Prehospital Electrocardiography Research Articles

Investigating the efficacy of pre-hospital and in-hospital collaborative treatment platform connected with 120-ambulance in the treatment of patients with acute myocardial infarction

This study aimed to examine the effectiveness of an integrated pre-hospital and in-hospital collaborative treatment platform connected with 120-ambulance in treating patients with acute myocardial infarction (AMI). 114 patients with AMI who were treated at our hospital within one year of the collaborative treatment model’s implementation were selected as the observation group (January 2022 to December 2022). A random selection of 114 cases treated using the conventional model from January 2020 to December 2020 was chosen as the control group. Control patients received conventional treatment, while observation patients received an integrated pre-hospital and in-hospital treatment. Comparisons of effects were made between the two treatment models for AMI patients. The observation group showed significantly lower first medical contact (FMC) to balloon dilation (FMC-to-B), door-to-balloon (D-to-B), and chest pain onset to admission times than the control group. Across both groups, 99.12% of pre-hospital electrocardiography (ECGs) were completed (113/114), and a significantly higher proportion of patients with Killip class ≥II at immediate admission was observed in the observation group (p < 0.05). Observation group showed significantly higher Left Ventricular End-Systolic Volume (LVESV) and Left Ventricular End-Diastolic Volume (LVEDV) than control group (p < 0.05) one month after surgery. The 6-minute walking distance (6MWD) of the observation group was significantly longer than the control group, and the time taken for the 10-meter walking test was significantly shorter (p < 0.05). A significantly lower incidence rate of hospitalization complications occurred in the observation group (p < 0.05). The integrated pre-hospital and in-hospital treatment platform connected with 120-ambulance showed beneficial outcomes for AMI patients, significantly reducing treatment delay, improving postoperative cardiac function, and reducing postoperative complications, making it worthwhile for promotion in AMI clinical treatment.

Cloud-Based Prehospital Electrocardiography May Save More ST-Segment-Elevation Myocardial Infarction Patients in Regional Medical Systems

Cloud-Based Prehospital Electrocardiography May Save More ST-Segment-Elevation Myocardial Infarction Patients in Regional Medical Systems

Association between prehospital recognition of acute myocardial infarction and length of stay in the emergency department.

This study aimed to evaluate the association between prehospital recognition of acute myocardial infarction (AMI) and length of stay (LOS) in the emergency department (ED) of emergency medical service (EMS)-transported AMI patients. A multicenter retrospective observational study was conducted using prehospital and hospital data from three tertiary emergency departments. Patients diagnosed with AMI between January 2015 and December 2018 were enrolled. Study groups were categorized according to prehospital recognition and prehospital 12-lead electrocardiography (ECG) into three groups based on an EMS cardiovascular registry: group A, no prehospital recognition (reference group); group B, prehospital recognition without 12-lead ECG; and group C, prehospital recognition with 12-lead ECG. The primary outcome was an ED LOS of less than 4 hours. Among 1,237 study participants, 722 (58.4%) were in group A, 325 (26.3%) were in group B, and 190 (15.4%) were in group C. Multivariable logistic regression showed that groups B and C had a higher likelihood of a short ED LOS (adjusted odds ratio [95% confidence interval]: group B, 1.64 [1.21-2.22] and group C, 1.88 [1.30-2.71]) than group A. There was no significant difference in ED LOS according to whether prehospital 12-lead ECG was conducted. Prehospital recognition of AMI by EMS personnel, with or without 12-lead ECG, was associated with a short ED LOS.

The influence of ambulance offload time on 30-day risks of death and re-presentation for patients with chest pain.

