To transmit or not to transmit: how good are emergency medical personnel in detecting STEMI in patients with chest pain?

Could paramedics use the HEART Pathway to identify patients at low-risk of myocardial infarction in the prehospital setting?

In the Emergency Department, patients with suspected myocardial infarction can be risk stratified using the HEART pathway, which has recently been amended for prehospital use and modified for the incorporation of a high-sensitivity cardiac troponin test. In a prospective analysis, the performance of both HEART pathways in the prehospital setting, with a high-sensitivity cardiac troponin test using 3 different thresholds, was evaluated for major adverse cardiac events at 30 days. We found that both low-risk HEART pathways, when using the most conservative cardiac troponin thresholds, approached but did not reach accepted rule-out performance in the Emergency Department.

Paramedic Ability in Interpreting Electrocardiogram with ST-segment Elevation Myocardial Infarction (STEMI) in Saudi Arabia

Objective

To evaluate paramedic ability in recognizing 12-lead Electrocardiogram (ECG) with ST-segment Elevation myocardial infarction (STEMI) in Saudi Arabia.

Methods

This is a quantitative exploratory cross-sectional study using an electronic survey of paramedics was conducted between June and September 2021. The survey included demographics, educational and clinical experiences, and multiple 12-lead ECG strip questions to assess participants’ ability to recognize STEMI. We reported the overall sensitivity, specificity, and correct proportions with 95% Confidence Intervals (CI).

Results

Eighty-four paramedics completed the survey, and 65% of them were between 24 and 29 years old, with a median, of three years of field experience. Overall sensitivity and specificity were 58.39% (95% CI, 50.4% to 66.1%) and 29.01% (95% CI, 25.15% to 33.1%), respectively. In total, 67.1% correctly identified inferior STEMI, whereas only 50% correctly identified lateral STEMI. Both STEMIs were correctly identified by 41%, and the majority misinterpreted STEMI mimics (ECG rhythms with similar ECG morphology to STEMI). The proportion who correctly recognized left bundle branch block was 14.8%, pericarditis was 10.9%, and ventricular pacing was 1.4%. However, almost third of participants correctly identified right bundle branch block (32.9%) and left ventricle hypertrophy (30.7%). Overall, there was no correlation between the correct ECG interpretation of STEMIs and educational and clinical experiences.

Conclusion

Paramedics were able to identify STEMI events in prehospital settings with moderate sensitivity and low specificity with limited ability to differentiate between STEMI and STEMI mimics. Therefore, additional training in ECG interpretation could improve their clinical decision-making, and to ensure that proper care and treatment is provided. Further research on a large, representative sample of paramedics across the country could provide more definitive evidence to establish a greater degree of accuracy in detecting STEMI in prehospital settings.

Systematic Review and Meta-Analysis of Diagnostic Accuracy to Identify ST-Segment Elevation Myocardial Infarction on Interpretations of Prehospital Electrocardiograms

Background: The aim of this study was to assess and discuss the diagnostic accuracy of prehospital ECG interpretation through systematic review and meta-analyses.

Methods and Results: Relevant literature published up to July 2020 was identified using PubMed. All human studies of prehospital adult patients suspected of ST-segment elevation myocardial infarction in which prehospital electrocardiogram (ECG) interpretation by paramedics or computers was evaluated and reporting all 4 (true-positive, false-positive, false-negative, and true-negative) values were included. Meta-analyses were conducted separately for the diagnostic accuracy of prehospital ECG interpretation by paramedics (Clinical Question [CQ] 1) and computers (CQ2). After screening, 4 studies for CQ1 and 6 studies for CQ2 were finally included in the meta-analysis. Regarding CQ1, the pooled sensitivity and specificity were 95.5% (95% confidence interval [CI] 82.5–99.0%) and 95.8% (95% CI 82.3–99.1%), respectively. Regarding CQ2, the pooled sensitivity and specificity were 85.4% (95% CI 74.1–92.3%) and 95.4% (95% CI 87.3–98.4%), respectively.

Conclusions: This meta-analysis suggests that the diagnostic accuracy of paramedic prehospital ECG interpretations is favorable, with high pooled sensitivity and specificity, with an acceptable estimated number of false positives and false negatives. Computer-assisted ECG interpretation showed high pooled specificity with an acceptable estimated number of false positives, whereas the pooled sensitivity was relatively low.

