Sudden Physical Exertion May Harm Heart Patients

NEW YORK (Reuters Health) - Sudden increases in physical exertion appear to activate clotting factors in the blood of patients with coronary artery disease, indicating that physical exercise by these individuals should be regular and consistent, according to a new report.

Previous studies have shown that sudden, short-term physical exertion can activate coagulation mechanisms in healthy people and patients with coronary artery disease, the authors explain, but such studies have used testing not available to most patients.

Dr. Gregory Y. H. Lip from University Department of Medicine, Birmingham, UK and colleagues investigated whether the incremental shuffle walks test (ISWT), a standardized walking test, adversely affects blood markers of cell damage and dysfunction, coagulation factors, and blood viscosity in 53 patients with coronary artery disease and in 10 matched healthy controls.

Before testing, the patients had significantly higher concentrations of blood clotting factors than did controls, the authors report in the medical journal Heart. Immediately after ISWT, patients had significantly increased levels of clotting factors, the results indicate.

In contrast, the researchers note, healthy controls experienced significant increases in clotting factors only immediately after the ISWT. Increases in some coagulations components were also significantly lower in healthy controls than in coronary artery disease patients.

"We need larger studies," Lip told Reuters Health, "but regular consistent exercise is better than a sudden exertional stress in sedentary individuals."

Blood clotting "underlies most cardiovascular conditions, and understanding the pathophysiology may help us develop new management strategies," Lip added. "We have ongoing studies investigating the effect of mental and physical stress on (the balance of blood components) in different cardiac diseases."

SOURCE: Heart, November 2005.