Prehospital 12-lead Electrocardiogram Research Articles

Ability of First-Year Paramedic Students to Identify ST-Segment Elevation Myocardial Injury on 12-Lead Electrocardiogram: A Pilot Study

The purpose of this study was to evaluate the ability of firstyear paramedic students to identify ST-segment elevation myocardial injury (STEMI) on 12-lead electrocardiograms (ECGs) following a three-hour presentation by a board-certified emergency medicine physician experienced in ECG interpretation. Thirty-three first-year paramedic students with minimal to no experience in evaluating 12-lead ECGs were administered a pre-test with 20 12-lead ECGs and were asked to evaluate each for: (1) presence of STEMI (STEMI identification); (2) if STEMI presents, ECG leads demonstrating ST-elevation (LEAD identification); and (3) if STEMI present, the anatomic distribution of the STEMI (ANATOMY identification). The students were randomized into two groups. Group 1 (16 students; control group) received a handout describing the evaluation of ECGs for STEMI, while Group 2 (17 students; experimental group) received the handout plus a three hour presentation on the evaluation of ECGs for STEMI. Following randomization, distribution of the STEMI handout and ECG STEMI presentation, a post-test with 20 new ECGs was administered to all participants. The pretest and post-test mean scores were compared between the two groups to determine if attendance at the presentation improved the paramedic students' abilities to evaluate and identify STEMI ECGs. Following the STEMI posttest, students in Group 1 were provided with the STEMI lecture. Students were retested with 20 new ECGs five months following the initial study to examine retention of the information taught. The mean pre-test scores for the two groups (Group 1 vs Group 2, respectively) in STEMI identification (74.4 vs 75.6%; p=0.79), lead identification (50.0 vs. 51.2%; p=0.8) and anatomy identification (49.4 vs 51.8%; p=0.60) were similar in all three categories. Post-test scores between Group 1 and Group 2 demonstrated statistically significant differences in STEMI identification (85.6 vs 92.4%; p<0.02), lead identification (73.4 vs 85.2%; p<0.02), and anatomy identification (65.9 vs 87.1%; p<0.01), with Group 2 demonstrating higher mean scores relative to Group 1 in all three categories. Comparison of mean initial pre-test and five-month retest scores for all students demonstrated statistically significant differences in STEMI identification (75.0 vs 87.4%; p<0.0001), lead identification (50.6 vs 82.2%; p<0.0001), and anatomy identification (50.6 vs 76.6%; p<0.0001). The ability of first-year paramedic students to accurately detect STEMI on prehospital 12-lead ECGs is enhanced by a structured ECG STEMI presentation provided by an emergency medicine physician, and these students maintained excellent retention of STEMI ECG skills over a five-month period.

Early Cardiac Catheterization Laboratory Activation by Paramedics for Patients with ST-segment Elevation Myocardial Infarction on Prehospital 12-Lead Electrocardiograms

Background. Prompt reperfusion in ST-segment elevation myocardial infarction (STEMI) saves lives. Although studies have shown that paramedics can reliably interpret STEMI on prehospital 12-lead electrocardiograms (p12ECGs), prehospital activation of the cardiac catheterization laboratory by emergency medical services (EMS) has not yet gained widespread acceptance. Objective. To quantify the potential reduction in time to percutaneous coronary intervention (PCI) by early prehospital activation of the cardiac catheterization laboratory in STEMI. Methods. This prospective, observational study enrolled all patients diagnosed with STEMI by paramedics in a mid-sized regional EMS system. Patients were enrolled if: 1) the paramedic interpreted STEMI on the p12ECG, 2) the Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI) score was 75%% or greater, and 3) the patient was transported to either of two area PCI centers. Data recorded included the time of initial EMS “STEMI alert” from the scene, time of arrival at the emergency department (ED), and time of actual catheterization laboratory activation by the ED physician, all using synchronized clocks. The primary outcome measure was the time difference between the STEMI alert and the actual activation (i.e., potential time savings). The false-positive rate (patients incorrectly diagnosed with STEMI by paramedics) was also calculated and compared with a locally accepted false-positive rate of 10%%. Results. Twelve patients were enrolled prior to early termination of the study. The mean and median potential time reductions were 15 and 11 minutes, respectively (range 7–29 minutes). There was one false STEMI alert (8.3%% false-positive rate) for a patient with a right bundle branch block who subsequently had a non–ST-segment elevation myocardial infarction. The study was terminated when our cardiologists adopted a prehospital catheterization laboratory activation protocol based on our initial data. Conclusion. Important reductions in time to reperfusion seem possible by activation of the catheterization laboratory by EMS from the scene, with an acceptably low false-positive rate in this small sample. This type of clinical research can inform multidisciplinary policies and bring about meaningful clinical practice changes.

