Prehospital 12-lead ECG Research Articles

Abstract 16067: The Impact of a Prehospital Mobile Cloud ECG Transmission System on Myocardial Damage and Mid-Term Mortality in Patients With ST-Elevation Myocardial Infarction

Background: Guidelines recommend that the door-to-balloon time (DTBT) should be reduced to ninety minutes or less in patients with STEMI. As such, it is critical that ambulance teams are adequately trained and equipped to identify STEMI utilizing ECG recorders and telemetry when necessary. Aims: This single-center study aims to evaluate the impact of the prehospital mobile cloud 12-lead ECG transmission system (SCUNA ® , MEHERGEN GROUP) on reducing DTBT, myocardial damage, and mortality in STEMI patients. Methods: In June 2018, SCUNA were integrated into the regional emergency medical service (EMS) departments in Uki and Kamimashiki cities in Kumamoto, Japan. We examined and compared door-to-catheterization laboratory time (DTCT), DTBT, peak CK, CK-MB levels, as well as 1-year mortality rates of STEMI cases in the four years before and after the introduction of the SCUNA. From June 2014 to May 2022, a total of 338 STEMI patients were transferred to our institute by ambulances from the two EMS departments. After excluding 29 patients with onset to reperfusion times exceeding 24 hours and 66 patients who were transferred without the use of SCUNA following its introduction, 243 consecutive STEMI patients who underwent emergency percutaneous coronary intervention (PCI) were included in the study. The patients were divided into two groups, 130 patients prior to SCUNA introduction (Pre-SCUNA), 113 patients after SCUNA introduction (Post-SCUNA). Results: There were no significant differences in age, gender, past medical history or Killip classification between the two groups. DTCT, DTBT, and onset to reperfusion time (OTRT) were significantly reduced in the Post-SCUNA group compared to the Pre-SCUNA group (Pre-SCUNA: 40 min vs. Post-SCUNA: 25 min; p < 0.01, 71 min vs. 53 min; p < 0.01, and 201 min vs. 166 min; p = 0.02, respectively). No significant differences were observed between peak CK and CK-MB levels in the two groups. Kaplan-Meier analysis revealed that SCUNA did not improve 30-day and 1-year outcomes compared with the Pre-SCUNA groups. Conclusion: While the prehospital mobile cloud ECG transmission system effectively reduced DTBT, it did not lead to a notable reduction in myocardial damage or mortality rates.

Prehospital 12-Lead Electrocardiography System in Oita Assisted Transport of "True" Acute Coronary Syndrome Patients to Optimal Institutes.

Mobile cloud electrocardiography (C-ECG) can reduce the door-to-balloon time of acute coronary syndrome (ACS) patients, so we hypothesized it would also assist in transporting ACS-suspected patients to the optimal institutes.Methods and Results: Initially, 10 fire departments in Oita had 10 ambulances equipped with C-ECG. Ambulance crews recorded a 12-lead ECG from the patient at the first point of contact and transmitted them to 18 hospitals (13 institutions (PCII) with 24-h availability for percutaneous coronary intervention (PCI) and 5 regional core hospitals (RCH) without 24-h PCI) for analysis by a cardiologist. During 41 months, 476 ECGs suspected to be ACS were transmitted and analyzed. Of these, 24 ECGs transmitted to PCII were judged as not requiring PCI, and the patients were directly transported to a RCH (PCII-RCH); 35 ECGs sent to a RCH were judged as requiring PCI, and the patients were directly transported to a PCII (RCH-PCII). The prevalence of cardiovascular disease was significantly higher in the RCH-PCII group than in the PCII-RCH group (P<0.01). There was no significant difference in the door-to-balloon time between the RCH-PCII and the group in which the C-ECG was sent to a PCII and the patients were transported directly to PCII (PCII-PCII) (49±14 vs. 59±20 min, P=0.14). Prehospital 12-lead ECG can assist in transporting ACS-suspect patients to the optimal treatment facility.

Use and impact of the prehospital 12-lead ECG in the primary PCI era (PHECG2): protocol for a mixed-method study

IntroductionUse of the prehospital 12-lead ECG (PHECG) is recommended in patients presenting to emergency medical services (EMS) with suspected acute coronary syndrome (ACS). Prior research found that although PHECG use...

