang Zijuan

Dear Mei Chuan,

Heart failure is diagnosed from a combination of symptoms, signs and also tests like echocardiography. Having a low ejection fraction indicates the person has weak heart function, which is the underlying issue in heart failure.

CT (computed tomography) calcium scoring does not show the severity of blockages in the arteries. However, it can be used to estimate the risk of heart attack in combination with other clinical risk factors such as cholesterol and blood pressure levels.

11. Question by Lim KS

Dear Asst Prof Huang,

I have few questions concerning about vessel blockages which I hope it is related to the heart topic.

a) I am at my late 50’s, how can I know the condition of my blood vessel to prevent a stroke or heart attack?

b) I feel tired easily, does it mean that my blood flow is poor?

c) I am not a coffee or alcohol drinker and I started to have double heartbeat in my earlies 50’s. It happens a few times a year and lasted about 12 hours before the heart rate goes back to normal. During the double heartbeat, my blood pressure will drop to quite low in which I will feel restless and giddiness. What can be the possible cause and any precaution needed?

d) With regards to condition of blood vessels, is there an check-up programme available which is subsidised by MOH?

Thanks in advance for answering my questions.

Answer by Asst Prof Huang Zijuan

Dear Mr Lim,

a) While there are various investigations to find out the current state of your blood vessels, what is important is to reduce your risk of having a heart attack. The key to reduce the risk of heart attack in most cases is to control risk factors. Many of us, to some extent, could have deposits of cholesterol in our arteries, depending on how well we have controlled various risk factors in the past. Whether these deposits in the arteries will rupture and suddenly cause a heart attack would depend on several factors such as bad cholesterol levels, smoking status, sugar levels, type and amount of regular exercise done, diet, and etc.

If you are experiencing symptoms of concern such as a new decrease in exercise tolerance, chest discomfort (especially on exertion), you should seek medical attention so the appropriate investigation can be done to assess your condition. However, if you did not have symptoms of concern, and do not have adequate medical reason, it may not be necessary for you to go for certain tests. Certain scans may involve radiation exposure, or may involve risks of stroke, heart attack and abnormal rhythms when undertaking the test. Therefore, it would be best to focus on getting your risk factors controlled with advice from your doctor, which will be beneficial to your vessel health, and reducing risk of heart attack and stroke.

b) Tiredness does not necessarily mean your blood flow is poor. Being tired can be due to multiple factors, such as simply not having enough rest.

c) These sound like irregular heartbeats. It is best to seek immediate medical attention if you feel dizzy, breathlessness, chest discomfort or even faint during episodes of these palpitations. Certain irregular heart rhythms can pose a significant risk, and in severe cases, they have the potential to result in cardiac arrest, where the heart ceases to function.

d) To my best knowledge, there is currently no specific programme with subsidies for overall cost on testing for vessel blockages. If you are Singapore citizen or permanent resident, and are referred by approved Community Health Assist Scheme (CHAS) clinics or polyclinics, you will be eligible for subsidies for medical tests which are clinically indicated as subsidised services.

You can schedule a consultation with a primary care physician to discuss your concerns. Following the consultation, the doctor can decide whether to recommend relevant tests or make a referral if necessary.

12. Question by How Sheng

Hi Dr,

I have been doing Calcium Score test a few times on average once every 3 or 4 years.  It's been zero. 

I am told that Calcium score detects only hard blockage and not soft plague build up.  So should I do CT scan for soft plague blockage? Does it replace the Calcium score or should I do both? Thanks.

Answer by Asst Prof Huang Zijuan

Dear How Sheng,

I would assume that you are doing regular calcium score test to either mitigate or manage the risk of heart attack.

If so, I would like to share that what reduces the risk of heart attack is actually the control of risk factors. Like many us, it is possible that we have accumulated cholesterol deposits in our arteries to varying degrees, depending on how effectively we have managed different risk factors in the past.

Whether these deposits in the arteries will rupture and suddenly cause a heart attack would depend on several factors such as bad cholesterol levels, smoking status, sugar levels, type and amount of regular exercise done, diet, and etc.

If you do not have any symptoms, it will be more meaningful to start managing your risk factors by addressing these issues instead of doing a CT coronary angiogram. However, if you do already have symptoms of concern, like new decrease in exercise tolerance, chest discomfort (especially on exertion), you should seek medical attention so the appropriate investigations can be done to assess your condition.

