What Causes Low Blood Pressure Along With Rapid Heart Rate?

Hello- My husband is experiencing rapid heart rate of 109-132. BP is low- 90/58. He was just in the hospital because his chest was hurting, and the back of his neck. they ran a million tests and nothing shows a problem with the heart. he is taking an aspirin a day, and since he is suffering from COPD he takes quite a few means we just don t quite know what to think.?