Prehospital recognition of acute myocardial infarction

Abstract

Paramedics often provide advance notice of patients with suspected acute myocardial infarction (AMI) so that emergency department (ED) staff can prepare for early aggressive management and expeditious thrombolysis, but the validity of this practice is unclear. Our objective was to determine the accuracy of prehospital AMI diagnosis by Paramedic Level III (ALS) attendants. ALS paramedics serving a busy community hospital were instructed regarding the clinical diagnosis of chest pain and the value of early thrombolysis. For all patients transported with a chief complaint of chest pain, they were asked to record an explicit diagnosis of "probable AMI" or "chest pain, other." Prehospital diagnoses were subsequently compared to ED diagnoses. Sensitivity, specificity and predictive values of the prehospital diagnosis for AMI were determined. During the 5-year study period, 1305 patients were studied. Based on clinical features alone, ALS paramedics were 77.8% sensitive and 82.2% specific for the diagnosis of AMI. ALS paramedics can accurately identify patients likely to benefit from early aggressive AMI management. These data have implications with respect to prehospital triage of chest pain patients, "early notification" protocols and future prehospital thrombolytic strategies.