Nonspecific electrocardiographic abnormalities are associated with increased length of stay and adverse cardiac outcomes in prehospital chest pain

BackgroundNonspecific ST-T repolarization (NST) abnormalities alter the ST-segment for reasons often unrelated to acute myocardial ischemia, which could contribute to misdiagnosis or inappropriate treatment. We sought to define the prevalence of NST patterns in patients with chest pain and evaluate how such patterns correlate with the eventual etiology of chest pain and course of hospitalization. MethodsThis was a prospective observational study that included consecutive prehospital chest pain patients from three tertiary care hospitals in the U.S. Two independent reviewers blinded from clinical data audited the prehospital 12-lead ECG for the presence or absence of NST patterns (i.e., right or left bundle branch block, left ventricular hypertrophy with strain pattern, ventricular pacing, ventricular rhythm, or coarse atrial fibrillation). The primary outcome was 30-day major adverse cardiac events (MACE) defined as cardiac arrest, acute heart failure, post-discharge infarction, or all-cause death. ResultsThe final sample included 750 patients (age 59 ± 17, 58% males). A total of 40 patients (5.3%) experienced 30-MACE and 131 (17.5%) had NST patterns. The presence of NST patterns was an independent multivariate predictor of 30-day MACE (9.9% vs. 4.4%, OR = 2.2 [95% CI = 1.1–4.5]. Patients with NST patterns had increased median length of stay (1.0 [IQR 0.5–3] vs. 2.0 [IQR 1–4] days, p < 0.05) independent of the etiology of chest pain. ConclusionsOne in six prehospital ECGs of patients with chest pain has NST patterns. This pattern is associated with increased length of stay and adverse cardiac outcomes, suggesting the need of preventive measures and close follow up in such patients.

Evaluation of NISHIJIN e-textile for 12-lead ECG measurement through automatic ECG analyzer.

The authors are developing e-textile measuring 12-lead ECG signal based using a historical brocade developing technique, NISHIJIN-ORI. In this paper, a NISHIJIN e-textile sensor belt prototype designed for ambulatory measurement (pre-hospital 12-lead ECG measurement) was tested on twenty volunteers. The recorded data was evaluated through the result of commercial automatic ECG analyzer. The obtained results are almost equivalent with the ones obtained through conventional ECG electrodes. However, the results suggest slight modification of the prototype.

Abstract 153: Rural Systems of Care: Real World Observations and Trends in ST Elevation Myocardial Infarction Patient Characteristics, and Correlations of Arrival Mode to Outcomes

Background: Minnesota, North Dakota and South Dakota have been enhancing statewide systems through infrastructure and clinical education regarding ST-elevation myocardial infarction (STEMI) since 2010 in an attempt to equalize access to timely reperfusion in rural areas. A trend in faster time to reperfusion has been observed for STEMI patients who transfer directly to Percutaneous Coronary Intervention (PCI) capable facilities via Emergency Medical Services (EMS) and receive a pre-hospital 12-lead ECG in comparison to those who first present to a non PCI capable facility. This improved time to STEMI recognition and reperfusion may be associated with improved outcomes. Methods: Data was collected via ACTION Registry-GWTG from 2012-2015. The cohort was defined as STEMI patients who received PPCI with interfacility transfer (n=1010) and without (n=376) and who receive a pre-hospital 12-lead ECG (n=1078) and do not (n=308). The association between mode of transport, time to PPCI, and outcomes including LV function, in hospital clinical events, and in-hospital mortality were analyzed by unadjusted association. Multivariable adjustment was performed using covariates from the previously developed and validated ACTION mortality model to determine the independent association between arrival mode and outcomes. Results: The direct transfer group demonstrated shorter cumulative times (79 vs. 145 min., p=&lt;0.001) to coronary reperfusion as compared to the interfacility transfer group. The pre-hospital ECG group experienced a shorter time to transfer (40 vs. 55 min., p=&lt;0.001) to a PPCI center consistent with earlier system recognition and activation for a STEMI patient. The direct transfer and pre-hospital ECG groups had a statistically significant less risk of in-hospital cardiogenic shock, congestive heart failure, cardiac arrest and death as a composite end-point, p=0.011 &amp; &lt;0.001 respectively. During the years of 2012 to 2015, the performance of pre-hospital ECGs has increased. Conclusion: Implementation of Mission Lifeline programming was associated with significantly lower risk of in-hospital shock, congestive heart failure, cardiac arrest and death in STEMI patients presenting via EMS through increased utilization of pre hospital ECG, education, and hospital triage and procedural PPCI streamlining.