Comparison of the outcomes of EMS vs. Non-EMS transport of patients with ST-segment elevation myocardial infarction (STEMI) in Southern Iran: a population-based study

BACKGROUND

In the medical management of acute myocardial infarction, the transport of patients and primary care provided by emergency medical technicians (EMTs) and paramedics are effective in reducing the mortality and disabilities. Therefore, the present study aimed to compare the outcomes of emergency medical services (EMS) vs. non-EMS transport of patients with ST-segment elevation myocardial infarction (STEMI) in southern Iran.

METHODS

This is an analytical, cross-sectional study. The study population consisted of the individuals registered in Fasa Registry on Acute Myocardial Infarction (FaRMI) in the south of Iran. 2244 patients with STEMI were included in the study. Statistical analyses were performed using Chi-Square test and independent t-test at a significance level of P < 0.05 in SPSS 22.

RESULTS

Out of the 2244 patients with STEMI, 1552 (69.16%) were male and 672 patients (29.94%) were female. 934(41.62%) patients used EMS transport to the hospital, while 1310 (58.37%) patients used non-EMS transport to the hospital. A total of 169 patients with STEMI (7.26%) expired (out-of-hospital cardiac arrest); of them, 113 (66.86%) patients did not use EMS transport to the hospital. Successful cardiopulmonary resuscitation (CPR) was performed on 52 patients who used EMS transport. 27 patients also received an effective DC shock due to ventricular fibrillation (VF). Of the total number of patients, 49 had a stroke; among them, 37(75.51%) patients did not use EMS transport.

CONCLUSION

In the present study, the death rate in patients with acute myocardial infarction who used EMS transport was lower than those who used non-EMS transport. The health system managers and policymakers in the healthcare systems are recommended to take the necessary measures to increase public health awareness and knowledge about the use of EMS and consequently reduce the death rate and complications of acute myocardial infarction.

Emergency activations for chest pain and ventricular arrhythmias related to regional COVID-19 across the US

Evidence that patients may avoid healthcare facilities for fear of COVID-19 infection has heightened the concern that true rates of myocardial infarctions have been under-ascertained and left untreated. We analyzed data from the National Emergency Medical Services Information System (NEMSIS) and incident COVID-19 infections across the United States (US) between January 1, 2020 and April 30, 2020. Grouping events by US Census Division, multivariable adjusted negative binomial regression models were utilized to estimate the relationship between COVID-19 and EMS cardiovascular activations. After multivariable adjustment, increasing COVID-19 rates were associated with less activations for chest pain and non-ST-elevation myocardial infarctions. Simultaneously, increasing COVID-19 rates were associated with more activations for cardiac arrests, ventricular fibrillation, and ventricular tachycardia. Although direct effects of COVID-19 infections may explain these discordant observations, these findings may also arise from patients delaying or avoiding care for myocardial infarction, leading to potentially lethal consequences.

What Adult Electrocardiogram (ECG) Diagnoses or Findings are Most Important for Advanced Care Paramedics to Know?

Introduction: The interpretation of electrocardiograms (ECGs) is an essential competency in modern paramedicine. Although educational guidelines for paramedic ECG interpretation exist, they are broad, not evidence-based, and lack prioritization in a prehospital clinical context. We conducted this study to gain consensus among stakeholders (EMS physicians, paramedic educators, and paramedic clinicians) regarding which ECG diagnoses or findings are most important for a practising advanced care paramedic to know. 

Methods: This study was an internet-based Delphi survey. We purposefully sampled participants in pairs (physician/paramedic) from all 10 Canadian provinces. Individuals rated a previously developed comprehensive list of emergency ECG diagnoses or findings on the importance of paramedic recognition and impact on prehospital care using a 4-point Likert scale. The consensus was achieved with a minimum of 75% agreement on Likert rating for a single diagnosis or finding during survey rounds one to three. When consensus was not reached, stability was defined as a shift of individual ratings between rounds of 20% or less.

