Accuracy Of ECG Interpretation Research Articles

Abstract 12915: Eye Tracking in the ECG: Exploring the Visual Behavior Patterns of Medical Students

Introduction: While a universal aspect of medical education, there are few validated teaching methods for ECG interpretation. Eye tracking technology applied to study visual patterns during ECG interpretation suggest that top performers localize the critical leads for diagnosis more effectively. No study, however, has analyzed visual behavior occurring within critical leads. Research Question: How does visual behavior of medical students within critical leads correlate with accuracy of ECG interpretation? Aims: We aimed to characterize the visual behavior of medical students interpreting ECGs to help inform future educational methods. Methods: 36 fourth-year students from one medical school completed 9 cases while visual behavior was tracked via a Tobii Pro Nano eyetracker and analyzed with iMotions software. Cases included a vignette and 12-lead ECG followed by viewing up to three critical leads. We included five morphologic abnormalities (e.g. LBBB) and four arrhythmias (e.g. AVNRT). Accuracy was assessed via multiple choice questions after viewing the 12-lead ECG alone and again after viewing critical leads. Dwell time, the time spent focused on a given lead, and fixation count, the number of discrete focuses > 60 ms, were analyzed via Mann-Whitney U testing. Data: 36.1% of students correctly interpreted all ECGs with morphologic abnormalities compared to 16.7% for arrhythmias. Within critical leads, there was a significant difference in average dwell time (2.62 vs 5.21 seconds (s), p <0.001) and fixation count (9.59 vs 16.5, p<0.001) between morphologic versus arrhythmia ECGs. Higher performers had decreased average dwell time and fixation count in critical leads compared to inaccurate interpreters for morphologic (2.39 vs 3.39 s, p=0.003; 8.92 vs 11.9 fixations, p<0.01) and arrhythmia (4.32 vs 7.04 s, p<0.01; 13.4 vs 22.7 fixations, p<0.01), respectively. Conclusion: Our study demonstrates that learners spend less focused time interpreting morphologic as compared to arrhythmia ECGs. Further, dwell times and fixation counts were lower amongst higher performers. Measurement of discrete visual behavior may provide a novel way to assess students’ pattern recognition skills and interpretation competency while also enhancing ECG didactic methods.

Lewis Lead: Reveal the Hidden P Wave

Background. The Lewis lead configuration can help to detect atrial activity and its relationship to ventricular activity, so diagnosis can be achieved more accurately. With Lewis lead ECG, it will make easier to make a diagnosis, especially in identifying electrical activity in the atrium.
 Case Illustration. Case 1. A 61-year-old male with decreased consciousness et causa metabolic. From a standard 12-lead ECG, the P waves are difficult to identify, and at first glance it looks like atrial fibrillation. From the Lewis ECG in lead I, it appears that the QRS wave is always preceded by a P wave, with different morphologies (more than 3 forms), that showed as multifocal atrial tachycardia (MAT) with a heart rate of 120 beats / minute. Case 2. The 58-year-old male patient complained of typical ischemic chest pain and palpitations. A standard 12 lead ECG examination revealed a rhythmic tachycardia with a wide QRS wave at a rate of 210 beats / minute. From the Lewis ECG in lead I, we can see that the P waves that appear are not always followed by QRS. Thus, it can be seen that the AV dissociation is a VT so that VT management can be done immediately. Case 3. A 65-year-old male patient diagnosed with grade 5 CKD on dialysis. From a standard 12 lead ECG examination, a wide QRS wave with a P wave is obtained which is sometimes seen behind the QRS wave, making the diagnosis difficult to establish. From the Lewis ECG in lead I, it appears that the P wave always appears at the end of the QRS wave, so it can be seen that the rhythm from the ECG is derived from accelerated idioventricular rhythm with ventriculoatrial conduction.
 Conclusion. The accuracy of ECG interpretation is needed to determine the next treatment for the patient. Through the ECG examination with the Lewis lead method, the cardiac electrical activity will be more visible, so it will be very helpful in the interpretation of the ECG in cases that are not clear on the standard 12 lead ECG examination.

IMPROVING ECG DIAGNOSTIC ACCURACY IN EMERGENCY MEDICAL SERVICES PERSONNEL

Accuracy of ECG interpretation is important for identification of ST-elevation myocardial infarctions (STEMI) by Emergency Medical Service (EMS) personnel who recognize STEMIs in the field and activate the coronary catheterization lab (CCL). Based on our previous research there is improvement in diagnostic accuracy of STEMIs for healthcare providers that read an average of >20 ECGs per week. This study evaluated the effectiveness of online ECG education modules on improving ECG diagnostic accuracy. EMS personnel received 25 ECGs per week to interpret via an online program. Evaluation for effect on improvement in diagnostic accuracy was assessed via completion of an ECG evaluation package before and after the intervention. Data was collected regarding job satisfaction to determine if the educational initiative had any significant impacts. A total of 64 participants completed the education modules and accompanying evaluation packages. Overall, there was a significant improvement in ECG diagnostic accuracy from 51 to 62% (95% CI 7.7-13.2, p < 0.0001). Specifically there was statistically significant improvement in the diagnosis of STEMI (8.5% (95% CI 4.9-12.3), p < 0.003) and supraventricular tachycardia (39% (95% CI 17.2-60.8, p < 0.008), with the trend toward improvement in all other diagnoses. These effects were sustained out to the three-month follow up period (9.6% (95% CI 6.4-12.7), p= < 0.0001). Improvement was seen regardless of EMS personnel’s employment experience and training. There was no significant impact on job satisfaction. ECG exposure remains an important factor in improving the accuracy of ECG diagnosis in EMS personnel. Online education modules provide an easily accessible way of improving ECG interpretation with the opportunity for positive downstream effects on patient outcomes and resource utilization.