Underuse of prehospital strategies to reduce time to reperfusion for ST-elevation myocardial infarction patients in 5 Canadian provinces

Timely reperfusion therapy for ST-elevation myocardial infarction (STEMI) is an important determinant of outcome, yet targets for time to treatment are frequently unmet in North America. Prehospital strategies can reduce time to reperfusion. We sought to determine the extent to which emergency medical services (EMS) use these strategies in Canada. We carried out a cross-sectional survey in 2007 of ground EMS operators in British Columbia, Alberta, Ontario, Quebec and Nova Scotia. We focused on the use of 4 prehospital strategies: 1) 12-lead electrocardiogram (ECG), 2) routine expedited emergency department (ED) transfer of STEMI patients (from a referring ED to a percutaneous coronary intervention [PCI] centre), 3) prehospital bypass (ambulance bypass of local EDs to transport patients directly to PCI centres) and 4) prehospital fibrinolysis. Ninety-seven ambulance operators were surveyed, representing 15 681 paramedics serving 97% of the combined provincial populations. Of the operators surveyed, 68% (95% confidence interval [CI] 59%-77%) had ambulances equipped with 12-lead ECGs, ranging from 40% in Quebec to 100% in Alberta and Nova Scotia. Overall, 47% (95% CI 46%-48%) of paramedics were trained in ECG acquisition and 40% (95% CI 39%-41%) were trained in ECG interpretation. Only 18% (95% CI 10%-25%) of operators had prehospital bypass protocols; 45% (95% CI 35%-55%) had protocols for expedited ED transfer. Prehospital fibrinolysis was available only in Alberta. All EMS operators in British Columbia, Alberta and Nova Scotia used at least 1 of the 4 prehospital strategies, and one-third of operators in Ontario and Quebec used 0 of 4. In major urban centres, at least 1 of the 3 prehospital strategies 12-lead ECG acquisition, bypass or expedited transfer was used, but there was considerable variation within and across provinces. The implementation of widely recommended prehospital STEMI strategies varies substantially across the 5 provinces studied, and relatively simple existing technologies, such as prehospital ECGs, are underused in many regions. Substantial improvements in prehospital services and better integration with hospital-based care will be necessary in many regions of Canada if optimal times to reperfusion, and associated outcomes, are to be achieved.

Overcoming barriers to developing seamless ST-segment elevation myocardial infarction care systems in the United States: recommendations from a comprehensive Prehospital 12-lead Electrocardiogram Working Group

Background Reducing time to reperfusion treatment for patients with ST-segment elevation myocardial infarction (STEMI) improves patient outcomes. Few medical systems consistently meet current benchmarks regarding timely access to treatment. Studies have widely demonstrated that prehospital 12-lead electrocardiography can facilitate early catheterization laboratory activation and is the most effective means of decreasing patients' time to treatment. Methods We gathered experts to examine the barriers to implementation of prehospital 12-lead electrocardiographic monitoring and transmission to in-hospital cardiologists in creating seamless STEMI care systems (STEMI-CS) and propose multidisciplinary approaches to overcoming these barriers. Results and Conclusions Physicians, hospital systems, and emergency medical services often lack coordination of care delivery and receive fragmented funding and oversight. Clinical and regulatory guidelines do not emphasize local solutions to achieving clinical benchmarks, do not target incentives at all components of the STEMI-CS, and underemphasize risk-based approaches to protecting patient health. Integration of the multiple complex components involved in STEMI-CS is essential to improving care delivery.

