The Treadmill Test
By Jim Rue
Complaining during a checkup to your general practitioner about pain and tightness in your chest may cause him some concern. If your GP observes you to have shortness of breath or other symptoms, he will probably schedule you for a treadmill test.
Generally referred to as a TMT, the stress-induced electrocardiogram objectively measures the way your heart functions when working under a load. The purpose is to seek abnormalities. Don't be afraid. A treadmill test doesn't hurt, and
whenever the testing shows even the remotest sign that all may not be well with your heart, the test is stopped and you are asked to go see someone else.
How it's Done
It's quite simple for the person being tested. After a baseline blood pressure is recorded, twelve conductive pads with adhesive on them are stuck onto your chest and attached to an EKG (electrocardiograph) via thin wires and clamps.
You are asked to lie quietly while another baseline is established determining a normal signal from the electronic pads. You are then asked to stand up and step onto the treadmill while continuing to wear the blood pressure cuff and the pads. The wires running from your body to the EKG machine make you feel a little like a distributor cap.
The treadmill belt begins to move slowly and a belt of white paper winds out of the EKG machine, showing pulses from various parts of your heart. Everything is recorded, including your speed, the elapsed time at each speed, etc. Repeatedly throughout the test, the technician will ask you to rate the degree of pain and exertion you feel on a 1 to 9 scale, then raise the forward edge of the treadmill to make you feel as if you are walking uphill.
The speed of the belt will increase now and then too. The test can become very strenuous. At the most difficult point you will be running up a 28-degree slope at seven miles an hour. Most people don't make it that far. The test is concluded long before that.
According to Bruce
The much-loved designer of the treadmill protocol used worldwide, Dr. Robert Bruce, died on Valentines' Day, 2004. He did not die of a coronary disease, but of leukemia. He was 87.
The End of the Road
The TMT can end at any moment. The purpose of the test after all is to assess whether there are any signs in your heart function suggesting the presence of coronary artery disease (CAD). If the testing physician notes any abnormal results on the EKG output or blood pressure device, he will end the test and probably schedule you for an angiogram.
A stress test will reveal the symptoms of cardiac disease about two thirds of the time. But TMTs report quite a few false positive results, too. The next step is an angiogram. High-tech, interesting and a little scary, the angiogram is regarded in the medical community as the 'gold standard' for cardiac diagnostics.
