Unsuspected giant cell arteritis diagnosed at open heart surgery.

A 62-year-old patient undergoing aortocoronary bypass grafting had giant cell arteritis diagnosed by routine aortic biopsy done at the graft insertion site. This finding led to the tissue diagnosis of temporal arteritis and the institution of steroid therapy. In retrospect, vague symptoms of headache and fatigue, which had been attributed to side effects of antianginal therapy, were probably caused by giant cell arteritis. The population undergoing aortocoronary bypass grafting is in an age group at risk for giant cell arteritis. Routine aortic biopsy specimens should be carefully examined with this in mind.