Implementation of Specialty Centers for Patients with ST-Segment Elevation Myocardial Infarction

Background. Early percutaneous coronary intervention (PCI) has been shown to be superior to fibrinolytic therapy andis associated with reduced morbidity andmortality for patients with ST-segment elevation myocardial infarction (STEMI). Objective. To determine the performance of a regional system with prehospital 12-lead electrocardiogram (ECG) identification of STEMI patients anddirect paramedic transport to STEMI receiving centers (SRCs) for provision of primary PCI. Methods. This was a prospective study evaluating the first year of implementation of a regional SRC network to determine the key time intervals for patients identified with STEMI in the prehospital setting. Results. During the 12-month study period, 1,220 patients with a suspected STEMI were identified on prehospital 12-lead ECG, of whom 734 (60%) underwent emergency PCI. A door-to-balloon time of 90 minutes or less was achieved for 651 (89%) patients, and459 (62.5%) had EMS–patient contact-to-balloon times ≤ 90 minutes. Transport of suspected STEMI patients to an SRC resulted in ambulance diversion from a closer ED for 31% of patients anda median increase in transport time of 3.8 minutes. Conclusion. Door-to-balloon times within the 90-minute benchmark were achieved for almost 90% of STEMI patients transported by paramedics after implementing our regionalized SRC system

Impact of Paramedic Transport with Prehospital 12-Lead Electrocardiography on Door-to-Balloon Times for Patients with ST-Segment Elevation Myocardial Infarction

Objective. To determine the impact of prehospital 12-lead electrocardiograms (ECGs) on door-to-balloon times for ST-segment elevation myocardial infarction (STEMI) patients prior to the establishment of formally designated STEMI receiving centers. Methods. This was a retrospective study comparing door-to-balloon times for acute STEMI patients transported by paramedics using prehospital 12-lead ECGs with those who arrived via self-transport at four Los Angeles area EDs that performed emergency percutaneous coronary intervention (PCI). Paramedics calling in from the field verbally notified receiving hospitals of a “STEMI patient.” Activation of the hospital's PCI team was at the discretion of the receiving emergency physician. During the study period, there were no formal diversion criteria for STEMI patients. The main outcome measure was door-to-balloon time. Results. During the study period, 234 patients met inclusion criteria, of whom 168 (72%) were male. The mean age was 62 years. There was no statistically significant difference in the age, gender, or ethnicity of the two groups. Median door-to-balloon times were 95 minutes and108 minutes in the EMS andself-transport groups, respectively (p < 0.05; 95% confidence interval 3.5–16.4). Conclusion. Paramedic transport of STEMI patients with prehospital 12-lead ECG acquisition was associated with shorter door-to-balloon times than the times for patients who self-transported to PCI-capable EDs

Can Paramedics Read ST-segment Elevation Myocardial Infarction on Prehospital 12-Lead Electrocardiograms?

Introduction. Activation of the cardiac catheterization laboratory prior to patient arrival at the hospital, based on a prehospital 12-lead electrocardiogram (ECG), reduces door-to-balloon time by 10–55 minutes for patients with ST-segment elevation myocardial infarction (STEMI). In emergency medical services (EMS) systems where transmission of the ECG to the emergency department (ED) is not feasible, the ability of paramedics to accurately read 12-lead ECGs is crucial to the success of a prehospital catheterization laboratory activation program. Objective. To determine whether paramedics can accurately diagnose STEMI on a prehospital 12-lead ECG anddecide to activate the cardiac catheterization laboratory appropriately. Methods. Five chest pain scenarios were generated, with standardized prehospital ECGs accompanying each: three STEMI cases that should result in catheterization laboratory activation andtwo non-STEMI cases that should not. A convenience sample of paramedics in an urban/suburban EMS system examined each scenario andECG, andindicated whether the patient had STEMI andwhether they would activate the catheterization laboratory. A series of demographic andoperational questions were also asked of each participant. We report diagnostic statistics, agreement (kappa), and95% confidence intervals (CIs). Results. A convenience sample of 103 of 147 eligible paramedics (70%) was enrolled. For STEMI diagnosis, paramedics' sensitivity was 92.6% (95% CI 88.9–95.1) andspecificity was 85.4% (79.7–89.8); for catheterization laboratory activation, sensitivity was 88.0% (83.8–91.3) andspecificity was 88.3% (83.0–92.2). False-positive activation of the catheterization laboratory occurred in 8.1% (5.4–12.0) of cases. Of the STEMI cases, 94.1% were correctly read as STEMI, and91.0% had the catheterization laboratory appropriately activated. Of the non-STEMI cases, 14.9% were incorrectly read as STEMI, and12.0% had the catheterization laboratory inappropriately activated. The paramedics' comfort with calling a “chest pain alert” with no resulting catheterization laboratory activation (the current practice in this system) was not statistically different from their comfort with calling a chest pain alert if that call were to automatically result in catheterization laboratory activation (p > 0.05). Conclusions. Paramedics in an urban/suburban EMS system can diagnose STEMI andidentify appropriate cardiac catheterization laboratory activations with a high degree of accuracy, andan acceptable false-positive rate, when tested using paper-based scenarios.

