Gettin to the heart of the matter
The Sunday Times - Sunday, 23 June 2002

More than 3,200 people died from heart-related failures last year, making heart disease the No 2 killer here, after cancer. But you do not have to be old or fat to start taking care of your heart, reports ICON BOON PIN.

THE thought of doing a "nuclear imaging stress test" thrilled me. At least, I was thrilled until the doctor told me that I would have to receive an injection. "No problem," I said with veneer-thin bravado, as he inserted a small plastic cannula - a small tube - into a vein at the top of my hand. Through this cannula, he injected a radioactive chemical, all this while answering my questions about heart disease without missing a beat.

Moments later, I was telling him I felt light-headed. As a doctor who is used to such reactions, consultant cardiologist Ho Kheng Thye disappeared into the next room and reappeared seconds later with a sweet in his hand. "Take this," he commanded, then he disappeared again to get me a Milo. I thought it might have been the radioactive chemical but, apparently, it was probably a combination of not having had any breakfast and getting "excited" over the injection.

The chemical which was injected into my hand was to aid in the scanning of my heart, in what is called an "exercise stress myocardial perfusion imaging test". Basically, the test assesses the blood flow to the heart muscles during exercise and the strength of the heartbeat.
For people whose blood vessels are narrowed because of smoking, unhealthy diets and stressful lifestyles, blood flow to the heart is usually im
peded during physical exertion.

This is why the test is done in two parts - one to scan the heart at rest, and the other, when the heart is stressed. Designed to produce more sensitive and accurate results than an ordinary treadmill test, the technique relies on scanning done by a gamma camera. This camera rotates around the chest and, in less than 15 minutes, takes 62 images of the heart at various angles.

A composite of these images is then ca tured on a computer as a tree-dimensional image of your heart. The second part of the test took place hours later and required me to walk and run on a treadmill. My initial "this-is-too-easy" comments faded with each passing minute as the speed and incline of the machine increased every three minutes. The purpose of the physical exertion is to get your heart stressed to the point where it reaches your target heart rate. After that, the doctor does a second scan.

Patients who cannot run for various reasons are given another injection to stress the heart without exercise. Comparisons of blood flow to the heart at rest and when stressed will then show up any areas of blockage. My results came back "normal", which means my chances of having a heart attack within the next 12 months are less than 1 per cent. "But that does not mean zero," Dr Ho stressed. "Blockages don't happen overnight. They take many years to develop, starting from one's teenage years. That's why we have to look after ourselves from when we're young," he said.

The nuclear imaging scan was one of five tests I took in the course of a day at the Na- tional University Hospital's Cardiac Centre. While I passed all the tests, even prompting consultant cardiologist Tan Huay Cheem to comment at one point that I had "a beautiful heart", one test did reveal that I had a mitral valve prolapse which I was not aware of previously. Though considered benign, there is a small risk of this valve becoming infected when going through certain surgical procedures if my blood is exposed to bacteria in the air. 

In all, the tests would have cost nearly $1,200 as a private patient ($150 if subsidised), but I guess if you have any kind of medical problem, it's best to find out early enough to do something about it.

At NUS' high-tech Cardiac Centre, ST correspondent Koh HAS his heart scanned by consultant cardiologist Ho