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Putting People to the Test Before They Exercise : While strenuous activity may not kill a person, ignorance might. Doctors have a variety of ways to evaluate risk factors.

KEEPING FIT

August 25, 1992|PATRICK MOTT | SPECIAL TO THE TIMES

Jim Fixx had iron legs and leather lungs and could run a deer to ground, but every step he took brought him closer to an almost instant death at the age of 52. He was stricken by a heart attack because he didn't heed his own advice.

In the late 1970s, Fixx was the guru of American running. His jogger's primer, "The Complete Book of Running," has been variously credited with igniting the running revolution and inspiring millions to get out and pound the pavement.

As expected, the book included an admonishment to the sedentary and the out-of-shape who dreamed of becoming marathoners: Before you start on a strenuous exercise program, get your doctor to check you out.

Fixx didn't. Though he acknowledged his family's troubling history of heart disease--his father had a heart attack at 35 and died eight years later--Fixx never took a diagnostic test that has now become commonplace--a treadmill stress test. Had he done it, the exercise electrocardiogram would have revealed the massive coronary artery blockage that eventually killed America's most famous recreational runner.

Fixx's death, while running along a Vermont highway, frightened many runners right out of their Nikes and back onto the couch, but it needn't have. They would have done better, said Dr. Alan Borsari, to step onto their doctor's office and onto a treadmill. Strenuous exercise, he said, may not kill you. But ignorance might.

"I think it's human nature, generally in older men rather than women, to ignore reality and hope the reality will go away," said Borsari, the medical director of cardiac services at St. Jude Medical Center in Fullerton. "The right attitude, and it's hard to instill, is that risk factors may be there whether you show it or not."

Risk factors. They are what can rise up to smite you during your exercise program if you don't know you have them and in some cases the only way to find out if you're affected by them is to visit the doctor.

Some of these risks are obvious: overweight, smoking, high stress, lack of exercise and a family history of heart disease. Others, such as high blood pressure and the presence of coronary disease, high cholesterol or obstructed arteries can only be revealed by diagnostic tests.

"I think anybody over 30, particularly if that person has two or more risk factors, ought to be evaluated before initiating a strenuous aerobic exercise program," said Borsari. "And \o7 anyone \f7 over 40 ought to."

Most of the tests may be familiar: a blood cholesterol work-up, a thorough physical exam and a compilation of personal physical and family history. It is the stress electrocardiogram that may be the most unfamiliar, and potentially the most telling. It is the diagnostic tool, said Borsari, that answers the essential question, "Have any of these risk factors caused enough problems to put that patient at risk?"

The most common such test is the treadmill. After sensors are attached to the patient's chest and shoulder areas, he begins to walk on the moving treadmill. His blood pressure is regularly monitored and the sensors pick up the speed, intensity and pattern of his heartbeat. Also, the volume of blood flow to and from the heart is picked up.

The test is designed to work the heart for a time near the patient's target heart rate, which is generally acknowledged to be 220 minus the patient's age. To reach that point, the treadmill is speeded up at intervals and is canted upward to simulate an uphill walk or run.

There are other forms of stress EKGs. The thallium stress test is similar to the treadmill test with the extra step of injecting a radioactive isotope into a vein, which travels to the heart and forms a "picture" of the heart and its function that can be photographed. The stress echo test involves introducing ultrasound waves into the chest cavity which are then "read" by instruments, giving a video picture of the heart in motion (the entire Los Angeles Rams team undergoes this test at the beginning of each season, said Borsari).

The treadmill is the least expensive of the tests, but also the least accurate in predicting inadequate coronary blood flow. It has, said Borsari, an accuracy rate of between 60% and 70% and generally costs between $200 and $300. The thallium and stress echo tests are accurate between 85% and 90% of the time, but cost between $700 and $900.

The use of each type of EKG depends on the condition of the patient or evidence of previous symptoms, as well as on the doctor's discretion, said Borsari. If a patient with symptoms of coronary artery disease showed no abnormality during a treadmill test, he might be referred on to a thallium or stress echo test, said Borsari.

The newest heart test being performed, said Borsari, is called the "fast CT scan." Not yet in wide use, the computerized tomography scan takes a picture of the heart and produces an image that is highly sensitive to calcification--the plaque on artery walls that signal atherosclerosis.

It is, said Borsari, highly accurate, but there's a catch: "It tells you that there's a problem, but it doesn't tell you how bad the problem is." A test costs about $250, but the necessary equipment may be hard to find.

However, said Borsari, the type of stress EKG that is performed "isn't as important as simply \o7 doing \f7 one of them. Because you can control your smoking, you can control your high blood pressure, you can control your cholesterol, but what your dad might have had is unfixable. But when you start to control your risk factors, you can slow, stop or even reverse coronary disease."

Exercise? Absolutely, said Borsari. But maybe your first training run ought to be on a treadmill.

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