Results: All 20 participants completed the first and second rounds of the survey, and 17 (85%) completed three rounds. Overall, 32 (26.4%) of 121 potentially important ECG diagnoses or findings reached consensus, 2 (1.7%) reached stability and 87 (71.9%) reached neither consensus nor stability. Twenty-one (17.4%) diagnoses or findings were considered “Very Important”, six (4.9%) “Important”, and five (4.1%) “Minimally Important”. In the first round of the survey, the mean rating of the importance of a paramedic knowing a specific ECG diagnosis or finding was lower in the physician group than the paramedic group on 85 (72%) of 118 initial diagnoses or findings.

Conclusion: We have created a list of ECG diagnoses or findings prioritized for the prehospital context that may assist paramedic educators in focusing on educational interventions. Many ECG diagnoses or findings failed to reach consensus or stability, demonstrating potential disagreement regarding clinical expectations for ECG knowledge among paramedics or physicians.

Effect of Real-Time Physician Oversight of Prehospital STEMI Diagnosis on ECG-Inappropriate and False Positive Catheterization Laboratory Activation

Background

ST-elevation myocardial infarction diagnosis at first medical contact (FMC) and prehospital cardiac catheterization laboratory (CCL) activation are associated with reduced total ischemic time and therefore have become the dominant ST-elevation myocardial infarction referral method in primary percutaneous coronary intervention systems. We sought to determine whether physician oversight was associated with improved diagnostic performance in a prehospital CCL activation system and what effect the additional interpretation has on treatment delay.

Methods

Between 2012 and 2015, all patients in 2 greater Montreal catchment areas with a chief symptom of chest paint or dyspnea had an in-the-field electrocardiogram (ECG). A machine diagnosis of "acute myocardial infarction" resulted either in automatic CCL (automated cohort without oversight) or transmission of the ECG to the receiving centre emergency physician for reinterpretation before CCL activation. System performance was assessed in terms of the proportion of false positive and inappropriate activations (IA), as well as the proportion of patients with FMC-to-device times ≤ 90 minutes.

Results

Four hundred twenty-eight (428) activations were analyzed (311 automated; 117 with physician oversight). Physician oversight tended to decrease IAs (7% vs 3%; P = 0.062), but was also associated with a smaller proportion of patients achieving target FMC-to-device (76% vs 60%; P < 0.001). There was no significant effect on the proportion of false positive activation.

Conclusions

Real-time physician oversight might be associated with fewer IAs, but also appears to have a deleterious effect on FMC-to-device performance. Identifying predictors of IA could improve overall performance by selecting ECGs that merit physician oversight and streamlining others. Larger clinical studies are warranted.

Prehospital use of a modified HEART Pathway and point-of-care troponin to predict cardiovascular events

The HEART Pathway is a validated risk stratification protocol for Emergency Department patients with chest pain that has yet to be tested in the prehospital setting. This study seeks to test the performance of a prehospital modified HEART Pathway (PMHP). A prospective cohort study of adults with chest pain without ST-segment elevation myocardial infarction was conducted at three EMS agencies between 12/2016-1/2018. To complete a PMHP assessment, paramedics drew blood, measured point-of-care (POC) troponin (i-STAT; Abbott Point of Care) and calculated a HEAR score. Patients were stratified into three groups: high-risk based on an elevated troponin, low-risk based on a HEAR score <4 with a negative troponin, or moderate risk for a HEAR score ≥4 with a negative troponin. Sensitivity, specificity, negative and positive predictive values of the PMHP for detection of major adverse cardiac events (MACE: cardiac death, MI, or coronary revascularization) at 30-days were calculated. A total of 506 patients were accrued, with PMHP completed in 78.1% (395/506). MACE at 30-days occurred in 18.7% (74/395). Among these patients, 7.1% (28/395) were high risk yielding a specificity and PPV for 30-day MACE of 96.6% (95%CI: 94.0–98.3%) and 60.7% (95%CI: 40.6–78.6%) respectively. Low-risk assessments occurred in 31.4% (124/395), which were 90.5% (95%CI: 81.5–96.1%) sensitive for 30-day MACE with a NPV of 94.4% (95%CI: 88.7–97.7%). Moderate-risk assessments occurred in 61.5% (243/395), of which 20.6% had 30-day MACE. The PMHP is able to identify high-risk and low-risk groups with high specificity and negative predictive value for 30-day MACE.