Effect on Treatment Delay of Prehospital Teletransmission of 12-Lead Electrocardiogram to a Cardiologist for Immediate Triage and Direct Referral of Patients With ST-Segment Elevation Acute Myocardial Infarction to Primary Percutaneous Coronary Intervention

Prehospital electrocardiogram (ECG) transmission to hospitals was shown to reduce time to treatment in patients with acute myocardial infarction. However, new technologies allow transmission directly to a mobile unit so an attending physician can respond irrespective of presence within or outside the hospital. The primary study purpose was to determine whether delays could be decreased in an urban area by transmitting a prehospital 12-lead ECG directly to the attending cardiologist's mobile telephone for rapid triage and transport to a primary percutaneous coronary intervention (PCI) center, bypassing local hospitals and emergency departments. A secondary purpose was to describe whether transport would be safe despite longer transport times. During a 2-year period, patients with acute nontraumatic chest pain had their prehospital ECG transmitted directly to a cardiologist's mobile telephone. Time to treatment was compared with historic controls. After ECG evaluation, 168 patients (30%) were referred directly for PCI, and 146 of these (87%) underwent emergent catheterization. In referred patients, median time from 911 call to PCI was significantly shorter than in the control group (74 vs 127 minutes; p <0.001). Accordingly, door-to-PCI time was 63 minutes shorter for referred patients versus controls (34 vs 97 minutes; p <0.001). During transport, 7 patients (4%) experienced ventricular fibrillation; 3 patients (2%), ventricular tachycardia; and 1 patient (0.5%), pulseless electrical activity, including 2 deaths (1%) caused by treatment-resistant arrhythmia. In conclusion, transmission of a prehospital 12-lead ECG directly to the attending cardiologist's mobile telephone decreased door-to-PCI time by >1 hour when patients were transported directly to PCI centers, bypassing local hospitals. Ambulance transport seems safe despite longer transport times.

Referral of patients with ST-segment elevation acute myocardial infarction directly to the catheterization suite based on prehospital teletransmission of 12-lead electrocardiogram

Background Time from symptom onset to reperfusion is essential in patients with ST-segment elevation acute myocardial infarction. Prior studies have indicated that prehospital 12-lead electrocardiogram (ECG) transmission can reduce time to reperfusion. Purpose Determine 12-lead ECG transmission success rates, and time saved by referring patients directly to primary percutaneous coronary intervention (pPCI) bypassing local hospitals and emergency departments. Methods Prehospital 12-lead ECG was recorded in patients with symptoms suggesting acute coronary syndrome during a 1-year pilot phase and transmitted to the attending cardiologist's mobile phone. Transmission success rates were determined, and prehospital and hospital delays were recorded and compared to historic controls. Results Transmission was attempted in 152 patients and was successful in 89%. Twenty-seven patients were referred directly for pPCI. Median hospital arrival to pPCI was 22 vs 94 minutes in the control group ( P < .01). Conclusions Transmission of prehospital ECG is technically feasible and reduces time to pPCI in ST-segment elevation acute myocardial infarction patients.

Effect of Prehospital 12-Lead Electrocardiogram on Activation of the Cardiac Catheterization Laboratory and Door-to-Balloon Time in ST-Segment Elevation Acute Myocardial Infarction