ObjectiveTo assess whether ambulance offload time influences the risks of death or ambulance re‐attendance within 30 days of initial emergency department (ED) presentations by adults with non‐traumatic chest pain.Design, settingPopulation‐based observational cohort study of consecutive presentations by adults with non‐traumatic chest pain transported by ambulance to Victorian EDs, 1 January 2015 – 30 June 2019.ParticipantsAdults (18 years or older) with non‐traumatic chest pain, excluding patients with ST elevation myocardial infarction (pre‐hospital electrocardiography) and those who were transferred between hospitals or not transported to hospital (eg, cardiac arrest or death prior to transport).Main outcome measuresPrimary outcome: 30‐day all‐cause mortality (Victorian Death Index data). Secondary outcome: Transport by ambulance with chest pain to ED within 30 days of initial ED presentation.ResultsWe included 213 544 people with chest pain transported by ambulance to EDs (mean age, 62 [SD, 18] years; 109 027 women [51%]). The median offload time increased from 21 (IQR, 15–30) minutes in 2015 to 24 (IQR, 17–37) minutes during the first half of 2019. Three offload time tertiles were defined to include approximately equal patient numbers: tertile 1 (0–17 minutes), tertile 2 (18–28 minutes), and tertile 3 (more than 28 minutes). In multivariable models, 30‐day risk of death was greater for patients in tertile 3 than those in tertile 1 (adjusted rates, 1.57% v 1.29%; adjusted risk difference, 0.28 [95% CI, 0.16–0.42] percentage points), as was that of a second ambulance attendance with chest pain (adjusted rates, 9.03% v 8.15%; adjusted risk difference, 0.87 [95% CI, 0.57–1.18] percentage points).ConclusionsLonger ambulance offload times are associated with greater 30‐day risks of death and ambulance re‐attendance for people presenting to EDs with chest pain. Improving the speed of ambulance‐to‐ED transfers is urgently required.

Prehospital point-of-care biomarkers: missing link in acute myocardial infarction?

Coronary heart disease is a leading cause of death worldwide. Paramedics are instrumental in the treatment, triage and transport of patients experiencing acute coronary syndromes and acute myocardial infarction (AMI). Paramedics currently rely on prehospital electrocardiography and patient symptomology to diagnose AMI, which may result in missed diagnoses. Point-of-care biomarkers such as cardiac troponin (cTnT) and copeptin may have the potential to increase the diagnostic capabilities of prehospital providers. Multiple electronic databases (MAG Online Library, Cochrane Library, PubMed and Embase) were searched to evaluate the feasibility and potential application of cardiac biomarkers cTnT and copeptin in the prehospital setting. Because of the paucity of evidence, this article explores the evidence on the dual-marker strategy of cTnT and copeptin to increase diagnostic capabilities of prehospital providers, and as an adjunct for decision-making and risk stratification for AMI. The evidence suggests that using the combined dual-marker strategy of cTnT and copeptin may counteract limitations of the ‘troponin-blind’ period of cTnT and the low cardiac specificity of copeptin. However, the research for this method is still in its infancy and requires investigation into its feasibility and affordability as well as into the training required to implement it in paramedic practice.

Factors associated with emergency medical service delays in suspected ST-elevation myocardial infarction in Victoria, Australia: A retrospective study.

To assess the effect of patient and system characteristics on emergency medical service (EMS) delays prior to arrival at hospital in suspected ST-elevation myocardial infarction (STEMI). This was a retrospective observational study of 1739 patients who presented with suspected STEMI to the EMS in Melbourne, Australia between October 2011 and January 2014. Our primary outcome measure was call-to-hospital time, defined as the time in minutes from emergency call to hospital arrival. We examined the association of patient and system characteristics on call-to-hospital time using multivariable linear regression. The mean call-to-hospital time was 60.1 min (standard deviation 20.5) and the median travel distance was 13.0 km (interquartile range 7.2-23.1). In the multivariable model, patient characteristics associated with longer call-to-hospital time were age ≥75 years (2.3 min; 95% confidence interval [CI] 0.6-4.0), female sex (1.9 min; 95% CI 0.3-3.4), pre-existing mental health disorder (4.0 min; 95% CI 1.9-6.1) or musculoskeletal disease (2.7 min; 95% CI 1.0-4.4), absence of chest pain (3.0 min; 95% CI 1.1-4.8), and presentation with clinical complications. System factors associated with call-to-hospital time include lower dispatch priority (12.7 min; 95% CI 9.0-16.5) and non-12-lead electrocardiography (ECG) capable ambulance first on scene (4.5 min; 95% CI 3.1-5.8). Patients who were not initially attended by a 12-lead capable ambulance were less likely to receive a 12-lead ECG within 10 min (18.5% vs 71.0%, P < 0.001). A range of patient and system factors may influence EMS delays in STEMI. However, optimising dispatch prioritisation and widespread availability of prehospital 12-lead ECG could lead to substantial reduction in time to treatment.