Pre-hospital triage performance and emergency medical services nurse's field assessment in an unselected patient population attended to by the emergency medical services: a prospective observational study

BACKGROUND

In Sweden, the rapid emergency triage and treatment system (RETTS-A) is used in the pre-hospital setting. With RETTS-A, patients triaged to the lowest level could safely be referred to a lower level of care. The national early warning score (NEWS) has also shown promising results internationally. However, a knowledge gap in optimal triage in the pre-hospital setting persists. This study aimed to evaluate RETTS-A performance, compare RETTS-A with NEWS and NEWS 2, and evaluate the emergency medical service (EMS) nurse's field assessment with the physician's final hospital diagnosis.

METHODS

A prospective, observational study including patients (≥16 years old) transported to hospital by the Gothenburg EMS in 2016. Three comparisons were made: 1) Combined RETTS-A levels orange and red (high acuity) compared to a predefined reference emergency, 2) RETTS-A high acuity compared to NEWS and NEWS 2 score ≥ 5, and 3) Classification of pre-hospital nurse's field assessment compared to hospital physician's diagnosis. Outcomes of the time-sensitive conditions, mortality and hospitalisation were examined. The statistical tests included Mann-Whitney U test and Fisher's exact test, and several binary classification tests were determined.

RESULTS

Overall, 4465 patients were included (median age 69 years; 52% women). High acuity RETTS-A triage showed a sensitivity of 81% in prediction of the reference patient with a specificity of 64%. Sensitivity in detecting a time-sensitive condition was highest with RETTS-A (73%), compared with NEWS (37%) and NEWS 2 (35%), and specificity was highest with NEWS 2 (83%) when compared with RETTS-A (54%). The negative predictive value was higher in RETTS-A (94%) compared to NEWS (91%) and NEWS 2 (92%). Eleven per cent of the final diagnoses were classified as time-sensitive while the nurse's field assessment was appropriate in 84% of these cases.

CONCLUSIONS

In the pre-hospital triage of EMS patients, RETTS-A showed sensitivity that was twice as high as that of both NEWS and NEWS 2 in detecting time-sensitive conditions, at the expense of lower specificity. However, the proportion of correctly classified low risk triaged patients (green/yellow) was higher in RETTS-A. The nurse's field assessment of time-sensitive conditions was appropriate in the majority of cases.

2019 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Guidelines on the Acute Management of ST-Elevation Myocardial Infarction: Focused Update on Regionalization and Reperfusion

Rapid reperfusion of the infarct-related artery is the cornerstone of therapy for the management of acute ST-elevation myocardial infarction (STEMI). Canada's geography presents unique challenges for timely delivery of reperfusion therapy for STEMI patients. The Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology STEMI guideline was developed to provide advice regarding the optimal acute management of STEMI patients irrespective of where they are initially identified: in the field, at a non-percutaneous coronary intervention-capable centre or at a percutaneous coronary intervention-capable centre. We had also planned to evaluate and incorporate sex and gender considerations in the development of our recommendations. Unfortunately, inadequate enrollment of women in randomized trials, lack of publication of main outcomes stratified according to sex, and lack of inclusion of gender as a study variable in the available literature limited the feasibility of such an approach. The Grading Recommendations, Assessment, Development, and Evaluation system was used to develop specific evidence-based recommendations for the early identification of STEMI patients, practical aspects of patient transport, regional reperfusion decision-making, adjunctive prehospital interventions (oxygen, opioids, antiplatelet therapy), and procedural aspects of mechanical reperfusion (access site, thrombectomy, antithrombotic therapy, extent of revascularization). Emphasis is placed on integrating these recommendations as part of an organized regional network of STEMI care and the development of appropriate reperfusion and transportation pathways for any given region. It is anticipated that these guidelines will serve as a practical template to develop systems of care capable of providing optimal treatment for a wide range of STEMI patients.

Diagnostic accuracy of prehospital electrocardiograms interpreted remotely by emergency physicians in myocardial infarction patients

BACKGROUND

Prehospital 12‑lead electrocardiogram (ECG) is the most widely used screening tool for recognition of ST-segment elevation myocardial infarction (STEMI). However, prehospital diagnosis of STEMI based solely on ECGs can be challenging.

