Singapore - What you need to know and do in a heart attack

Here's the bad news:

Heart attack kills! Worldwide in 2008, 7.3 million people died from heart attack.

In Singapore, heart attack is the number 2 killer accounting for 18.7 per cent of deaths, i.e. approximately 1 in 5 deaths is due to heart attack, according to data from 2010 Singapore Health Facts.

Here's the good news:

Heart attack is treatable condition. If medical attention can be given early, it is potentially life-saving. You can save your life or somebody else's, if you know how to.

Modern, prompt, efficient medical treatment can save and greatly improve your chances of surviving a heart attack

The first and foremost important step in treating a heart attack is your own recognition that you may be suffering from a heart attack.

The key to successful treatment is for you to recognise the symptoms and signs of an impending heart attack and for you to seek early treatment.

Sadly too many people with heart attacks attribute the symptoms to something else or simply hope that the symptoms will disappear. This puts them at an immediate disadvantage for effective treatment and survival.

Almost 50 to 60 per cent of people who die from a heart attack do so within the first hour after the onset of symptoms before medical help is sought or can reach them

What is a heart attack?

A heart attack occurs when one of the blood vessels (known as coronary arteries) that supply oxygen and nutrients to the muscles of the heart is suddenly blocked off.

The mechanism of blocking-off a coronary artery is due to a rupture of a cholesterol plaque which has been building up in the coronary artery.

The plaque rupture exposes the cholesterol material to the circulating blood with the resultant formation of a blood clot that blocks the channel of the coronary artery leading to a loss of blood supply, oxygen and nutrients reaching that portion of the heart muscles.

If the blood supply is not reestablished and left shut out long enough (usually between 30 minutes to 2 hours), there will be irreversible muscle damage and loss of function, i.e. the inability of the heart muscles to contract.

If the muscle damage is extensive enough, the heart will stop, resulting in death. Heart attack usually occurs very suddenly.

When a heart attack occurs there are many consequences, as listed below:

What are the consequences of a heart attack?

The immediate consequences of heart attack are usually due to life-threatening abnormal rhythms. The commonest and the worst heart rhythm is called ventricular fibrillation .

During an acute heart attack, the heart muscles are damage and the electrical circuits of the heart go into a disarray and instead of the heart having a regular pumping action, there is a loss of contraction because the muscles just quiver (fibrillate) without any effective contraction.

This usually result in the loss of effective pumping action of the heart to deliver blood to the whole body.

The heart attack victim usually will collapse due to loss of blood supply to the brain and the body within seconds and if no medical attention to reverse this process, brain damage and brain death will issue within two to four minutes from the time of collapse.

Thereafter the success rate of reviving the victim is remote. It is known that at least 50 per cent of heart attack victims will not be able to get medical attention or reach the hospital in time for the doctors to treat this condition.

A second heart rhythm that potentially can be life-threatening is called complete heart block .

In this condition, the heart is unable to pump due to the inability of the heart's own pacemaker to initiate the heart beat to travel from the upper chambers to the lower chambers via connecting electrical circuits.

This again can result in a slowing of the heart pump with reduced blood supply to the brain and the rest of the body.

Finally if delays in medical treatment are inevitable, within the next two to three hours the bulk of the muscles of the heart will die and so even if the victim survives the heart attack, the heart function will be reduced significantly and this will lead to heart failure and also a shortening of one's life span.

From the above it can be clearly seen that it is important that the public as well as the victim should recognize an impending heart attack and also know what to do when this happens.

How do you recognise a heart attack?

Recognition of early symptoms and sign of a heart attack is the key to saving a life. Bear in mind that heart attack is a medical emergency.

Chest pain is usually the most common presenting symptom. The chest pain is usually sudden in onset and severe in intensity.

The pain is usually described (see table below) as severe crushing pain, constricting of the chest not dissimilar to a "bear hug", vise-like grip, strangling, feeling like a heavy weight on the chest.

The pain is usually associated with generalized profuse sweating (described as cold sweats) associated with difficulties in breathing.

There is sense of impending "doom". The pain is usually located in the centre of the chest behind the breast bone.

However the chest pain may also radiate to the neck, lower jaw, the left shoulder and arm.