A Statewide Assessment of Prehospital Electrocardiography Approaches of Acquisition and Interpretation for ST-Elevation Myocardial Infarction Based on Emergency Medical Services Characteristics

Background: The American Heart Association recommends acquiring and interpreting prehospital electrocardiograms (ECG) for patients transported by Emergency Medical Services (EMS) to the emergency department with symptoms highly suspicious of acute coronary syndrome. If interpreted correctly, prehospital ECGs have the potential to improve early detection of ST-elevation myocardial infarction (STEMI) and inform prehospital activation of the cardiac catheterization laboratory, thus reducing total ischemic time and improving patient outcomes. Standardized protocols for prehospital ECG interpretation methods are lacking due to variations in EMS system design, training, and procedures. Objectives: We aimed to describe approaches for prehospital ECG interpretation in EMS systems across North Carolina (NC), and examine potential differences among systems. Methods: A 35-item internet survey was sent to all NC EMS systems (n = 99). Questions pertaining to prehospital ECG interpretation methods included: paramedic, computerized algorithm (i.e., software interpretation), combined approaches, and/or transmission for physician interpretation, transmission capability, cardiac catheterization laboratory activation, and EMS system characteristics (e.g. rural versus urban). Data were summarized and compared. Results: A total of 96 EMS systems across NC responded to the survey (97% response rate); of these, 69% were rural. EMS medical directors (53%) or EMS administrative directors (42%) completed the majority of surveys. While 91% of EMS systems had a prehospital ECG interpretation protocol in place, only 61% had a written cardiac catheterization laboratory activation policy. More than half (55%) of systems reported paramedic interpretation of prehospital ECGs, followed by a combined paramedic and software interpretation approach (39%), physician interpretation (4%), or software interpretation only approach (2%). Nearly 80% of EMS systems transmitted prehospital ECGs to receiving hospitals (always or sometimes), regardless of interpretation method. All EMS systems had some paid versus non-paid EMS personnel and the majority (86%) had both basic and advanced life support capabilities. Conclusions: Most NC EMS systems had a paramedic only ECG interpretation or paramedic in combination with a computerized algorithm approach. Very few used a physician read approach following transmission, even in rural service areas.

Confidence Level and Knowledge of Pre-hospital Thrombolysis Therapy of Paramedic in Prehospital Care: A Survey

Data on knowledge, attitude and ST Elevation Myocardial Infarction (STEMI) electrocardiography (ECG) detection among pre-hospital paramedics in Malaysia is still scarce. It is imperative to gain this information as a pre-requisite in initiating pre-hospital thrombolysis. This was a descriptive study conducted from May 2016 until November 2017 on paramedics from Universiti Kebangsaan Malaysia Medical Center (UKMMC) and Kuala Lumpur Hospital (HKL). It was to assess knowledge on pre-hospital thrombolytic therapy and ECG detection of STEMI. One hundred and six questionnaires were answered and analyzed. More than 60% of the candidates were unable to detect STEMI ECG changes and lacked of confidence in handling and administering thrombolytic treatment at the level of pre-hospital phase. Only 20.8% candidates managed to detect more than 8/10 of the correct ECG pattern in STEMI. Less than 40% of the candidates achieved more than 80% marks in answering questions regarding STEMI and treatment. It is concluded that the overall performance and knowledge of paramedic regarding pre-hospital thrombolytic therapy is generally poor. Further training need to be done prior to implementing pre-hospital STEMI thrombolytic therapy in Malaysia.