USEFULNESS OF PRE-HOSPITAL ECG IN STEMI PATIENTS PRESENTING DIRECTLY TO A PRIMARY PCI CENTER

Shorter reperfusion times are associated with improved clinical outcomes in STEMI patients referred for primary PCI. Patients presenting to hospitals without PCI facilities experience additional delays associated with transportation to primary PCI centers. The use of pre-hospital ECG to identify patients with STEMI may help reduce reperfusion times by taking patients directly to hospitals performing primary PCI. Whether pre-hospital ECG may also improve reperfusion delays in patients who would normally present directly to a primary PCI center is unclear. Between July 2012 and June 2013, 689 patients were admitted with a diagnosis of STEMI in a single tertiary cardiology care center. A total of 286 patients were excluded: 159 treated with thrombolysis, 65 with late presentation, 28 referred from outside a radius of 90 min transport time, 7 developing STEMI in-hospital, 6 with spontaneous ST-segment resolution, and 21 patients with missing data. We compared 161 patients who underwent pre-hospital 12-lead ECG in the ambulance and were oriented directly to the primary PCI-capable center (pre-hospital ECG group) with 242 patients who presented to a referral hospital or directly to the primary PCI center but did not benefit from pre-hospital ECG (control group). Median first door-to-balloon (DTB) time was shorter in the pre-hospital ECG group (46 min vs 102 min;p<0.001). Pre-hospital ECG also reduced median first-medical-contact-to-balloon from 115 min to 84 min (p<0.001). Proportion of patients with DTB time < 90 minutes was 98% in the pre-hospital ECG group and 45% in the control group (p<0.001). Total ischemic time, defined by the time between symptom onset and device activation, was also reduced by a median of 111 minutes in patients with pre-hospital ECG (140 vs 246 minutes; p<0.001). In an analysis restricted to patients living on the territory of the primary PCI center, pre-hospital ECG significantly reduced median DTB (80 min vs 50 min; p<0.001), median first-medical-contact-to-balloon (102 min to 79 min; p<0.001) and median total ischemic time (220 min vs 116 min;p<0.001). Pre-hospital ECG significantly reduces reperfusion delays in STEMI patients. Benefits are seen in all patients, including those who would normally present directly to a primary PCI center. Broader use of this technology should be supported and efforts should be made to encourage patients to use emergency medical service if they experience chest pain suggestive of heart attack.

Detection of culprit coronary lesion location in pre-hospital 12-lead ECG

BackgroundPre-hospital 12-lead ECG interpretation is important because pre-hospital activation of the coronary catheterization laboratory reduces ST-segment elevation myocardial infarction (STEMI) discovery-to-treatment time. In addition, some ECG features indicate higher risk in STEMI such as proximal left anterior descending (LAD) culprit lesion location. The challenging nature of the pre-hospital environment can lead to noisier ECGs which make automated STEMI detection difficult. We describe an automated system to classify lesion location as proximal LAD, LAD, right coronary artery (RCA) and left circumflex (LCx) and test the performance on pre-hospital 12-lead ECG. MethodsThe overall classifier was designed from three linked classifiers to separate LAD from non-LAD (RCA or LCx) in the first step, RCA from LCx in a second classifier and proximal from non-proximal LAD in the third classifier. The proximal LAD classifier was designed for high specificity because the output may be used in the decision to modify treatment. The LCx classifier was designed for high specificity because RCA is dominant in most people. The system was trained on a set of emergency department ECGs (n=181) and tested on a set of pre-hospital ECGs (n=80). Both sets were based on a sequential sample starting with symptoms suggesting acute coronary syndromes. Culprit lesion location was determined from coronary catheterization laboratory reports. Inclusion criteria included STEMI interpretation by computer and culprit lesion with 70% or more narrowing. Algorithm accuracy was measured on the test set by sensitivity (SE), specificity (SP), and positive predictive value (PPV). ResultsSE, SP and PPV were 50, 100 and 100% respectively for proximal LAD lesion location; 90, 100 and 100% for all LAD; 98, 72 and 78% for RCA; and 50, 98 and 90% for LCx. Specificity and PPV were high for proximal LAD, LAD and LCx. Specificity and PPV are not as high for RCA by design since the RCA-LCx tradeoff favors high specificity in LCx. ConclusionAlthough our test database is not large, algorithm performance suggests culprit lesion location can be reliably determined from pre-hospital ECG. Further research is needed however to evaluate the impact of automated culprit lesion location on patient treatment and outcomes.

