ekg changes...ehh,, maybe prolonged PR interval, they might think 1'st degree AV block,,,sinus bradycardia( if he is in sinus rhythm), depends on the dose and the patient response...you might want to pm the member who goes by the screen name "swatdoc" . from what i remember on a different post you we worried this would show up on some sort of life insurance/healthcare coverage test. i do know have knowledge of how testing is run for health insurance purposes except to get the COPD patients pulse ox down to 87% so they can be discharge with an order for oxygen.