Depression interferes with exercise stress testing

People with depression who have suspected heart disease don't do well on exercise tests, Canadian investigators report.

Symptoms of major depression include lack of energy and fatigue. These may impair exercise performance during treadmill stress testing, and thus interfere with the detection of heart problems, according to a report in the American Heart Journal.

Dr. Kim L. Lavoie, at Hopital du Sacre Coeur in Montreal, and associates examined the differences in exercise testing between individuals with depression and those without. Among the 1367 patients tested, 183 (13 percent) were classified as having major depressive disorder.

Patients with depression performed worse in terms of the maximum heart rate they achieved and total duration of exercise, even after factoring in their age, gender, family history of coronary artery disease, smoking status, and use of beta-blockers.

EKG readings taken during exercise testing showed a lower rate of positive test results in the depressed group than among non-depressed subjects - 30 percent versus 48 percent.

In contrast, however, significantly more participants with depression reported chest pain during exercise - 27 percent versus 19 percent.

"This suggests that patients with major depressive disorder are less likely to perform an adequate exercise test, which may increase the risk of misinterpreting test results and, consequently, bias treatment recommendations in patients who are depressed," the authors conclude.

Lavoie's group recommends depression screening during routine assessments for patients undergoing exercise stress testing.

SOURCE: American Heart Journal, October 2004.