Can WeChat group-based intervention reduce reperfusion time in patients with ST-segment myocardial infarction? A controlled before and after study

Background Pre-hospital identification of acute ST-elevation myocardial infarction and activation of the catheterization laboratory can reduce first medical contact to wire-crossing times. We conducted a study on providing 24-hour tele-electrocardiography services via the WeChat group application, aiming to reduce the time taken for diagnosis and treatment of ST-elevation myocardial infarction. Methods A controlled before and after study was conducted on 140 ST-elevation myocardial infarction patients who were initially seen in non-percutaneous coronary intervention-capable hospital and transferred for primary percutaneous coronary intervention at our percutaneous coronary intervention centre from 1 February to 31 October 2018. The WeChat group had 70 patients with pre-hospital electrocardiography transmission via WeChat and the control group had 70 patients who did not transfer pre-hospital electrocardiography. The reperfusion time of the two groups was compared to evaluate the effect of the WeChat group intervention. Results In the WeChat group versus the control group, the median symptom onset to first medical contact time was similar (129 vs 150 min, p > 0.05), but the median first medical contact to wire, door to wire and first medical contact to catheterization laboratory activity were significantly shorter (132 vs 171 minutes, p < 0.001; 60 vs 95 minutes, p < 0.001; 29 vs 74 minutes, p < 0.001, respectively). Conclusions Pre-hospital electrocardiography transfer via a WeChat group resulted in earlier reperfusion of ST-elevation myocardial infarction patients who were transferred from the non-percutaneous coronary intervention centre.

Characteristics of Prehospital Electrocardiogram Use in North Carolina Using a Novel Linkage of Emergency Medical Services and Emergency Department Data

Objective: Prehospital electrocardiography (ECG) is recommended for patients with suspected acute coronary syndrome (ACS), yet only 20–80% of chest pain patients receive a prehospital ECG. Less is known about prehospital ECG use in patients with less common complaints (e.g., fatigue) suspicious for ACS who are transported by emergency medical services (EMS). The aims of this study were to determine: (1) the proportion of patients with chest pain and less typical complaints, and (2) patient characteristics associated with prehospital ECG use in patients transported by EMS to emergency departments across North Carolina. Methods: A novel linked database was created between prehospital and emergency department (ED) patient care data from the North Carolina Prehospital Medical Information System and the North Carolina Disease Event Tracking and Epidemiologic Collection Tool. Institutional review board approval and a data use agreement were received prior to the start of the study. Patients ≥21 transported during 2010–14 by EMS with select variables were included. We examined patients’ complaints (symptoms), characteristics (e.g., race, ethnicity, final hospital diagnosis), and prehospital ECG use (yes/no). Analysis included descriptive statistics and mixed logistic regression. Results: During 2010–14, there were 1,967,542 patients with linked EMS-ED data (mean age: 56.9 [SD: 22.2], 43.2% male, 63.7% White). Of these, 643,174 (32.6%) received a prehospital ECG. Patients with prehospital ECG presented with the following complaints: 20% chest pain; 10% shortness of breath; 6% abdominal pain/problems; 6% altered level of consciousness; 5% syncope/dizziness; 4% palpitations; 12% other complaints; and 37% missing. Patients’ presenting complaints were the strongest predictor of prehospital ECG use, adjusting for age, sex, race, ethnicity, urbanicity, and date and time of EMS dispatch. Conclusions: Patients with chest pain were significantly more likely to receive a prehospital ECG compared to those with less typical but suspicious complaints for ACS. Patients with less common presentations remain disadvantaged for early triage, risk stratification, and intervention prior to the hospital.

