The Heart of a Runner

Jan. 3, 2007

Peter Moore was used to pushing himself. An avid athlete, he’d run two marathons, climbed to the top of the Grand Tetons, and regularly biked for hours in the hills near his home. But in 2002, Moore was three miles into a 30-mile bike ride when something felt wrong. “I would try to crank up the speed, then become completely exhausted and have to slow down,” he says. “I’d go again, but it quickly became clear that I was fighting against something that wasn’t going to let me get through.” Moore, then 46, chalked up his fatigue to some kind of exercise-induced asthma. A few days later he visited a doctor, and found that one of the two arteries at the top of his heart was 99 percent blocked.
As Moore did, you probably assume that your heart is in pretty good shape. But that cardiac complacency could be your downfall: In 2004, about 1.2 million Americans discovered their heart problems when they had a heart attack -- and 502,000 of those died. “Even though exercise reduces the risk of heart disease, it isn’t a panacea,” says Paul D. Thompson, M.D., a runner, cardiologist, and director of the Athlete’s Heart Program at Hartford Hospital in Connecticut.

KNOW YOUR NUMBERS
In fact, fitness should be just one aspect of your preventive health approach. “It’s also crucial to know your numbers and keep them at a healthy level,” says Tim Church, M.D., medical director of The Cooper Institute in Dallas. That means: blood pressure should be lower than 120/80; HDL (“good”) cholesterol above 50; LDL (“bad”) cholesterol lower than 100; triglycerides lower than 150; blood glucose level lower than 100; and waist circumference less than 35 inches for women and less than 40 inches for men. These factors plus your family history are key to understanding your overall cardiac picture.
Moore’s weight and cholesterol levels, for example, were right on target. But his father had suffered a fatal heart attack at age 52 while running, so his risk for heart disease was relatively high.
Prevention also means scheduling a checkup (including a blood test, blood pressure check, and a sounding of your heart) with your family doctor every year or so, to stave off any problems before they start.
And although runners are used to training through discomfort, ignoring any of the symptoms of heart trouble, such as tightness in your chest, dizziness or fainting, unusual shortness of breath, even heartburn, is inadvisable. As Dr. Thompson says: “He who has himself for a doctor has a fool for a patient. If you suspect something, get it checked out immediately.”
While atherosclerosis (narrowing of coronary arteries) is the problem that most people associate with heart disease, there are other cardiac conditions that athletes, par-ticularly those over 40, should be aware of.

Arrhythmia
An arrhythmia is a change in the sequence of the electrical impulses that cause your heart to beat. Four million Americans have the condition, according to the American Heart Association.
“Most arrhythmias aren’t serious,” says cardiologist John Randolph Backman, M.D. “It’s when you start stringing multiple beats together that you can get into trouble.”
These so-called sustained arrhythmias can make the heart beat too slow or too fast, or erratically, leading to stroke or heart attack. Though runners with atherosclerosis and high blood pressure are at greatest risk for sustained arrhythmias, even athletes with no discernible danger can be susceptible, especially during runs of 15 miles or more.
“On long runs you can become significantly dehydrated, leading to changes in the blood’s levels of potassium, magnesium, and calcium,” Dr. Backman says. “These chemicals play a vital role in starting and conducting electrical impulses in the heart.” Which makes the following hydration guidelines all the more important: Drink 16 ounces of sports drink two hours before a long run, eight ounces every 20 minutes during your run, and 16 ounces of sports drink afterward.

Myocarditis
Also known as inflammation of the heart, myocarditis is caused by a viral infection that damages the valves, the tiny “doors” that open and shut to allow blood to flow through the heart’s four chambers.
Although the condition isn’t very common, weekend atheletes still need to be careful if they’ve had any viral infection (including the flu) that makes muscles ache.
“Your heart is a muscle, so if your muscles are sore, your heart may be involved,” Dr. Thompson says. “Rest until your muscles aren’t aching. When you return to exercise, if you find that you just can’t run at the levels you used to run, see your doctor. You may have a persistent infection of the heart.”

Valve Conditions
Some valve conditions can be congenital; others become more likely as we age. A defective heart valve is one that fails to fully open or close.
“Leaky valve symptoms can be more insidious and develop more slowly than those of other heart conditions,” says J. Michael Smith, M.D., a cardiac surgeon at Good Samaritan Hospital in Cincinnati. “You’ll just feel a little bit more fatigued and gradually find your workouts more difficult.”
A good doctor can spot a defective heart valve by listening with a stethoscope for a heart murmur, the sound made by the blood circulating through the heart’s chambers.
“Some athletes, because they have such strong hearts and slow heart rates, throw a lot of blood out of their valve all at once,” says Dr. Backman, who recently ran his 100th marathon. “As a result, you’re likely to hear a bit of turbulence, called a flow murmur, which is not necessarily indicative of a problem. A doctor who understands the physiology of runners will recognize this.”
With the blessing of his doctors, Moore still runs regularly, and he’s added interval training and weight-training to his routine to give his heart a more varied workout.
He also no longer views six-mile runs as license to scarf doughnuts. “It’s wrong for people to think that their exercise program conveys some kind of protective bubble around them,” he says. “Running is great exercise, but there can be health-related things going on independently that can bring you down, as happened to my dad, and nearly to me.”


OTher Signals of Heart Hassles


Though cholesterol and blood pressure levels are among the clues doctors use to predict heart disease, they aren’t the only indications of a potential problem. Here are three of the newest additions to the doc’s diagnostic toolbox. A blood test can tell you where your levels stand.

Homocysteine
What it is: An amino acid in the blood.
Why it’s bad: Studies have linked high levels of homocysteine to an elevated risk of heart disease and stroke.
Treatment: Folic acid and vitamins B6 and B12 can break down homocysteine in the body.

C-reactive protein (CRP)
What it is: A naturally occurring chemical in the blood that is elevated when inflammation is present in the body.
Why it’s bad: Inflammation in arteries can make plaque rupture, causing a heart attack or stroke.
Treatment: Exercise can reduce CRP levels by helping restore the function of the inner lining of blood vessels.

Lipoprotein
What it is: A variation of LDL, the “bad” blood cholesterol Why it’s bad: Lipoprotein has been associated with an increased risk of stroke and cardiovascular disease.
Treatment: Diet, exercise, and cholesterol-lowering drugs can lower lipoprotein levels.

A version of this article originally ran in “Runner’s World.”