Effects of prehospital 12-lead ECG on processes of care and mortality in acute coronary syndrome: a linked cohort study from the Myocardial Ischaemia National Audit Project

ObjectiveTo describe patterns of prehospital ECG (PHECG) use and determine its association with processes and outcomes of care in patients with ST-elevation myocardial infarction (STEMI) and non-STEMI.MethodsPopulation-based linked cohort study...

Cellular technology improves transmission success of pre-hospital electrocardiograms

Study objectiveIn rural settings, long distances and transport times pose a challenge for achieving early reperfusion goals in patients with ST-elevation myocardial infarction (STEMI). This study investigated the association between the method of pre-hospital 12-lead ECG transmission (radio transmission vs. cellular phone transmission) and the success of transmission and legibility of 12-lead ECGs in a rural setting. MethodsObservational study of pre-hospital 12-lead ECG transmission to the emergency department (ED) in a predominantly rural area. Success of transmission and the legibility of the 12-lead ECG were analyzed to identify barriers to 12-lead ECG transmission and reasons for failed transmission. ResultsEmergency medical services performed ECGs on 1140 patients, 917 of which they attempted to transmit, including 43 cases requiring emergent catheterization. Twelve-lead ECG transmission was successful in 236 (70%) of 337 radio attempts and 441 (76%) of 580 cellular attempts (difference 6.0%, 95% CI 1.1-12.1). Legibility increased from 164 (49%) of 337 radio attempts to 389 (67%) of 580 cellular attempts (difference 18.4%, 95% CI 11.8–24.9). ConclusionThe success of transmission and legibility of 12-lead ECGs was significantly higher with cellular technology by emergency medical service agencies in comparison to radio transmission. In rural settings with lengthy transport times, utilization of cellular technology for transmission of pre-hospital 12-lead ECGs may improve door-to-balloon times for STEMI patients.

Door-to-needle time for administration of fibrinolytics in acute myocardial infarction in Cape Town.

To determine the current door-to-needle time for the administration of fibrinolytics for acute myocardial infarction (AMI) in emergency centres (ECs) at three hospitals in Cape Town, and to compare it with the American Heart Association/American College of Cardiology (AHA/ACC) recommendation of 30 minutes as a marker of quality of care. A retrospective review of case notes from January 2008 to July 2010 of all patients receiving thrombolytics for AMI in the ECs of three Cape Town hospitals. The total door-to-needle time was calculated and patient demographics and presentation, physician qualification, clinical symptomology and reasons for delays in thromobolytic administration were analysed. A total of 372 patients with acute ST elevation myocardial infarction (STEMI) were identified; 161 patients were eligible for the study. The median door-to-needle time achieved was 54 minutes (range 13 - 553 mins). A door-to-needle time of 30 minutes or less was achieved in 33 (20.5%) patients; 51.3% of the patients arrived by ambulance; 34% of patients had a pre-hospital 12-lead ECG; and 88.8% had typical symptoms of myocardial infarction. Medical officers administered thrombolytics to 44.7% of the patients. The predominant infarct location on ECG was inferior (55.9%). A significant number of patients were not thrombolysed within 30 minutes of presentation. The lack of senior doctors, difficulty interpreting ECGs, atypical presentations and EC system delays prolonged the door-to-needle time in this study.

TCT-345: Impact of the Novel Mobile Telemedicine System in Real- time Transmission of Prehospital 12-lead ECG for ST-segment Elevation Acute myocardial infarction

TCT-345: Impact of the Novel Mobile Telemedicine System in Real- time Transmission of Prehospital 12-lead ECG for ST-segment Elevation Acute myocardial infarction

438 Use of pre-hospital ECG improves time to reperfusion in STEMI patients

438 Use of pre-hospital ECG improves time to reperfusion in STEMI patients

Kommentar zu den Leitlinien 2010 zur kardiopulmonalen Reanimation des European Resuscitation Council