Reducing door-to-balloon (D + B) time during primary percutaneous coronary intervention for patients with ST-segment elevation myocardial infarction (STEMI) reduces mortality. Prehospital 12-lead electrocadiography (ECG) with cardiac catheterization laboratory (CCL) activation may reduce D + B time. Paramedic-performed ECG was initiated in the city of San Diego in January 2005 with STEMI diagnosis based on an automated computer algorithm. We undertook this study to determine the effect of prehospital CCL activation on D + B time for patients with acute STEMI brought to our institution. All data were prospectively collected for patients with STEMI including times to treatment and clinical outcomes. We evaluated 78 consecutive patients with STEMI from January 2005 to June 2006, and the study group consisted of all patients with prehospital activation of the CCL (field STEMI; n = 20). The control groups included concurrently-treated patients with STEMI during the same period who presented to the emergency department (nonfield STEMI; n = 28), and all patients with STEMI treated in the preceding year (2004) (historical STEMI; n = 30). Prehospital CCL activation significantly reduced D + B time (73 +/- 19 minutes field STEMI, 130 +/- 66 minutes nonfield STEMI, 141 +/- 49 minutes historical STEMI; p <0.001) with significant reductions in door-to-CCL and CCL-to-balloon times as well. The majority of patients with field STEMI achieved D + B times of <90 minutes (80% field STEMI, 25% nonfield STEMI, 10% historical STEMI; p <0.001). In conclusion, this study demonstrates that prehospital electrocardiographic diagnosis of STEMI with activation of the CCL markedly reduces D + B time.

The Positive Predictive Value of Paramedic Versus Emergency Physician Interpretation of the Prehospital 12-Lead Electrocardiogram

Background. Obtaining a prehospital 12-lead ECG may improve triage andexpedite care of patients with acute myocardial infarction (AMI). Whether the ECG should undergo physician review prior to activation of a percutaneous intervention (PCI) team is unclear. Objective. To document the positive predictive value (PPV) of the prehospital 12-lead ECG when interpreted by paramedics versus emergency physicians. Methods. This was a prospective, observational study. In November 2003, our local health care andemergency medical services (EMS) systems implemented a prehospital “cardiac alert” program in which patients suspected of having ST-elevation myocardial infarction (STEMI) based on the prehospital 12-lead ECG were diverted away from receiving facilities without emergent PCI capability andthe PCI team was mobilized. For the first year, a cardiac alert was activated by paramedics (Phase I). After the first year, the ECG was transmitted to the ED, with the emergency physician (EP) responsible for activation (Phase II). The PPV for cardiac alerts in Phases I andII were compared by using three different “gold standards”: cardiologist interpretation of the prehospital 12-lead ECG, disposition to emergent PCI, andcoronary lesions on angiography or arrest prior to emergent PCI. Results. A total of 110 patients were enrolled (54 in Phase I, 56 in Phase II). Cardiologist confirmation of a STEMI on the prehospital 12-lead EKG was 42/54 (78%) in Phase I and54/56 (96%) in Phase II. Disposition to emergent PCI occurred in 38/54 (70%) Phase I patients and51/56 (91%) Phase II patients. Lesions at catheterization or arrest prior to emergent PCI were observed in 41/54 (69%) of Phase I patients and50/56 (89%) of Phase II patients. All of these comparisons achieved statistical significance (p < 0.01). Conclusions. Transmission to the ED for EP interpretation improves the PPV of the prehospital 12-lead ECG for triage andtherapeutic decision-making.

Novel electrocardiogram configurations and transmission procedures in the prehospital setting: effect on ischemia and arrhythmia determination

Aim The aims of this report are to (1) describe a novel prehospital 12-lead electrocardiogram (ECG) configuration and transmission procedure used in the Synthesized Twelve-lead ST Monitoring and Real-time Tele-electrocardiography Study and to (2) report on the frequency of arrhythmias in field ECGs compared with the first hospital ECG. Methods The Synthesized Twelve-lead ST Monitoring and Real-time Tele-electrocardiography Study is a 5-year randomized clinical trial ending in 2008. All emergency vehicles responding to 911 calls in Santa Cruz County, Calif, have been equipped with portable monitor defibrillators with a special study software that (1) synthesizes a 12-lead ECG from 5 electrodes, (2) measures ST amplitudes in all 12 leads every 30 seconds, and (3) automatically transmits an ECG to the target emergency department if there is a change in ST amplitude of 200 μV in 1 lead or more or 100 μV in 2 contiguous leads or more lasting 2.5 minutes. An initial ECG is transmitted by paramedics, which activates the software. Subsequent transmissions of ST event ECGs occur automatically without paramedic decision making. Results Prehospital ECGs had a greater frequency of arrhythmias than the first hospital ECG in the group as a whole (n = 433; 33.3% vs 28.9%; P ≤ .001), as well as the subgroup with acute coronary syndrome (n = 185; 30.3% vs 26.5%; P ≤ .001). More tachyarrhythmias occurred in the field and slightly more bradyarrhythmias occurred at the time of the first hospital ECG. Conclusions Prehospital continuous 12-lead ST-segment ischemia monitoring with computer-assisted automatic mobile telephone transmission of ST event ECGs to the target hospital is feasible. More arrhythmias occur in the prehospital phase than are evident on the first hospital ECG.

