I suppose she may have Prinzmetal's angina or microvascular angina. A stress test would not necessarily help sort this out. There are sophisticated sorts of measurements that can be made during a cardiac catheterization to provoke spasm or to assess the microcirculation done at referral medical centers. If her doctors feel that a more definitive diagnosis needs to be made, this type of testing could be pursued. Given her history of pericarditis, this seems like a more likely cause for her symptoms, though it would not entirely explain the abnormal blood work.