Predictive ability and efficacy for shortening door-to-balloon time of a new prehospital electrocardiogram-transmission flow chart in patients with ST-elevation myocardial infarction – Results of the CASSIOPEIA study

BackgroundThe purposes of this study were to create a new flow-chart of prehospital electrocardiography (ECG)-transmission, evaluate its predictive ability for ST-elevation myocardial infarction (STEMI) and shorten door-to-balloon time (DTBT). Method and resultsThe new transmission flow-chart was created using symptoms from previous medical records of STEMI patients. A total of 4090 consecutive patients transferred emergently to our hospital were divided into two groups: those in ambulances with an ECG-transmission device with the new flow-chart (ECGT-FC) and those transferred without an ECG-transmission device (non-ECGT) groups. A STEMI group comprising walk-in patients during the same period was used as a control group. The predictive ability of STEMI and the effectiveness of shortening the DTBT by the new flow-chart of ECG-transmission was evaluated. In the ECGT-FC group, the prevalence of STEMI in the ECG-transmission by the new flow-chart were significantly higher than in the non-ECG-transmission patients (6.71% vs. 0.19%; p<0.001). The sensitivity and specificity of the new ECG-transmission flow-chart were 83.3% and 88.1%, respectively. The median DTBT was significantly shortened (p=0.045) and the prevalence of DTBT<90min was significantly higher in the ECGT-FC group (p=0.018) than the other groups. ConclusionThe sensitivity and specificity of the new flow-chart for ECG-transmission were high. The new flow-chart combined with an ECG-transmission device could detect STEMI efficiently and shorten DTBT.

Effectiveness of a Prehospital Wireless 12-Lead Electrocardiogram and Cardiac Catheterization Laboratory Activation for ST-Elevation Myocardial Infarction

The aim of the study was to determine the prevalence of false-positive and inappropriate cardiac catheterization laboratory (CCL) activation in patients suspected with ST-elevation myocardial infarction (STEMI) diverted to a percutaneous coronary intervention (PCI) facility after paramedics wireless 12-lead electrocardiogram transmission to an emergency physician at an online medical control center. This retrospective study collected data from medical records of patients with suspected STEMI from 2006 to 2014. It included demographics, coronaropathic risk factors, cardiac biomarkers, time from the first medical contact to treatment, and final diagnosis. Primary outcome was the rate of false-positive and inappropriate CCL activation. As secondary outcomes, we compared patient characteristics between cases of appropriate and inappropriate CCL activation, and we assessed the presence of cardiac biomarkers, time from first medical contact to start of PCI, and final diagnosis. Overall, 673 patients with suspected STEMI were included in the analysis. A total of 640 patients (95%) had coronarography, of which 10% (62 of 640) did not have a culprit coronary artery (false positive). Angiography was canceled for 5% (33 of 673) of patients. The total false-positive and inappropriate CCL activation rate was 14% (95 of 673). Average time from the first medical contact to the start of PCI was 47 ± 18.1minutes. Unwanted CCL activations were more likely to involve men aged >65years and patients with a history of coronary artery disease. In conclusion, our system of transmitted prehospital electrocardiography and STEMI interpretation by emergency physicians at an online medical control center showed a total false-positive and inappropriate CCL activation rate of 14% over the 8-year study period.

Normal prehospital electrocardiography is linked to long-term survival in patients presenting to the emergency department with symptoms of acute coronary syndrome

Aims/methodsWe studied 735 patients who activated "911" for chest pain and/or anginal equivalent symptoms and received 12-lead ECG monitoring with specialized ischemia monitoring software in the ambulance. Prehospital electrocardiograms (PH ECG) were analyzed to determine the proportion of patients who present with completely normal PH ECG findings (absence of ischemia/infarction, arrhythmia, or any other abnormality) and to compare outcomes among patients with and without any PH ECG abnormality. ResultsOf 735 patients (mean age 70.5, 52.4% male), 68 (9.3%) patients had completely normal PH ECG findings. They experienced significantly less adverse hospital outcomes (12% vs 37%), length of stay (1.19 vs 3.86days), and long-term mortality (9% vs 28%) than those with any PH ECG abnormality (p<.05). ConclusionNormal PH ECG findings are associated with better short and long-term outcomes in ambulance patients with ischemic symptoms. These findings may enhance early triage and risk stratification in emergency cardiac care.