Prehospital 12‐lead Electrocardiography Impact on Acute Myocardial Infarction Treatment Times and Mortality: A Systematic Review

Prehospital 12-lead electrocardiogram (PHECG) interpretation and advance emergency department (ED) notification may improve time-to-treatment intervals for a variety of treatment strategies to improve outcome in acute myocardial infarction. Despite consensus guidelines recommending this intervention, few emergency medical services (EMS) employ this. The authors systematically reviewed the literature to report whether mortality or treatment time intervals improved when compared with standard care. The authors used the Cochrane strategy to search MEDLINE, EMBASE, Current Contents, Dissertation Abstracts, Cochrane Library, and Index of Scientific and Technical Proceedings. Bibliographies and grant-agency Websites were reviewed, and primary investigators and industry were contacted for published and unpublished studies. Inclusion criteria included PHECG and advance ED notification versus standard EMS care; controlled trials; English only; and evaluation of treatment time intervals, all-cause mortality, or both. Study selection was hierarchical, blinded, and independent. Agreement at each level of review was evaluated by using a kappa statistic. Study quality was measured with a validated scale and was interpreted by two independent reviewers. A total of 1,283 citations were identified, and five studies met the inclusion criteria. The weighted kappa for selection was 0.61 (standard error [SE], 0.045) for titles, 0.63 (SE, 0.051) for abstracts, and 0.79 (SE, 0.146) for full articles. Mean study quality measures by two independent reviewers were 6.0/15 and 5.5/15 (correlation coefficient, 0.85; p = 0.06). PHECG and advance ED notification increased the weighted mean on-scene time by 1.2 minutes (95% confidence interval [95% CI] = -0.84 to 3.2). The weighted mean door-to-needle interval was shortened by 36.1 minutes (95% CI = 9.3 to 63.0: range of means, 22-48 minutes vs. 50-97 minutes). One study reported all-cause mortality, with a statistically nonsignificant reduction from 15.6% to 8.4%. For patients with AMI, the literature would suggest that PHECG and advanced ED notification reduces in hospital time to fibrinolysis. One controlled trial found no difference in mortality with this out-of-hospital intervention.

Comparison of EASI-derived 12-lead electrocardiograms versus paramedic-acquired 12-lead electrocardiograms using Mason-Likar limb lead configuration in patients with chest pain

Introduction Monitoring or serial 12-lead electrocardiogram (ECG) recordings are the accepted requirement for prehospital data acquisition in patients with chest pain. The purpose of this study was to determine whether waveforms and clinical triage decision are similar in EASI-derived ECGs and paramedic-acquired 12-lead ECGs using Mason-Likar limb lead configuration when compared with standard 12-lead ECGs (stdECG). Method Twenty patients with chest pain had a prehospital 12-lead ECG recorded in the ambulance, and paramedic-applied electrodes retained in place at hospital arrival. An ECG technician applied standard precordial and EASI electrodes in their correct positions. Twelve-lead ECGs were obtained from the paramedic-applied electrodes, using their Mason-Likar limb lead configuration, and derived from the EASI leads for comparison with the stdECG. Three computer-measured QRS-T waveform parameters were considered, and differences in waveform measurement between EASI and stdECG (EASI ΔstdECG) versus differences in waveform measurements between paramedic Mason-Likar and stdECG (PML ΔstdECG) were calculated. Two physicians determined whether the EASI-derived or the paramedic Mason-Likar ECG contained information that would change their clinical triage decision from that indicated by the stdECG. Results EASI ΔstdECG and PML ΔstdECG were identical in 28%, whereas EASI ΔstdECG was more than PML ΔstdECG in 35%, and PML ΔstdECG was accurate (both time) than EASI ΔstdECG in 37% ( P = .62). The physicians were more likely to change the level of patient care based on the EASI-derived ECGs compared with the paramedic ECGs; however, this difference was not statistically significant ( P = .27), but this may only be caused by the small study population. Conclusions There are similar differences from stdECG waveforms in EASI-derived ECGs and those acquired via paramedic-applied precordial electrodes using Mason-Likar limb lead configuration. Either method can be used as a substitute for monitoring, but neither should be considered equivalent to the stdECG for diagnostic purposes.

