For years, Mr Chong would become breathless from carrying these 5kg bags of fish. As he has Down syndrome, he could not express his discomfort earlier. Now, he can load and unload the fish easily, after doctors plugged the holes in his heart in 2009. -- ST PHOTO: DESMOND FOO

To mark Congenital Heart Disease Week this week, Mind Your Body finds out why more children are surviving the disease

Children born with heart defects can now expect to live well into adulthood, when they would have died a few decades ago.

As a result, there are more adults living with congenital heart disease now than children.

For example, in 2000, there were an estimated 9,900 people aged 20 and above living with the condition, compared to about 6,100 such children, said Dr James Yip, a senior consultant at the National University Heart Centre, Singapore. He estimates the number of adult patients now is higher, but has no exact figure.

Although they may have outlived expectations, many still need monitoring and face future health complications despite having their heart defects treated as a child.

The National University Heart Centre has treated about 5,000 such adult patients since 2003. About 3,000 are still being followed up, while the rest have either been discharged or stopped treatment for unknown reasons.

They could have chosen to stop going for follow-up checks because they felt well or they might be seeing doctors in other medical centres, said Dr Yip.

The National Heart Centre Singapore has seen the number of adult patients with congenital heart disease rise from about 400 in 2005 to more than 900 last year.

About 0.8 to 1 per cent of babies here are born with congenital heart disease, which can come in many different forms. They usually have structural defects in their heart, such as holes or faulty valves.

But most now survive to adulthood because of medical advances such as better surgical techniques and improved intensive care, said Dr Tan Ju Le, director of the National Heart Centre's adult congenital heart disease programme.

Studies overseas have shown that close to 90per cent of children with congenital heart disease now grow to adulthood, up from just 15 per cent several decades ago.

Up to the 1960s, 'blue babies' - who had severe and complicated heart defects that left them oxygen-starved and literally blue - would not have survived here because no surgery was available to save them, said Dr Yip.

Today, they can be resuscitated and kept alive until they are old enough for open-heart surgery at one or two months of age.

In the last 10 years or so, doctors have been able to close certain holes in the heart by using a less invasive procedure than conventional open-heart surgery, Dr Tan said.

This involves threading a catheter through a vein in the leg to the heart and delivering a mushroom-shaped device to plug the hole.

A National University Hospital (NUH) study published last year showed that children who had the device implanted were in hospital for about two days. This is far shorter than the six days required for those who have open-heart surgery, including at least a day in intensive care.

The study, led by Associate Professor Quek Swee Chye, who heads the paediatric cardiology unit in NUH's University Children's Medical Institute, also found that children with the plug were less likely to develop complications after surgery.

Now both national heart centres have set up special programmes to care for this sizeable pool of adults, as well as train Dr Yip, Dr Tan and two other doctors to take care of adults with congenital heart disease.

Previously, these patients would have been cared for by paediatric cardiologists, or cardiologists not specially trained in congenital heart diseases.

About a third have fairly straightforward heart defects that are unlikely to cause further problems or require further treatment, Dr Tan estimated.

But the rest have moderate to complex conditions that need life-long monitoring and may need further treatment, she said.

For example, a baby whose heart valve was too tight would have had surgery to loosen the valve so that blood could flow more smoothly, said Dr Yip.

But later in life, the valve may become too loose and leak. The patient may then need another operation to replace the leaky valve.

Female patients need special care when they become pregnant or they could die in childbirth from heart problems, he said.

Patients are also at higher risk of infections of the heart, so they are given antibiotics before visiting the dentist or going for surgery as a precaution, he added.

Dr Tan said: 'In the past, congenital heart disease was just a condition of childhood. It was believed that after they are operated on, they are normal.

'But that's not the case. There are residual effects in adulthood, so most survivors will need follow-up checks for life.' 

About 40 to 50% of Down syndrome patients have congenital heart disease 

About 90% of children with congenital heart disease survive to adulthood now

Holes in heart diagnosed only when he was 33
Mr Chong Boon Teck, 35, had two holes in his heart from birth, which were detected only two years ago.

It was when he caught a lung infection that the congenital defects were discovered.

They might have been found earlier except that Mr Chong has Down syndrome. And though he would be breathless after walking long distances or moving heavy objects, he was unable to express his discomfort.

In August 2009, he came down with a persistent high fever. It was first diagnosed as a symptom of gout, which he suffered from, but it did not subside after treatment.

He was then given an antiviral drug for suspected influenza, but that did not help either.

After almost two weeks, his older sister, Miss Stephanie Chong, took him to hospital after she noticed that he was having trouble breathing.

She recalled: 'His lips and fingers had turned blue and his eyes were rolling upwards. I was frightened.'

A scan showed that he had a lung infection - and two holes in the heart that no one knew about.

Congenital heart disease has traditionally been seen as a childhood disease because many patients are diagnosed and treated before they reach adulthood.

About 40 to 50 per cent of Down syndrome patients have congenital heart disease and newborn babies with genetic disorders are usually screened for heart defects, said Associate Professor Quek Swee Chye, who heads the paediatric cardiology unit in National University Hospital's University Children's Medical Institute.

But Mr Chong's heart defects may have been 'silent', meaning he had no symptoms, and were therefore missed, said Prof Quek.

Babies with some types of serious and complex heart defects appear blue at birth from a lack of oxygen and these will not be missed, doctors said.

Dr Tan Teng Hong, senior consultant of the cardiology service at KK Women's and Children's Hospital, said all newborn babies are checked before being discharged.

During such a check, doctors may detect heart defects if they hear a heart murmur, pick up an abnormal pulse or observe bluish discolouration of the skin, he said.

These symptoms may surface later and be picked up by family physicians or paediatricians or through school health screening, he added.

After Mr Chong recovered from his infection, he had a procedure to correct his defects in December 2009 at National Heart Centre Singapore.

Dr Tan Ju Le, the director of its adult congenital heart disease programme, plugged a 2.1cm-wide hole - the larger of the two holes - with a device inserted through a catheter threaded along his leg vein to his heart. The top of the mushroom-shaped device also partially covered the second hole, which was 0.8cm wide.

His tissue has since grown over the device, sealing both holes. The right chamber of his heart, which had become enlarged due to the holes, is back to its normal size.

The oldest patient who had this device inserted at the National University Heart Centre, Singapore was 80 years old.

Mr Chong can now walk at a faster pace without having to sit and rest frequently.

He can also load bags of tropical fish, bred for export on his family farm and weighing up to 5kg each, onto lorries.

Miss Chong, 43, who runs the family business, said: 'Previously, when it came to loading and unloading the fish, he refused to budge from his seat. Now he just rushes to do it on his own.'

Source: The Straits Times © Singapore Press Holdings Limited. Permission required for reproduction.