Occasionally it could mimic gastric pains which is located at the lower chest and the upper abdominal area. The face of a heart attack victim looks "ashen", pale and lips appear white.

How to recognize a heart attack : Chest Pain

Chest pain typically described by victims of heart attack	Chest pain that are unlikely and not typical of a heart attack
· Severe, constricting · “Bear hug” · “Vice-like” · Crushing · Feeling like a heavy weight on chest · Strangling · Heaviness · Squeezing · Burning · Like indigestion · Severe ache · Coldness with profuse sweating · Duration of chest pain is continuous lasting 5 to 10 minutes or more · Radiation to neck, lower jaw, shoulder, arm (especially left side)	· Brief, sharp pain, needle-like pain typically located in a small, specific side of the chest wall · Lasting only a few seconds · Related or aggravated by movements of the chest, especially deep breathing “catches”

This is to be differentiated from other atypical non-cardiac chest pain which is usually described as brief, sharp, poking, "needle-pricking" kind of pain, lasting only for a few seconds and located in a small area of the chest.

This kind of pain is rarely due to heart attack. In addition chest pain which is related to or aggravated by chest movements as well as deep breathing are also not classical of heart attack chest pains.

The reason to try and differentiate this is to prevent unnecessary alarm, and concern and unnecessary visits to a doctor or a hospital. Look for other associations that may lead one to consider a heart attack :

1) Age - usually middle to elderly men, young women are less likely to experience heart attack (although not excluded)

2) History of high blood pressure, high cholesterol, diabetes mellitus, smoking

3) Obesity

4) Ethnic origin - Indians (known to have 3x more prevalence of heart attack in Singapore compared to Chinese and Malays) 

5) Obviously known history of coronary heart disease

6) Genetic predisposition, i.e. a close relative (mother, father, brother or sister) who developed coronary artery disease or sudden death before the age of 55

What you, your family or friends can do in a heart attack

The first thing is to rest the victim comfortably in a sofa chair or on the bed. Immediate alert for ambulance service or for a medical assistance is priority.

If there is availability of household medications like Aspirin, this can be given, usually 100 to 300 mg of Aspirin.

Some who already have medications for treatment of coronary artery disease should use them.

Most important is a medication called glyceryl trinitrate. This can be administered as sublingual (under the tongue) tablet or as a spray or a dermal patch.

A patient who is suspected to have a heart attack should get to the hospital as soon as possible.

As mentioned above, there is a time window of about two to three hours before the heart muscles are irreversibly damaged.

A heart specialist can salvage the heart muscles to prevent extensive damage when he can be reached within the time window.

What to know at the hospital

The heart victim will be identified immediately and rushed to the coronary intensive care unit where several tests including a 12-lead ECG, cardiac enzymes (CK-MB and cardiac Troponins) will immediately confirm the diagnosis of a heart attack.

The patient will be administered blood thinning medications and will be rushed to the coronary interventional lab and undergo an immediate procedure called coronary angiography.

In the cardiac catheterization lab, an interventional cardiologist will perform a procedure called coronary angiogram to visualize the status of the coronary arteries so as to determine which artery/arteries are acutely blocked off by clots.

This usually takes less than five to 10 minutes to do and once this has been determined, the effective way to save a heart attack patient is to deliver an aspiration catheter to suck out the blood clot at the site of the blockage and then to follow by the deployment of a stent (which is a metal scaffolding) to hold and support the artery up.

Immediately when this has been completed, the blood supply will return to that portion of the muscles of the heart and thus providing oxygenation and nutrition to the muscles.

In this way the heart attack is aborted and the amount of heart muscle damage will be minimised. There is almost immediate relief of the severe chest pain as well as stabilization of the patient.

The victim will stay in the hospital for three or four days more and will then be discharged with blood-thinning medications to prevent further clot formation.

He or she will also be given a series of medications to reduce cholesterol and to improve the function of the heart.

As can be seen from the above, it is therefore mandatory to be able to identify a heart attack victim and to bring him or her to the hospital urgently as time is of the essence.

It has always been mentioned that in a heart attack, "time is muscle." This means, the earlier you seek treatment to establish the blood supply to the heart, the more muscles you will save and therefore the better will be the final recovery of the function of the heart and outcome.

This method of treatment has revolutionised treatment of heart attack patients.