Administer chest compressions (minimum 100/min, minimum 5 cm depth) at a ratio of 30:2 with ventilation (tidal volume 500-600 ml, inspiration time 1 s, F(I)O₂ if possible 1.0). Avoid any interruptions in chest compressions. After every single defibrillation attempt (initially biphasic 120-200 J, monophasic 360 J, subsequently with the respective highest energy), chest compressions are initiated again immediately for 2 min independent of the ECG rhythm. Tracheal intubation is the optimal method for securing the airway during resuscitation but should be performed only by experienced airway management providers. Laryngoscopy is performed during ongoing chest compressions; interruption of chest compressions for a maximum of 10 s to pass the tube through the vocal cords. Supraglottic airway devices are alternatives to tracheal intubation. Drug administration routes for adults and children: first choice i.v., second choice intraosseous (i.o.). Vasopressors: 1 mg epinephrine every 3-5 min i.v. After the third unsuccessful defibrillation amiodarone (300 mg i.v.), repetition (150 mg) possible. Sodium bicarbonate (50 ml 8.4%) only for excessive hyperkaliemia, metabolic acidosis, or intoxication with tricyclic antidepressants. Consider aminophylline (5 mg/kgBW). Thrombolysis during spontaneous circulation only for myocardial infarction or massive pulmonary embolism; during on-going cardiopulmonary resuscitation (CPR) only when indications of massive pulmonary embolism. Active compression-decompression (ACD-CPR) and inspiratory threshold valve (ITV-CPR) are not superior to good standard CPR. Most effective improvement of outcome by prevention of full cardiorespiratory arrest. Basic life support: initially five rescue breaths, followed by chest compressions (100-120/min depth about one third of chest diameter), compression-ventilation ratio 15:2. Foreign body airway obstruction with insufficient cough: alternate back blows and chest compressions (infants), or abdominal compressions (children >1 year). Treatment of potentially reversible causes: ("4 Hs and 4 Ts") hypoxia and hypovolaemia, hypokalaemia and hyperkalaemia, hypothermia, and tension pneumothorax, tamponade, toxic/therapeutic disturbances, thrombosis (coronary/pulmonary). Advanced life support: adrenaline (epinephrine) 10 µg/kgBW i.v. or i.o. every 3-5 min. Defibrillation (4 J/kgBW; monophasic or biphasic) followed by 2 min CPR, then ECG and pulse check. NEWBORNS: Initially inflate the lungs with bag-valve mask ventilation (p(AW) 20-40 cmH₂O). If heart rate remains <60/min, start chest compressions (120 chest compressions/min) and ventilation with a ratio 3:1. Maintain normothermia in preterm babies by covering them with foodgrade plastic wrap or similar. POSTRESUSCITATION PHASE: Early protocol-based intensive care stabilization; initiate mild hypothermia early regardless of initial cardiac rhythm [32-34°C for 12-24 h (adults) or 24 h (children); slow rewarming (<0.5°C/h)]. Consider percutaneous coronary intervention (PCI) in patients with presumed cardiac ischemia. Prediction of CPR outcome is not possible at the scene, determine neurological outcome <72 h after cardiac arrest with somatosensory evoked potentials, biochemical tests and neurological examination. ACUTE CORONARY SYNDROME: Even if only a weak suspicion of an acute coronary syndrome is present, record a prehospital 12-lead ECG. In parallel to pain therapy, administer aspirin (160-325 mg p.o. or i.v.) and clopidogrel (75-600 mg depending on strategy); in ST-elevation myocardial infarction (STEMI) and planned PCI also prasugrel (60 mg p.o.). Antithrombins, such as heparin (60 IU/kgBW, max. 4000 IU), enoxaparin, bivalirudin or fondaparinux depending on the diagnosis (STEMI or non-STEMI-ACS) and the planned therapeutic strategy. In STEMI define reperfusion strategy depending on duration of symptoms until PCI, age and location of infarction. TRAUMA: In severe hemorrhagic shock, definitive control of bleeding is the most important goal. For successful CPR of trauma patients a minimal intravascular volume status and management of hypoxia are essential. Aggressive fluid resuscitation, hyperventilation and excessive ventilation pressure may impair outcome in patients with severe hemorrhagic shock. Any CPR training is better than nothing; simplification of contents and processes is the main aim.

