Delay in thrombolysis administration: causes of extended door-to-drug times and the asymptote effect.

We retrospectively analyzed medical records and critical pathway data forms of all patients who received thrombolytic therapy for acute myocardial infarction (AMI) over a 2 1/2-year period. The time spent by each patient in the emergency department (ED) prior to receiving thrombolytic therapy (the door-to-drug time) was determined. Records of those patients with door-to-drug times exceeding the median were closely examined to determine the cause of treatment delays. Results indicated that treatment delays resulted from delays in obtaining the initial electrocardiogram (24%), atypical presentations (11%), the need to rule out a potential contraindication (11%), the need to confirm the diagnosis (14%), and miscellaneous causes (8%). Many patients had no identifiable reason for their delay (32%). A certain population of AMI patients either do not satisfy thrombolytic criteria upon initial ED presentation or require prolonged evaluation to investigate possible contraindications to thrombolysis such as aortic dissection. The inclusion of patients in this separate population in a general analysis of median door-to-drug times results in an artificial asymptote effect and may confound quality initiatives.