Diversion of ST-elevation myocardial infarction patients for primary angioplasty based on wireless prehospital 12-lead electrocardiographic transmission directly to the cardiologist's handheld computer: a progress report

Background Time to reperfusion is critical for outcome in patients with ST-elevation myocardial infarction (STEMI). In our region, patients are routinely treated by primary percutaneous coronary intervention (pPCI), but rerouting patients from the primary receiving hospital to a catheterization center can cause unacceptable delays that may exceed 1 hour in the emergency department. Wireless transmission of prehospital electrocardiograms (ECGs) to receiving stations in hospitals has been shown to reduce time from symptom onset to reperfusion. However, transmission directly to a cardiologist's handheld digital device has not been investigated. Aim To report preliminary data from a larger ongoing trial evaluating prehospital 12-lead ECG transmission to a cardiologist's handheld device in patients with symptoms suggesting an acute coronary syndrome. Method Patients suffering acute, nontraumatic chest pain have their prehospital ECG transmitted by wireless technology directly to a cardiologist's handheld device at an invasive hospital, allowing diversion of STEMI cases to rapid pPCI. Transmission failures are documented. Times for symptom onset, 911 alert, ECG recording, hospital arrival, and pPCI are obtained. All time intervals are summarized as median values and are compared with historic controls from the Danish multicenter study, DANAMI-2. Results During the first 15 months of the trial, prehospital ECGs were transmitted for 408 chest pain patients with an overall success rate of 93%. Cardiologist receiving the ECGs recommended that 113 patients (28%) be diverted for pPCI. Mean time from symptom onset to 911 alert was 2 hours 16 minutes (range, 1 minute to 23 hours 15 minutes), and the ambulance response interval was 5 minutes (range, 1-25 minutes). The ambulance on-scene time had increased by 7 minutes compared with historic controls ( P < .05). Time from ECG recording to hospital arrival was 25 minutes. The total prehospital time was 2 hours 57 minutes. The hospital treatment time was substantially reduced among diverted patients. Hospital arrival to procedure start was 40 minutes, compared with 94 minutes in the DANAMI-2 historic control group ( P < .01). Conclusion These preliminary data suggest that transmission of prehospital 12-lead ECGs directly to the attending cardiologist using handheld devices is a technologically sound concept without major safety concerns and markedly reducing time to reperfusion in patients with STEMI.

Real-time paramedic compared with blinded physician identification of ST-segment elevation myocardial infarction: results of an observational study

The aim of the study were to determine if paramedics can accurately identify ST-segment elevation myocardial infarction (STEMI) on prehospital 12-lead (PHTL) electrocardiogram and to compare paramedic with blinded physician identification of STEMI. Paramedics identified definite STEMI, or possible acute myocardial infarction but not definite, and nondiagnostic. Two blinded readers (cardiologist and emergency physician) independently categorized each PHTL. A third reviewer assigned final diagnoses and determined whether the PHTL met STEMI criteria. One hundred sixty-six PHTL were acquired over an 8-month period. Fifteen were excluded from analysis. Sixty-two percent of the patients (94/151) were male, mean age was 61.1 years (±14.8 SD, range 20-92 years), and 81% had chest pain. Twenty-five patients (16.6%; 95% confidence interval [CI], 11%-23.5%) had confirmed STEMI and 16 (10.6%) had confirmed non-STEMI acute myocardial infarction. Paramedic sensitivity was 0.80 (95% CI, 0.64-0.96); specificity was 0.97 (95% CI, 0.94-1.00) with positive likelihood ratio of 25.2 and negative likelihood ratio of 0.21. Overall accuracy was similar for paramedic and physician reviewers (0.94, 0.93, 0.95). Highly trained paramedics in an urban emergency medical services system can identify patients with STEMI as accurately as blinded physician reviewers.

