What Stress Tests Reveal About Your Heart Health

Your doctor can't tell how well your heart is working until it's put to the test. If you have heart disease—or if you're at risk—your doctor may want to examine your heart during exercise. The stress test can spot hidden problems with your heart and help determine how much exercise you can safely handle.

Kit Cassak, 63, of Scottsdale, Ariz., had had a regular electrocardiogram (ECG or EKG) test in the past, but when she experienced shortness of breath and chest, arm, and jaw pain during physical activity, her doctor referred her to a cardiologist for a stress test. "They hooked up these different electrodes pretty much like an ECG, and they got me to walk on this treadmill, which I'd done during my normal workouts. In less than two minutes they started to see something on their screens and I told them I was feeling symptoms," she says. The cardiologist immediately stopped the test and referred her to the hospital for an angiogram to look for blockages in her blood vessels. The test determined that she needed open-heart surgery.

Who should have a stress test?
Stress tests may be particularly effective for women. Because they don't use radiation, they can be safely used for women who may be pregnant. A recent study by researchers at St. Luke's–Roosevelt Hospital Center in New York City found that stress echocardiograms—a pair of echocardiograms administered before and after exercise—were highly effective in stratifying women into high-risk and low-risk groups for coronary artery disease.

Doctors may also order stress tests after patients have recovered from a heart attack or heart surgery. Mark Miller, 62, of Linden, Calif., put off surgery after having two heart attacks five years ago, but when he failed his fourth stress test, he realized he couldn't wait any longer. "I couldn't go more than one and a half minutes on the treadmill, and the last one, I just collapsed on it," says Miller. Eight months after his heart attack, Miller agreed to have heart surgery. Today he works hard to keep fit and takes an annual stress test. "The last time I went, I lasted for 15 minutes and could have gone longer," he says.