In the mid 1990s, Maine ambulance services started looking at the potential for reading 12-lead EKGs in the field. As the capabilities of cardiac monitors increased, so did state services' interest in providing 12-leads as part of prehospital care. For United Ambulance—a CAAS-accredited, nonprofit paramedic-licensed service operating in the central part of the state—12-lead capabilities were made possible with the purchase of several LIFEPAK 12 monitors in 1999.

     For the next two years, United encouraged 12-leads as part of its cardiac patient care. They were not required, however, and were not always utilized by staff at the two hospitals that jointly owned United, Central Maine Medical Center (CMMC) and St. Mary's Regional Medical Center. During this time courses on 12-lead EKGs were offered to United's paramedics by educators from both hospitals.

     In 2003, coauthor Kevin Kendall, MD, FACEP, began a limited review of United's prehospital 12-leads for accuracy. He also reviewed national literature comparing paramedics', cardiologists' and ED physicians' diagnoses of STEMIs (ST-elevation myocardial infarctions). These studies showed no significant differences in the abilities of these groups to recognize STEMIs.^1,2 On March 1, 2004, Kendall, in conjunction with United, started an 18-month comprehensive 12-lead EKG review focusing on rhythm interpretation and STEMI recognition. A total of 658 12-lead EKGs were reviewed, and the results were outstanding: Paramedics were diagnosing MI patients with a high degree of accuracy, and not even one STEMI had been missed.

     Although paramedics across the country use 12-lead EKGs for diagnosing STEMIs, the majority are required to send or bring a copy of the EKG to the receiving hospital for confirmation. With the recent opening of Central Maine Heart and Vascular Institute (CMHVI) at CMMC, activating the cath lab from the field became possible. The debate then turned to whether United would follow the national trend and transmit EKG data directly to the ED for confirmation, or would allow paramedics to activate the cath lab based solely on their diagnoses of STEMIs in the field. It was at this point that United's experience changed significantly from the rest of the country's.

     United was researching devices that could transmit 12-leads to the receiving hospital, but based on the positive results from Kendall's STEMI review, leaders decided this equipment cost was not merited. With the support of local cardiologists and CMHVI, they decided to allow United's paramedics to activate the cath lab directly from the field, without an accompanying 12-lead EKG transmission.