OBJECTIVES

To evaluate the ability of emergency department (ED) physicians to accurately interpret prehospital 12‑lead ECGs from a remote location.

METHODS

All suspected prehospital STEMI patients who were transported by EMS and underwent angiography between 2006 and 2014 were included. We reviewed prehospital ECGs and grouped them based on: 1) presence or absence of a culprit artery lesion following angiography; and 2) whether they met the 3rd Universal Definition of Myocardial Infarction. We also described characteristics of ECGs that were misinterpreted by ED physicians.

RESULTS

A total of 625 suspected STEMI cases were reviewed. Following angiography, 94% (590/625) of patients were found having a culprit artery lesion, while 6% (35/625) did not. Among these 35 patients, 24 had ECGs that mimicked STEMI criteria and 9 had non-ischemic signs. Upon ECG reinterpretation, 92% (577/625) had standard STEMI criteria while 8% (48/625) did not. Among these 48 patients, 35 had ischemic signs ECGs and 13 did not. Characteristics of misinterpreted ECGs included pericarditis, early repolarization, STE > 1 mm (1‑lead only), and negative T-wave.

CONCLUSIONS

Remote interpretation of prehospital 12‑lead ECGs by ED physicians was a useful diagnostic tool in this EMS system. Even if the rate of ECG misinterpretation is low, there is still room for ED physicians operating from a remote location to improve their ability to accurately diagnose STEMI patients.

Achieving the earliest possible reperfusion in patients with acute coronary syndrome: a current overview

Acute coronary syndrome (ACS) remains one of the leading causes of mortality worldwide. Appropriate management of ACS will lead to a lower incidence of cardiac arrest. Percutaneous coronary intervention (PCI) is the first-line treatment for patients with ACS. PCI techniques have become established. Thus, the establishment of a system of health care in the prehospital and emergency department settings is needed to reduce mortality in patients with ACS. In this review, evidence on how to achieve earlier diagnosis, therapeutic intervention, and decision to reperfuse with a focus on the prehospital and emergency department settings is systematically summarized. The purpose of this review is to generate current, evidence-based consensus on scientific and treatment recommendations for health care providers who are the initial points of contact for patients with signs and symptoms suggestive of ACS.

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 ± 18.1 minutes. Unwanted CCL activations were more likely to involve men aged >65 years 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.

Sustained Performance of a "Physicianless" System of Automated Prehospital STEMI Diagnosis and Catheterization Laboratory Activation

BACKGROUND

Treatment times for primary percutaneous coronary intervention frequently exceed the recommended maximum delay. Automated "physicianless" systems of prehospital cardiac catheterization laboratory (CCL) activation show promise, but have been met with resistance over concerns regarding the potential for false positive and inappropriate activations (IAs).

METHODS

From 2010 to 2015, first responders performed electrocardiograms (ECGs) in the field for all patients with a complaint of chest pain or dyspnea. An automated machine diagnosis of "acute myocardial infarction" resulted in immediate CCL activation and direct transfer without transmission or human reinterpretation of the ECG prior to patient arrival. Any activation resulting from a nondiagnostic ECG (no ST-elevation) was deemed an IA, whereas activations resulting from ECG's compatible with ST-elevation myocardial infarction but without angiographic evidence of a coronary event were deemed false positive. In 2012, the referral algorithm was modified to exclude supraventricular tachycardia and left bundle branch block.

RESULTS

There were 155 activations in the early cohort (2010-2012; prior to algorithm modification) and 313 in the late cohort (2012-2015). Algorithm modification resulted in a 42% relative decrease in the rate of IAs (12% vs 7%; P < 0.01) without a significant effect on treatment delay.

CONCLUSIONS

A combination of prehospital automated ST-elevation myocardial infarction diagnosis and "physicianless" CCL activation is safe and effective in improving treatment delay and these results are sustainable over time. The performance of the referral algorithm in terms of IA and false positive is at least on par with systems that ensure real-time human oversight.