In the past, when this was not available, most patients would be just treated medically and to "ride-out" heart attack, which means to say substantial amount of heart muscles will be damaged, leading to a dilated heart with reduced function and therefore potentially heart failure and shortening of life span.

Where do you find this form of treatment of heart attack?

Most of the tertiary hospitals in Singapore have the capabilities of doing an acute coronary angiogram and clot aspiration followed by deployment of coronary stent(s). This will include the following:

In the private sector:

1. Gleneagles Hospital

2. Mt Elizabeth Hospital

3. Mt Elizabeth Novena (tentative date of opening, July 2012)

4. Raffles Medical Hospital

5. Mt Alvernia Hospital

Within the restructured hospital system:

1. Singapore General Hospital - Singapore Heart Centre

2. Changi General Hospital

3. National University Hospital

4. Tan Tock Seng Hospital

5. Khoo Teck Puat Hospital

How to prevent recurrent heart attacks?

As mentioned above the mechanism of a heart attack is due to the rupture of cholesterol plaque(s) within the coronary arteries that supply the heart.

Cholesterol plaques build up over many years. Studies have shown that cholesterol plaques build-up in the coronary arteries can begin as early as childhood and progress to adulthood.

The risk of developing cholesterol plaques in the coronary arteries are accelerated with the following coronary risk factors :

a. High blood pressure

b. High cholesterol

c. Diabetes mellitus

d. Obesity

e. Smoking

Medications should be given if the survived heart attack patient has the above associated risk conditions.

There should be regular follow-up with a heart specialist or a general practitioner to monitor the goal targets that are required. Importantly as far as cholesterol is concerned, the surrogate measurement is LDL i.e. the bad cholesterol.

This should go below between 70 to 80 mg/dl (once a patient has suffered a heart attack).

His/her blood pressure should be maintained at about 130/80 mmHg and he/she should be continuously on blood thinning medications that will include Aspirin as well as another blood thinning medication called Clopidogrel (some newer substitutes are also available).

This dual blood thinning medications should be continued between three to six months depending on the type of stent that was deployed.

Thereafter one of the blood thinning medications can be taken off and the patient should remain on at least one blood thinning medication for the rest of his or her life.

For the reduction of the LDL cholesterol, the most commonly used medication are the statins.

This must be dose-titrated to achieve the target level that has been described above.

Other important cardiac medications include angiotensin coverting enzymes inhibitors (ACEI) and beta-blockers.

Obviously still the most important of all is to live a healthy lifestyle which will include proper balance and healthy diet and also cardiovascular exercises and weight reduction to ideal body mass index if the patient is overweight or obese.

Goals to achieve:

1. Maintain ideal body weight (BMI 18.5 to 24.9 kg/m2)

2. LDL-C < 70 mg/dl 3. BP = 130/80 mmHg

4. Healthy diet - low in cholesterol/trans fat and carbohydrates

5. Regular cardiovascular fitness exercise

6. Medications - Aspirin/clopidogrel/ statins/ACEI/betablocker

7. If diabetic - HbA1c 6.5 per cent to< 7 per cent (fasting blood sugar < 7.0 mmol/L or 126 mg/dl); ideally < 6.0 mmol/L or 108 mg/dl

8. Smoking cessation

9. De-stress programmes

Conclusions

Just 25 years ago, when a patient is seen at a hospital with a heart attack, the best that could be done was to put the patient in a comfortable, quiet room, give him or her morphine for pain and some medications to prevent dangerous irregular heart beats and "hope for the best".

Today treating a heart attack is all about speed.

Speed to get the patient to the cardiac cath lab, so that the clot that blocks the life-saving flow of blood can be "busted" by mechanical aspiration or drugs and deployment of stent (tiny flexible struts) to prop open the blood vessel and to restore normal blood flow.

Remember: A heart attack is a medical emergency.

It is of utmost importance to re-read table on page three on chest pain.

Remember that if chest pains last continuously for five minutes or longer and does not respond to nitroglycerin (if this medication has been prescribed for you), you must seek medical attention immediately.

This article was contributed by Dr Peter Yan, Medical Director of Parkway Heart and Vascular Centre, and Consultant Cardiologist at Gleneagles, Mt Elizabeth and Mt E Novena Hospitals.

YourHealth, AsiaOne