The prehospital 12-lead electrocardiogram's effect on time to initiation of reperfusion therapy: a systematic review and meta-analysis of existing literature

The prehospital electrocardiogram (ECG) is becoming the standard of care of suspected cardiac chest pain. We evaluated the evidence regarding the prehospital ECG and sought to quantify the reduction in time to reperfusion therapy attributable to the prehospital ECG. We conducted a systematic review and analyzed studies that were conducted in emergency medical systems relevant to providers in the United States. The papers were limited to studies that reported original data that compared prehospital ECG to no prehospital ECG groups. Four studies containing 99 patients met the inclusion criteria. A meta-analysis of these studies revealed a difference of 24.7 (95% confidence interval, 16.7-32.7) minutes. Providers now have a quantified value of the prehospital ECG based on the best published evidence. In addition, this search showed a relatively low quality and quantity of research on the prehospital ECG.

12-lead Electrocardiograms during Basic Life Support Care

Objectives Prehospital 12-lead electrocardiograms (PTLs) decrease time to thrombolytics. Paramedics have performed them successfully for years, but emergency medical technicians (EMTs) have not typically performed them. To determine whether PTLs could be considered a basic life support (BLS) skill, the authors conducted a pilot study to determine whether scene times are lengthened when EMTs obtain PTLs, whether EMTs can appropriately select patients for PTLs, and what value physicians place on prehospital PTLs. Methods The authors prospectively evaluated PTL performance in four BLS agencies. EMTs provided standard cardiac care to patients on even days. On odd days, they additionally performed a PTL. Scene times of patients receiving a PTL ( n = 77) were compared with scene times of similar patients not receiving one ( n = 100). Results EMTs attempted to perform 101 PTLs, of which 77 were eligible for inclusion. The mean scene time [95% confidence interval] of patients on even days (no 12-lead) was 11.9 [11.0, 12.8] minutes, compared with 16.9 [15.8, 18.0] minutes for patients who received a PTL. Scene times increased by 5.0 [3.6, 6.4] minutes when a PTL was added to the evaluation. Physician feedback was received on 63 of 77 PTLs. Receiving physicians agreed that 59 of 63 (93.6%) patients needed the PTL and found them moderately helpful (3.56 on a 1 to 5 scale). Conclusion When EMTs performed PTLs, scene times increased approximately 5 minutes. Most physicians agreed that the PTL was indicated. PTL acquisition by EMTs appears feasible with slightly lengthened scene times, but evaluation in other BLS agencies is necessary to validate this conclusion.

The utilization of prehospital 12-lead electrocardiograms in the 200 most populous cities in the united states

The utilization of prehospital 12-lead electrocardiograms in the 200 most populous cities in the united states

12-LEAD ELECTROCARDIOGRAMS DURING BASIC LIFE SUPPORT CARE

Objectives. Prehospital 12-lead electrocardiograms (PTLs) decrease time to thrombolytics. Paramedics have performed them successfully for years, but emergency medical technicians (EMTs) have not typically performed them. To determine whether PTLs could be considered a basic life support (BLS) skill, the authors conducted a pilot study to determine whether scene times are lengthened when EMTs obtain PTLs, whether EMTs can appropriately select patients for PTLs, and what value physicians place on prehospital PTLs. Methods. The authors prospectively evaluated PTL performance in four BLS agencies. EMTs provided standard cardiac care to patients on even days. On odd days, they additionally performed a PTL. Scene times of patients receiving a PTL (n = 77) were compared with scene times of similar patients not receiving one (n = 100). Results. EMTs attempted to perform 101 PTLs, of which 77 were eligible for inclusion. The mean scene time [95% confidence interval] of patients on even days (no 12-lead) was 11.9 [11.0, 12.8] minutes, compared with 16.9 [15.8, 18.0] minutes for patients who received a PTL. Scene times increased by 5.0 [3.6, 6.4] minutes when a PTL was added to the evaluation. Physician feedback was received on 63 of 77 PTLs. Receiving physicians agreed that 59 of 63 (93.6%) patients needed the PTL and found them moderately helpful (3.56 on a 1 to 5 scale). Conclusion. When EMTs performed PTLs, scene times increased approximately 5 minutes. Most physicians agreed that the PTL was indicated. PTL acquisition by EMTs appears feasible with slightly lengthened scene times, but evaluation in other BLS agencies is necessary to validate this conclusion.