Prehospital factors associated with an acute life-threatening condition in non-traumatic chest pain patients - A systematic review

BACKGROUND

Chest pain is a common symptom among patients contacting the emergency medical services (EMS). Risk stratification of these patients is warranted before arrival in hospital, regarding likelihood of an acute life-threatening condition (LTC).

AIM

To identify factors associated with an increased risk of acute LTC among patients who call the EMS due to non-traumatic chest pain.

METHODS

Several databases were searched for relevant articles. Identified articles were quality-assessed using the Scottish Intercollegiate Guidelines Network checklists. Extracted data was analysed using a semi-quantitative synthesis evaluating the level of evidence of each identified factor.

RESULTS

In total, 10 of 1245 identified studies were included. These studies provided strong evidence for an increased risk of an acute LTC with increasing age, male gender, elevated heart rate, low systolic blood pressure and ST elevation or ST depression on a 12-lead ECG. The level of evidence regarding the history of myocardial infarction, angina pectoris or presence of a Q wave or a Left Bundle Branch Block on the ECG was moderate. The evidence was inconclusive regarding dyspnoea, cold sweat/paleness, nausea/vomiting, history of chronic heart failure, smoking, Right Bundle Branch Block or T-inversions on the ECG.

CONCLUSIONS

Factors reflecting age, gender, myocardial ischemia and a compromised cardiovascular system predicted an increased risk of an acute life-threatening condition in the prehospital setting in cases of acute chest pain. These factors may form the basis for prehospital risk stratification in acute chest pain.

Paramedic Recognition of Sepsis in the Prehospital Setting: A Prospective Observational Study

Background. Patients with sepsis benefit from early diagnosis and treatment. Accurate paramedic recognition of sepsis is important to initiate care promptly for patients who arrive by Emergency Medical Services. Methods. Prospective observational study of adult patients (age ≥ 16 years) transported by paramedics to the emergency department (ED) of a Canadian tertiary hospital. Paramedic identification of sepsis was assessed using a novel prehospital sepsis screening tool developed by the study team and compared to blind, independent documentation of ED diagnoses by attending emergency physicians (EPs). Specificity, sensitivity, accuracy, positive and negative predictive value, and likelihood ratios were calculated with 95% confidence intervals. Results. Overall, 629 patients were included in the analysis. Sepsis was identified by paramedics in 170 (27.0%) patients and by EPs in 71 (11.3%) patients. Sensitivity of paramedic sepsis identification compared to EP diagnosis was 73.2% (95% CI 61.4–83.0), while specificity was 78.8% (95% CI 75.2–82.2). The accuracy of paramedic identification of sepsis was 78.2% (492/629, 52 true positive, 440 true negative). Positive and negative predictive values were 30.6% (95% CI 23.8–38.1) and 95.9% (95% CI 93.6–97.5), respectively. Conclusion. Using a novel prehospital sepsis screening tool, paramedic recognition of sepsis had greater specificity than sensitivity with reasonable accuracy.

Innovations in telemedicine for cardiovascular care

Cardiovascular disease is one of the main fields of application for telemedicine, with benefits in almost all areas in the continuum of cardiovascular disease. The greatest impact has been shown in the early diagnosis of cardiovascular disease, in second consultation, between non-cardiologist and cardiologist and between cardiologists, and in follow-up and secondary prevention of cardiovascular disease. At present, the main area of implementation for telemedicine in cardiovascular disease is represented by pre-hospital triage, with telemedicine electrocardiogram in acute myocardial infarction. Significant results have also been achieved in the second opinion consultation of pediatric subjects with congenital cardiovascular disease, home-monitoring and the management of patients affected by chronic heart failure or with an implanted device. However, there is significant room for further improvement in delivering telemedicine assistance even in 'very-remote' populations, such as detainees, patients in developing countries or in underdeveloped areas of developed countries.

Pre-hospital management of patients with chest pain and/or dyspnoea of cardiac origin. A position paper of the Acute Cardiovascular Care Association (ACCA) of the ESC

Chest pain and acute dyspnoea are frequent causes of emergency medical services activation. The pre-hospital management of these conditions is heterogeneous across different regions of the world and Europe, as a consequence of the variety of emergency medical services and absence of specific practical guidelines. This position paper focuses on the practical aspects of the pre-hospital treatment on board and transfer of patients taken in charge by emergency medical services for chest pain and dyspnoea of suspected cardiac aetiology after the initial assessment and diagnostic work-up. The objective of the paper is to provide guidance, based on evidence, where available, or on experts’ opinions, for all emergency medical services’ health providers involved in the pre-hospital management of acute cardiovascular care.