If you did not have symptoms of concern, certain tests can be inappropriate, such as CT coronary angiogram which involves contrast administration and radiation exposure. CT calcium score has lower radiation than CT coronary angiogram and hence can be used even in individuals without symptoms. However, if you did not have adequate reason to proceed for such tests, it would be best to instead focus on getting your risk factors controlled with proper advice from your doctor, which will be more beneficial for vessel health.

13. Question by Soon Heng

Hi Dr,

I am always low on HDL since young. Was told by doctor that the way to increase it is to exercise. I have always been an exercise fanatic, running marathons and now at 73 years old, doing brisk walk for 10 to 12 km daily, yet my HDL remains low.

Understand that this has to be higher to reduce my lipid ratio which is an indicator of heart attack.

My Question: Other than exercise, what other means can I increase my HDL? What kind of food can help? Thank you for your advice.

Answer by Asst Prof Huang Zijuan

Dear Soon Heng,

Focusing on increasing HDL has not been shown to be effective in reducing the risk of heart attack. In fact, a clinical trial involving a medication aimed at increasing HDL levels revealed an increased the risk of heart attack when HDL levels became excessively high.

What has been proven helpful in predicting the risk of heart attack among the commonly conducted tests in Singapore are LDL (often referred to as bad cholesterol) and the non-HDL level (calculated by subtracting HDL from total cholesterol). If these levels fall within the most ideal range for you, there is no need to be overly concerned.

Higher HDL levels are also associated with a healthy lifestyle, which includes factors such as your diet and exercise habits. Do not forget that these lifestyle factors also play a significant role in lowering your risk. You can read more about the heart healthy diet here: https://www.nhcs.com.sg/news/stories-from-the-heart/blog-article-for-patients-diet-for-cardiovascular-disease-risk-reduction. We will also be adding a Mediterranean diet article soon, stay tuned to our NHCS website for that!

14. Question by CS Chew

Hi Dr,

What is the most comprehensive/effective cardiology check on the health of my heart? I have seen some friends who gone on health checks including heart but still had cardiac arrest and block in arteries gone undetected. Thanks.

Answer by Asst Prof Huang Zijuan

Dear CS Chew,

This is a common concern from some of my patients too. Let me break it down for you.

Firstly, it is important to note that all tests have their limitations and to assess the benefits versus risks (also known as risk-benefit ratio). There are different tests which may be more suitable for different patients to achieve the best risk-benefit ratio. Tests used to check for coronary artery disease are not without associated risks, for example there are risks of radiation in some scans, hence we would want to be judicious and choose it for those who do have good indications for it. There are other tests which might involve risks of heart attack, stroke, abnormal rhythms etc. Hence, there is no single best test for the various patient profiles.

Next, let's consider a scenario where you had a test done for valid reasons. For instance, if you underwent a CT coronary angiogram and it revealed a plaque deposit (a fatty blockage primarily composed of cholesterol deposits and occasional calcium and fibrous deposits) in one of your coronary arteries, which was only causing mild blockage. This would not warrant any invasive treatment, such as coronary stenting or bypass surgery which have their own risks.

In fact, many of us to certain extent, have some deposits in our arteries depending on what risk factors we have. It was found that as young as 3 year olds, could start having fatty streaks in their arteries. Therefore the question is whether it will get worse and lead to a heart attack.

While a scan may reveal minor coronary artery deposits, it does not guarantee that a heart attack will not occur too, as the original plaque can change and there is also risk of new plaque in new areas. Hence whether there are changes in a positive or negative direction, it is dependent on how well the risk factors are managed. Poor control of risk factors such as smoking, high bad cholesterol levels, sedentary lifestyle, and unhealthy diet (high sugar, excessive processed foods and meats, saturated fat and minimal greens) can lead to higher risk of getting heart attack.

Therefore, the best protection for everyone is to achieve our cardiovascular risk factor targets. An acceptable result now does not guarantee that a heart attack will not occur in future.

What are the targets to take care of? For a start, work on managing your cholesterol, blood sugar and blood pressure levels, and setting an exercise regime (type, duration and frequency) and watching your diet. Importantly, quit or no smoking. Please consult your doctor for specific details on how to better manage your risks and know your health targets according to the other risk factors that you might have.