Normal prehospital electrocardiography is linked to long-term survival in patients presenting to the emergency department with symptoms of acute coronary syndrome

Normal prehospital electrocardiography is linked to long-term survival in patients presenting to the emergency department with symptoms of acute coronary syndrome

Prehospital Computer Interpretation of ECGs Is Inaccurate

Prehospital electrocardiography is frequently used to reduce door-to-balloon times for patients with suspected ST-segment elevation myocardial

Pre-Hospital Electrocardiography by Emergency Medical Personnel: Effects on Scene and Transport Times for Chest Pain and ST-Segment Elevation Myocardial Infarction Patients

This study sought to measure the impact of pre-hospital (PH) electrocardiography (ECG) on scene-to-hospital time for patients with chest pain of cardiac origin and those with ST-segment elevation myocardial infarction (STEMI).Pre-hospital ECG decreases door-to balloon (D2B) time for STEMI patients. However, obtaining a PH ECG might prolong scene time. We investigated the impact of obtaining a PH ECG on both scene and transport times for patients with chest pain suspected of cardiac origin.City of San Diego Emergency Medical System runsheets of patients with chest pain from January 2003 to April 2008 were analyzed. The scene times and transport times were compared before (from January 2003 to December 2005) and after (from January 2006 to April 2008) implementation of the PH ECG. Among patients with a PH ECG, median scene times and transport times were compared in patients with and without STEMI.There were 21,742 patients evaluated for chest pain during the study period. Implementation of PH ECG resulted in minimal increases in median scene time (19 min, 10 s vs. 19 min, 28 s, p = 0.002) and transport time (13 min, 16 s vs. 13 min, 28 s, p = 0.007). However, compared with chest pain patients, in STEMI patients (n = 303), shorter median scene time (17 min, 51 s vs. 19 min, 31 s, p < 0.001), transport time (12 min, 34 s vs. 13 min, 31 s, p = 0.006), and scene-to-hospital time was observed (30 min, 45 s vs. 33 min, 29 s, p < 0.001).Obtaining a PH ECG for patients with chest pain minimally prolongs scene and transport times. Further, for STEMI patients, both scene times and transport times are actually reduced leading to a potential reduction in total ischemic time.

Retrospective Description and Analysis of Consecutive Catheterization Laboratory ST-Segment Elevation Myocardial Infarction Activations With Proposal, Rationale, and Use of a New Classification Scheme

Rapid activation of a cardiac catheterization laboratory (CCL) has reduced door-to-balloon times in ST-segment elevation myocardial infarction (STEMI), leading to lower mortality. This process is accelerated with prehospital electrocardiography and notification. False activations of the CCL occur at an unknown rate and have been poorly described. We analyzed 345 consecutive CCL activations for suspected STEMI over 18 months (March 2009-August 2010). We retrospectively reviewed the ECGs that prompted activation, as well as the clinical course and final diagnoses. Among all CCL activations, STEMI was not confirmed in 28%. On review, 301 (87.2%) had appropriate ECG criteria for activation. However, even among the ECG-appropriate patients, only 247 (82%) had a final diagnosis of STEMI. The inclusion of clinical characteristics did not improve the ability to identify patients with STEMI. Activations were modestly more accurate when made by emergency department physicians than by emergency medical service personnel, but door-to-balloon time was noticeably shorter when emergency medical service personnel requested prehospital activation. If all CCL activations are considered, the occurrence of false activations is surprisingly high. Although still the gold standard for diagnosis, these data reveal the inherent limitations of clinical evaluation and the ECG in identifying patients with STEMI. Within our retrospective review, we used a 2-tiered classification for STEMI activations based on ECG appropriateness and final clinical diagnosis to give a complete picture of false activations and assist in quality improvement.