Improving Use of Prehospital 12-Lead ECG for Early Identification and Treatment of Acute Coronary Syndrome and ST-Elevation Myocardial Infarction

Performance of prehospital ECGs expedites identification of ST-elevation myocardial infarction and reduces door-to-balloon times for patients receiving reperfusion therapy. To fully realize this benefit, emergency medical service performance must be measured and used in feedback reporting and quality improvement. This quasi-experimental design trial tested an approach to improving emergency medical service prehospital ECGs using feedback reporting and quality improvement interventions in 2 cities' emergency medical service agencies and receiving hospitals. All patients age > or =30 years, calling 9-1-1 with possible acute coronary syndrome, were included. In total, 6994 patients were included: 1589 patients in the baseline period without feedback and 5405 in the intervention period when there were feedback reports and quality improvement interventions. Mean age was 66+/-17 years, and women represented 51%. Feedback and quality improvement increased prehospital ECG performance for patients with acute coronary syndrome from 76% to 93% (P=<0.0001) and for patients with ST-elevation myocardial infarction from 77% to 99% (P=<0.0001). Aspirin administration increased from 75% to 82% (P=0.001), but the median total emergency medical service run time remained the same at 22 minutes. The proportion of patients with door-to-balloon times of < or =90 minutes increased from 27% to 67% (P=0.006). Feedback reports and quality improvement improved prehospital ECG performance for patients with acute coronary syndrome and ST-elevation myocardial infarction and increased aspirin administration without prehospital transport delays. Improvements in door-to-balloon times were also seen.

Reperfusion of old or new: left bundle branch block?

Reperfusion options for patients suffering ST-elevation myocardial infarction (STEMI) have developed significantly over recent years and now include both thrombolytic therapy and primary percutaneous coronary intervention (PPCI). This system of care means that patients presenting with STEMI can be transferred directly to a heart-attack centre to receive immediate PPCI. National guidelines state that pre-hospital thrombolysis (PHT) is a crucial part of STEMI reperfusion where PPCI cannot be delivered within 90 minutes of diagnosis. There is evidence describing rates of in-hospital thrombolysis in both MI with ST elevation and MI with LBBB. There is a knowledge gap however describing treatment of MI with LBBB based upon a pre-hospital 12-lead ECG. This paper describes the challenges around PHT in the context of LBBB and offers potential solutions that may provide assistance in making the decision to undertake PHT or not.

Investigation of paramedics' compliance with clinical practice guidelines for the management of chest pain

BackgroundAcute coronary syndromes remain a leading cause of preventable early deaths. However, previous studies have indicated that paramedics' compliance with chest pain protocols is suboptimal and that many patients do...

Prehospital 12-Lead ECG to Triage ST-Elevation Myocardial Infarction and Emergency Department Activation of the Infarct Team Significantly Improves Door-to-Balloon Times

Background— American College of Cardiology/American Heart Association guidelines recommend &gt;75% of patients with an ST-elevation myocardial infarction receive primary percutaneous coronary interventions (PPCI) within 90 minutes. Despite these recommendations, this goal has been difficult to achieve. Methods and Results— We conducted a prospective interventional study involving 349 patients undergoing PPCI at a single tertiary referral institution to determine the impact of prehospital 12-lead ECG triage and emergency department activation of the infarct team on door-to-balloon time (D2BT). The median D2BT of all patients (n=107) who underwent PPCI after field ECG and emergency department activation of the infarct team (MonashHEART Acute Myocardial Infarction [MonAMI] group) was 56 minutes (interquartile range, 36.5 to 70) compared with the median time of a contemporary group (n=122) undergoing PPCI during the same period but not receiving field triage (non-MonAMI group) of 98 minutes (73 to 126.45). The median D2BT time of 120 consecutive patients who underwent PPCI before initiation of the project (pre-MonAMI group) was 101.5 minutes (72.5 to 134; P &lt;0.001). The proportion of patients who achieved a D2BT of ≤90 minutes increased from 39% in the pre-MonAMI group and 45% in the non-MonAMI group to 93% in the MonAMI group ( P &lt;0.001). Conclusions— The performance of prehospital 12-lead ECG triage and emergency department activation of the infarct team significantly improves D2BT and results in a greater proportion of patients achieving guideline recommendations.

Collaborative decision-making between paramedics and CCU nurses based on 12-lead ECG telemetry expedites the delivery of thrombolysis in ST elevation myocardial infarction

Objectives:To describe a prehospital thrombolysis (PHT) and expedited inhospital thrombolysis (IHT) programme in south-east Scotland using prehospital 12-lead ECG recordings transmitted by telemetry and autonomous paramedic-administered thrombolysis with decision support...

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.