Paramedic Administered ECGs Speed Heart Attack Treatment

A new study claims that training emergency medical service (EMS) providers to read electrocardiograms (ECGs) expedites the treatment of ST-segment elevation myocardial infarction (STEMI), and should become the new standard of care.

Researchers at the University of Manitoba (Winnipeg, Canada) set out to examine the effectiveness of a system of prehospital ECG interpretation and triage developed in Manitoba (Canada) that trains EMS personnel to administer and interpret ECGs for signs of STEMI. When the EMS technician suspects STEMI, the ECG is transmitted to the hand-held device of the on-call physician for confirmation. When STEMI is confirmed, the physician directs the responders to begin prehospital thrombolysis (PHL) or to alert the primary percutaneous coronary intervention (PPCI) laboratory at the hospital to prepare for the patient.

Transmission of the ECG allows for a real-time conversation between the physician and EMS team, decreases false positive test results for STEMI, and improves resource allocation by decreasing activation of the catheterization laboratory when it is not warranted. The emergency room is bypassed in positive cases, and patients are directly transported to the cardiology department or the PPCI laboratory. In cases in which the physician finds the ECG negative for STEMI, patients are transported to the nearest ER.

The researchers evaluated 380 cases from July 2008 to July 2010. Of 226 patients confirmed with STEMI, 70% received PPCI, 21% received PHL, and 20% underwent coronary angiography without revascularization. The median time from first medical contact to treatment in the PHL treatment group was 32 minutes; in the PPCI group, the median time was 76 minutes. In the group that was negative for STEMI, 41% were directed to a hospital capable of PPCI and 59% were sent to one of the six other hospitals in the system. In all, 44% were diagnosed with acute coronary syndromes, including seven cases of missed STEMI, and a higher mortality rate. The study was published in the July/August 2012 issue of the Canadian Journal of Cardiology.

“It’s well established that morbidity and mortality in myocardial infarctions is directly related to the duration of ischemia, and delays in restoring the flow of blood to the heart of even 30 minutes have been associated with an increase in mortality,” said lead author Robin Ducas, MD. “By training EMS to administer and interpret ECGs at the scene, with oversight from an on-call physician, we demonstrated that we could achieve benchmark times from first medical contact to treatment.”

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University of Manitoba