Update On Heart Disease

Exercise may produce improvements in heart tissue.

Description - German researchers looked At a group of 10 patients seeking to determine why exercise aids the ability of blood to supply the heart muscles. The patients did not have classic heart disease, but each had a problem in the function of the endothelium, the layer of cells lining the heart cavity and blood vessels, that is similar to problems often associated with atherosclerosis. The endothelium is important in regulating the dilation of the vessels that provide blood to the heart.

Ten of the patients were hospitalized for four weeks and put on an exercise regimen. That therapy consisted of working out on an exercise bike six times a day for 10 minutes, in addition to a five-minute warm-up and five-minute cool down. The other nine patients served as a control group, were not hospitalized and remained under the care of their private doctors. The researchers found that in the patients who exercised, the endothelial tissue performed better and more blood reached the heart.

What's New - Exercises has long been accepted as lowering the risk of cardiovascular disease, but researchers do not understand the mechanism. This was an effort to look at the physiological changes in the lining of the heart and coronary vessels.

Caveats - The study was extremely small and included only men. Also because the control group was not hospitalized, there may have been differences in diet and compliances in medications. An editorial that accompanies the study points out that the exercise regimen was unconventional and "may not lend itself to application in most cardiac - rehabilitation programs."

Bottom Line - This study tells researchers, long interested in the role of endothelial tissue on heart-disease prevention, that exercise improves the quality of the tissue. It suggests exercise may have additional benefits beyond those already documented.

Find this study - The Feb. 17 issue of the New England Journal of Medicine; and abstract is a available at http://www.nejm.or-g/content /index.asp