Characteristics of patients with false- ST-segment elevation myocardial infarction diagnoses

BACKGROUND

A subgroup of patients presenting with suspected ST-elevation myocardial infarction (STEMI) have no culprit lesion during coronary angiography (false-positive STEMI). Little is known about patient- and system-related factors that are associated with false-positive STEMI. We evaluated the incidence, correlates, delay, final diagnosis, and outcome of patients with false-positive STEMI.

METHODS

We studied 827 consecutive patients presenting with suspected STEMI between January 2011-September 2012.

RESULTS

A false positive STEMI activation was identified in 68 patients (8.2%). Patients with false-positive STEMI were younger (57 vs 63 year; p=0.020), less often had hypercholesterolemia (19 vs 43%; p=0.001), and had a higher heart rate (82 vs 75 bpm; p=0.014). The association between these factors and false-positive STEMI activation persisted in multivariate analysis. The duration of symptoms to call was longer in false-positive STEMI patients (128 vs 83 min; p=0.030), although this did not reach statistical significance in multivariate analysis. Final diagnosis in patients with false-positive STEMI activation was particularly from unknown origin (41%). There were no significant differences in mortality at 30 days and one year between patients with STEMI and false-positive STEMI.

CONCLUSION

The incidence of false-positive STEMI was 8.2% in patients suspected of STEMI. Patients with false-positive STEMI differ from STEMI patients in certain baseline characteristics and in patient delay. Interestingly, absence of coronary disease did not translate into better clinical outcome.

Telemedicine for cardiovascular disease continuum: A position paper from the Italian Society of Cardiology Working Group on Telecardiology and Informatics

Telemedicine is the provision of health care services, through the use of information and communication technology, in situations where the health care professional and the patient, or 2 health care professionals, are not in the same location. It involves the secure transmission of medical data and information, through text, sound, images, or other forms needed for the prevention, diagnosis, treatment, and follow-up of a patient. First data on implementation of telemedicine for the diagnosis and treatment of acute myocardial infarction date from more than 10 years ago. Telemedicine has a potential broad application to the cardiovascular disease continuum and in many branches of cardiology, at least including heart failure, ischemic heart disease and arrhythmias. Telemedicine might have an important role as part of a strategy for the delivery of effective health care for patients with cardiovascular disease. In this document the Working Group on Telecardiology and Informatics of the Italian Society of Cardiology intends to remark some key-points regarding potential benefit achievable with the implementation of telemedicine support in the continuum of cardiovascular disease.

Electrocardiogram interpretation skills among ambulance nurses

BACKGROUND

To describe ambulance nurses' practical electrocardiogram (ECG) interpretation skills and to measure the correlation between these skills and factors that may impact on the level of knowledge.

METHODS

This study was conducted using a prospective quantitative survey with questionnaires and a knowledge test. A convenience sample collection was conducted among ambulance nurses in three different districts in western Sweden. The knowledge test consisted of nine different ECGs. The score of the ECG test were correlated against the questions in the questionnaire regarding both general ECG interpretation skill and ability to identify acute myocardial infarction using Mann-Whitney U test, Kruskal-Wallis test and Spearman's rank correlation.

RESULTS

On average, the respondents had 54% correct answers on the test and identified 46% of the ECGs indicating acute myocardial infarction. The median total score was 9 of 16 (interquartile range 7-11) and 1 of 3 (IQR 1-2) in infarction points. No correlation between ECG interpretation skill and factors such as education and professional experience was found, except that coronary care unit experience was associated with better results on the ECG test.

CONCLUSIONS

Ambulance nurses have deficiencies in their ECG interpretation skills. This also applies to conditions where the ambulance crew has great potential to improve the outcome of the patient's health, such as myocardial infarction and cardiac arrest. Neither education, extensive experience in ambulance service nor in nursing contributed to an improved result. The only factor of importance for higher ECG interpretation knowledge was prior experience of working in a coronary care unit.

