Implementation and Integration of Prehospital ECGs Into Systems of Care for Acute Coronary Syndrome

Clinical case: A 58-year-old woman called 9-1-1 with acute onset of chest pain that had persisted for 30 minutes. She had a history of hypertension, hyperlipidemia, and type 2 diabetes mellitus but no previous history of myocardial infarction or heart failure. Her medications included aspirin, atorvastatin, lisinopril, and metoprolol. Paramedics were dispatched, and a prehospital ECG demonstrated 3- to 4-mm ST-segment elevation in leads I, aVL, and V2 through V6 (Figure 1). Her examination revealed a regular pulse of 90 bpm, a blood pressure of 100/60 mm Hg, clear lungs, and normal heart sounds with no murmurs. Paramedics interpreted the prehospital ECG and activated the catheterization laboratory en route to the hospital. On hospital arrival, the patient was transported directly to the catheterization laboratory. Coronary angiography demonstrated an occluded proximal left anterior descending artery, which was successfully treated with balloon angioplasty and a stent. The pertinent time intervals were as follows: paramedic dispatch to balloon time, 56 minutes; paramedic arrival at the scene to balloon time, 46 minutes; hospital door to balloon time, 23 minutes. Her biomarkers revealed a peak troponin T of 2.42 ng/mL and a peak creatine kinase muscle-brain isoenzyme of 26.8 ng/mL. An echocardiogram demonstrated normal left ventricular ejection fraction of 55%, with mild anterior hypokinesis, and the patient was discharged on hospital day 3. Figure 1. Prehospital ECG.American Heart Association national guidelines,1–3 as well as other consensus and scientific statements,4–11 recommend that emergency medical services (EMS) acquire and use prehospital ECGs to evaluate patients with suspected acute coronary syndrome. Despite these recommendations, prehospital ECGs are used in fewer than 10% of patients with ST-segment–elevation myocardial infarction (STEMI),12,13 and this rate has not substantially changed since the mid-1990s. Furthermore, even when a prehospital ECG is acquired, the information is often not …