Prehospital Electrocardiography: A Review of the Literature

The American Heart Association and other scientific guidelines recommend emergency medical services acquire prehospital (PH) electrocardiography (ECG) in all patients with symptoms of acute coronary syndrome. The purpose of this article is to critically review the scientific literature about PH ECG. Using multiple search terms, we searched the PubMed and Web of Science databases for relevant information. Search limiters were used: human, research (clinical trials, experimental), core journals, and adult. All articles about the clinical effects of PH ECG published between 2001 and 2011 were retained, in addition to a landmark study from 1997. Our search yielded a total of 105 articles when all years of publication were considered. When the same search was limited to articles published between 2001 and 2011 for new and current data, 45 articles were returned. A total of 7 articles about the clinical effects of PH ECG were retained for this review. Articles were conceptualized and organized by clinical effects of PH ECG (timing, reperfusion rate, death, ejection fraction, reinfarction, and stroke). PH ECG has been associated with reduced PH delay time, increased use of reperfusion interventions, earlier diagnosis, and faster time to treatment. PH ECG plays a major role in emergency cardiac systems of care and can facilitate early intervention by identifying patients with acute coronary syndrome sooner.

Prehospital ECGs for Acute Coronary Syndromes

Prehospital electrocardiography has the potential to improve care of patients with ST-segment-elevation myocardial infarction (STEMI) by shortening time to reperfusion therapy. Current American Heart Association (AHA) guidelines recommend that paramedics routinely perform and evaluate prehospital electrocardiograms for patients with chest pain and suspected STEMI. However, prehospital ECGs currently are obtained in …

Prehospital 12-Lead ECG: Efficacy or Effectiveness?

Introduction. Previous literature has documented that prehospital 12-lead electrocardiography (ECG) decreases the time to reperfusion in patients with an acute ST-segment elevation myocardial infarction (STEMI). Objective. To compare time to ECG, time to angioplasty suite (laboratory), andtime to reperfusion in emergency medical services (EMS) STEMI patients, who received care through three different processes. Methods. The setting was a large suburban community teaching hospital with emergency department (ED)-initiated single-page acute myocardial infarction (AMI) team activation for STEMI patients. The population was STEMI patients transported by EMS from January 2003 to October 2005. Not all EMS agencies had prehospital 12-lead ECG capability. Paramedics interpret andverbally report clinical assessment andECG findings via radio. The AMI team is activated at the discretion of the emergency physician 1) before patient arrival to the ED based on EMS assessment, 2) after ED evaluation with EMS ECG, or 3) after ED evaluation andED ECG. Time intervals were calculated from ED arrival. To assess the impact of interventions on performance targets, we also report the proportion of patients who arrived in laboratory within 60 minutes andreperfusion within 90 minutes of arrival. Parametric andnonparametric statistics are used for analysis. Results. During the study period, there were 164 STEMI patients transported by EMS; mean age was 66.1 years, and56% were male. Of these, 93 (56.7%) had an EMS ECG and31 (33%) had AMI team activation before ED arrival. Mean time to laboratory for all patients was 49.8 ± 34.4 minutes andtime to reperfusion was 93.2 +/− 34.5 min. Patients with prearrival activation were transported to laboratory sooner (mean, 24.3 vs. 53. 4 minutes; p < 0.001) andreceived reperfusion sooner than all other patients (mean, 70.4 vs. 96.3 minutes; p = 0.007). More prearrival activation patients met performance targets to laboratory (96.7% vs. 73.7%; p = 0.009) andreperfusion (85.2% vs. 51.0%; p = 0.003). There was no difference in time to laboratory or to reperfusion for patients who received EMS ECG but no prearrival activation compared with those who received EMS transport alone. Conclusions. A minority of patients with EMS ECGs had prearrival AMI team activation. EMS ECGs combined with systems that activate hospital resources, but not EMS ECGs alone, decrease time to laboratory andreperfusion.