Dr. Stacie Bering: Heart failure or not, exercise still a necessity for healthy life

I suppose we doctors begin to sound like broken records. We’re always telling our patients to exercise. In particular, we push aerobic exercise, like we think it’s the cure for everything, and it darned near is. Aerobic exercise strengthens your heart, your lungs and your muscles and releases those endorphins, producing a legal, drug-free high.

Even when a person has a damaged heart, one that doesn’t work as well as it should, we push aerobic exercise. When, you might ask, does a person get a break from our incessant nagging? You’d think a failing heart would be excuse enough, but not according to research reported in this month’s Journal of the American College of Cardiology.

Nearly 5 million Americans suffer from chronic heart failure. Each year, 400,000 more are added to the list. Heart failure doesn’t mean the heart has literally failed, or stopped beating. Rather, it means the heart can’t muster all the strength it needs to keep up with the body’s demand for fresh, oxygen-rich blood. This can come about from a heart attack that has damaged some of the heart muscle, from blocked coronary arteries, from a damaged heart valve or from chronic high blood pressure.

A person suffering from heart failure has shortness of breath when she exerts herself. This may progress to shortness of breath even at rest, and waking up in the middle of the night gasping for air.

She may have to urinate frequently at night and have trouble lying down in bed because of severe shortness of breath. She may have swelling in her ankles.

When the heart is overloaded, it produces chemicals called neurohormones to help out. One of these chemicals, B-type natriurertic peptide, or BNP, is used as a marker for heart failure.

BNP and the other neurohormones are helpful in the early stages of heart failure: They allow the heart to keep pumping blood to meet the body’s needs. But in the long run, this “neurohormonal imbalance” leads to further heart muscle damage, abnormal heart rhythms, and increased symptoms of shortness of breath and fatigue.

Patients with high levels of BNP are known to have higher death rates. Drug treatments may lower the BNP levels, but not enough.

Here’s where the exercise comes in. We know that a carefully structured aerobic exercise program can decrease symptoms of shortness of breath and fatigue. It makes the heart pump more effectively and improves the cardiac patient’s quality of life.

Does exercise have any effect on neurohormone levels?

Those researchers I mentioned earlier wanted to know what, if any, those effects might be. They followed two groups of cardiac patients for nine months.

One group participated in a training program on an exercise bike three times a week for 30 minutes a session. Their workload was adjusted as their performance improved.

The other group received standard heart failure treatment, but they had no exercise training.

The patients who completed the training improved their fitness, felt better and reported a better quality of life then the nonexercisers. They were able to function better than their nonexercising compatriots.

Those who worked out lowered their levels of three key neurohormones, including BNP, and it is this reversal, the researchers surmised, that led to the improvement in the patients’ symptoms. The key was adjusting the workload, since previous studies where the level of exercise stayed constant did not show the same decrease in neurohormones.

So the exercise accomplished what drugs alone could not: It lowered the levels of neurohormones and restored “neurohormonal balance.”

Following BNP levels may be a way for doctors to monitor the effects of long-term exercise training in their heart failure patients.

What the study doesn’t tell us is whether the decrease in neurohormones translates to increased longevity for patients with chronic heart failure.

There are ongoing studies looking at that question.

Just feeling better is reason enough to jump on the Exercycle. A longer life is icing on the cake.