Teaching the interpretation of electrocardiograms: which method is best?

BACKGROUND

Electrocardiogram (ECG) interpretation is poorly performed at undergraduate and post-graduate level. Incorrect ECG interpretation can lead to serious clinical error. Despite the incorporation of computerized ECG interpretation software into modern ECG machines, the sensitivity and specificity of current technology remain poor, emphasizing the on-going need for doctors to perform ECG interpretation accurately.

PURPOSE

This is the first review in this important area and aims to critically evaluate the current literature in relation to the optimal format and method of teaching ECG interpretation at undergraduate and postgraduate level.

CONCLUSIONS

No single method or format of teaching is most effective in delivering ECG interpretation skills; however, self-directed learning appears to be associated with poorer interpretation competence. Summative in preference to formative assessment is associated with improved interpretation competence. Web-based learning offers a promising modern approach to learning ECG interpretation, though caution must be exercised in accessing user-uploaded content to supplement learning.

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

OBJECTIVE

To 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.

METHODS

Population-based linked cohort study of a national myocardial infarction registry.

RESULTS

288 990 patients were admitted to hospitals via emergency medical services (EMS) between 1 January 2005 and 31 December 2009. PHECG use increased overall (51% vs 64%, adjusted OR (aOR) 2.17, 95% CI 2.12 to 2.22), and in STEMI (64% vs 79%, aOR 2.34, 95% CI 2.25 to 2.44). Patients who received PHECG were younger (71 years vs 74 years, P<0.0001); and less likely to be female (33.1% vs 40.3%, OR 0.87, 95% CI 0.86 to 0.89), or to have comorbidities than those who did not. For STEMI, reperfusion was more frequent in those having PHECG (83.5% vs 74.4%, p<0.0001). PHECG was associated with more primary percutaneous coronary intervention patients achieving call-to-balloon time <90 min (27.9% vs 21.4%, aOR 1.38, 95% CI 1.24 to 1.54) and more patients who received fibrinolytic therapy achieving door-to-needle time <30 min (90.6% vs 83.7%, aOR 2.13, 95% CI 1.91 to 2.38). Patients with PHECG exhibited significantly lower 30-day mortality rates than those who did not (7.4% vs 8.2%, aOR 0.94, 95% CI 0.91 to 0.96).

CONCLUSIONS

Findings from this national MI registry demonstrate a survival advantage in STEMI and non-STEMI patients when PHECG was used.

Performance of a new "physician-less" automated system of prehospital ST-segment elevation myocardial infarction diagnosis and catheterization laboratory activation

The door-to-balloon times frequently exceed the recommended delay. We therefore evaluated the performance of a novel "physician-less" cardiac catheterization laboratory (CCL) activation system relying on the automated electrocardiographic diagnosis alone. From January 2010 to 2012, first responders performed electrocardiograms in the field for all patients with a complaint of chest pain or dyspnea. An automated machine diagnosis of "acute myocardial infarction" resulted in immediate CCL activation and direct transfer without human reinterpretation or transmission of the electrocardiogram. Any activation resulting from a nondiagnostic ECG (no ST-segment elevation) was deemed inappropriate and classified as resulting from either human or machine error. Of 155 activations, 136 (88%) were electrocardiographically appropriate. Of these, 128 patients had a final diagnosis of ST-segment elevation myocardial infarction. A door-to-balloon time of <90 minutes was achieved in 99%, the procedural success was high (94%), and the overall mortality was low (3%). Of the electrocardiographically appropriate activations, 8 (5%) were false-positive results. The remaining 19 activations (12%) were inappropriate. Compared with the electrocardiographically appropriate activations, those with inappropriate activations had significantly greater rates of hypertension (p = 0.0070) and known coronary artery disease (p = 0.0008) and higher presenting heart rates (p <0.0001). The causes for inappropriate activation were approximately evenly split between human and machine error. In conclusion, a combination of prehospital automated ST-segment elevation myocardial infarction diagnosis and "physician-less" CCL activation was safe and effective in ensuring target door-to-balloon times in virtually all patients and resulted in an acceptable rate of inappropriate CCL activation.