You may use the heart risk calculator in the Health Buddy app to calculate your current risk based on your risk factors and learn how to make modifications accordingly (for example, if your risk falls in the orange or red range, a risk modification button will appear, to lead you to more health resources/information).

15. Question by Anthony

Dear Asst Prof Huang,

I’ve heart palpitations for the last 2 years. I’m 63 years of age and male. My questions are:

a) My palpitations normally comes in the night when I’m asleep. I will be woken by the heart thumping and disrupt my sleep for few hours. Why does it happen at night?

b) I will need to go to urine frequently, about 5 minutes intervals for several time once the palpitations start. Is the heart and kidney/bladder related?

c) I regularly do long distance running - once or twice a week for 45 mins. Has the running exerted the heart causing the palpitations?

d) Lastly, what should I do to stop this palpitation?

Thank you for taking the time to look into my questions.

Answer by Asst Prof Huang Zijuan

Dear Anthony,

a) The palpitations may be better felt at night when it is quiet or it may be that they tend to happen more when you are resting. Certain types of abnormal rhythms may exhibit this behaviour. It is best to consult a doctor so the appropriate assessment and testing can be done. If you have palpitations causing giddiness, chest pain, breathlessness or even fainting spells, please seek emergency medical attention.

b) This does not sound related to the heart, but rather more urological system related, for example, due to bladder or prostate issues.

c) It is advisable and safer for you to avoid vigorous exercise like long distance running, until your palpitation issue has been fully investigated.

d) Seeking medical attention is advisable, and if appropriate for your condition, medications may be prescribed.

16. Question by Mr Sim

Hi Asst Prof Huang,

I had a long stent placed at the heart junction in 2012 but since 2017 I have been experiencing breathlessness and upper Jaw pain again.

I can pinpoint my pain to a nerve in my tooth (no cavity) that is giving me excruciating pain for about 1 minute simultaneously with the breathlessness.

My question is, do I need a neurologist consultant as my heart breathlessness is not a troubling concern, at least it is easily manageable but not the "Toothache-like" pain. What would your advice be?

Answer by Asst Prof Huang Zijuan

Dear Mr Sim,

Blockages in your heart arteries can present as jaw pain, especially when coupled with breathlessness, like in your case. It is advisable for you to seek early medical attention, and you may be scheduled to see a cardiologist.

17. Question by Viv

Hi Dr,

Recently I felt my heart was beating very fast all-of-a-sudden. I don't feel any pain nor any shortness of breath, but it lasted for about more than an hour continuously non-stop.

This sudden fast heartbeat happened before but usually it last for only a few seconds. But this time round, it's more than 1 hour.

Is this a symptom? Should I go and see a heart specialist about this? Thank you for your advice.

Answer by Asst Prof Huang Zijuan

Dear Viv,

This sounds like an abnormal heart rhythm issue. You should visit a polyclinic or a GP clinic for an initial assessment, after which you can be referred to see a cardiologist if needed.

If palpitations become associated with dizziness, fainting, breathlessness, or chest pain, do not wait for your appointment; instead, call 995 for an ambulance and go to the emergency department.

18. Question by Al Mlsa

Dear Dr,

I have done a couple of annual check-ups including treadmill and scan. I do this because sometimes I do have chest pains but test results confirm that its only my chest muscle.

How do I know when this is beyond my chest muscle? What are the symptoms and indicators? I do have a family history of heart disease with my late father, who has gone through bypass surgery.

My cholesterol is currently under control with statins and my BP with Cozaar. Thank you for your advice.

Answer by Asst Prof Huang Zijuan

Dear Al Mlsa,

Cardiac-origin chest pain is typically more persistent, lasting for at least 5 to 10 minutes, and it does not usually manifest as a brief, seconds-long stabbing pain (which is more likely to be musculoskeletal in nature). Additionally, cardiac chest pain tends to occur during physical exertion.

There are several factors to manage to have effective control of your heart artery disease risk.

For a start, work on managing your cholesterol, blood sugar and blood pressure levels, and setting an exercise regime (type, duration, and frequency) and watching your diet. Importantly, quit or no smoking. Please consult your doctor for specific details on how to better manage your risks and know your health targets according to the other risk factors that you might have.

You may use the heart risk calculator available on the SingHealth Health Buddy app to calculate your current risk based on your risk factors and learn how to make modifications accordingly.

Ref: I23