Effectiveness of an emergency nurse practitioner service for adults presenting to rural hospitals with chest pain: protocol for a multicentre, longitudinal nested cohort study

IntroductionChest pain is common in emergency department (ED) patients and represents a considerable burden for rural health services. Health services reforms to improve access to care need appropriately skilled and...

Diagnostic accuracy of ST-segment elevation myocardial infarction by various healthcare providers

BackgroundThis study aimed to compare the accuracy of ECG interpretation for diagnosis of STEMI by different groups of healthcare professionals involved in the STEMI program at our institution. MethodsWe selected 21 ECGs from patients with typical symptoms of MI that were diagnosed with STEMI, and 10 ECGs of STEMI mimics. STEMI mimic ECGs were repeated in the package with a story of typical and atypical chest pain. ECGs were interpreted to diagnose STEMI and identify need for initiation of the cardiac catheterization lab (CCL). Participants identified confidence in STEMI recognition, and average number of ECGs read per week. ResultsA total of 64 participants completed the study package. Cardiologists were more likely to provide correct interpretation compared to other groups. False positive diagnoses were more likely made by paramedics when compared to cardiologists (p<0.01). There was a positive correlation between increased exposure to ECGs and accurate STEMI diagnosis (r=0.482, p<0.001). A threshold of ≥20 ECGs read per week showed a statistically significant improvement in accuracy (p<0.001). Self-reported confidence correlated positively with accuracy (r=0.402, p=<0.001). Changing the ECG narrative of the STEMI mimic ECGs had a significant effect on interpretation between groups (p=0.043). ConclusionsOur study showed that healthcare profession and number of ECGs reviewed per week are predictive of the accuracy of ECG interpretation of STEMI. Cardiologists are the most accurate diagnosticians, and are the least likely to falsely activate the CCL. Weekly exposure of ≥20 ECGs may improve diagnostic accuracy regardless of underlying experience.

Standardised criteria improve accuracy of ECG interpretation in competitive athletes: a randomised controlled trial

BackgroundScreening to prevent sudden cardiac death remains a contentious topic in sport and exercise medicine. The aim of this study was to assess whether the use of a standardised criteria...

Accuracy of ECG interpretation in competitive athletes: the impact of using standardised ECG criteria

BackgroundInterpretation of ECGs in athletes is complicated by physiological changes related to training. The purpose of this study was to determine the accuracy of ECG interpretation in athletes among different...

Inaccuracy of ECG Interpretations Reported to the Poison Center

The ECG is an essential tool in the care of poisoned patients. This study is designed to investigate the accuracy of ECG interpretation reported to a poison center. In this prospective study, all cases in which both an electronically faxed copy of the ECG and the caller's interpretation of the ECG were available were eligible for inclusion. ECG interpretation of callers was compared with that of a blinded electrophysiologist. In cases of disagreement, a Delphi panel of toxicologists decided whether the differences were clinically significant or would have changed recommendations. Two hundred cases were included, with complete agreement in 78. In 23 cases, the sole difference was nonspecific ST-T-wave changes, which were believed insignificant and classified as agreement for a total of 101. The Delphi panel reviewed the remaining 99. In 42 cases, the differences in ECG interpretations were thought to be clinically significant; 37 of these would have resulted in a change in management recommendations. Forty-five cases were thought not likely to be clinically significant and would not have resulted in a recommendation change. Twelve cases were thought not clinically significant but would still have resulted in a change in recommendations. Initial interpretation of the ECG reported by callers to the poison center is frequently inaccurate. In this study, the misinterpretation was clinically significant or would have resulted in a change in management recommendations in approximately one quarter of all calls.

Accuracy of ECG interpretation in primary care was limited for detecting atrial fibrillation

Accuracy of ECG interpretation in primary care was limited for detecting atrial fibrillation

Accuracy of ECG Interpretation in the Pediatric Emergency Department

We assess accuracy of ECG interpretation and indications for obtaining ECGs and develop a clinical classification system of ECG abnormalities. Prospectively acquired ECG data on patients 0 to 21 years of age and presenting to our pediatric emergency department (ED) were obtained. Clinical indications were documented. The initial ECG interpretation (pediatric ED attending physician) was compared with the criterion standard (pediatric cardiologist). A blinded cardiology panel reviewed discrepancies, and a final concordance rate was determined. An ECG abnormality classification system was developed and used to categorize these abnormal ECGs. One thousand six hundred fifty-three ECGs from 1,501 patients, aged 2 days to 21 years (median 10.0 years), were obtained during 3.5 years. Fifty-one percent were male patients. ECG indications included chest pain (21%), seizure or syncope (18%), arrhythmias (17%), apparent life-threatening event or respiratory symptoms (16%), ingestions (10%), cardiac abnormality (10%), and miscellaneous (8%). From 1,631 ECGs, 1,160 (71%) were normal (class 0), 259 (16%) were minimally abnormal (class I), 174 (11%) were moderately abnormal (class II), and 38 (2%) were severely abnormal (class III). Kendall's tau-b test showed concordance of 0.73 (95% confidence interval 0.70 to 0.77) between pediatric ED and cardiology interpretation. The sensitivity of pediatric ED interpretation was 75%, and the specificity was 98.5%. The positive predictive value of pediatric ED interpretation was 88.3%, and the negative predictive value was 96.3%. We conclude that, overall, a high rate of concordance exists between the pediatric emergency physician's and the cardiologist's ECG interpretation. The majority of discordant ECGs are not clinically significant. However, among the clinically significant ECGs, there is a higher rate of discordance. These data suggest that review of pediatric ECGs by pediatric cardiologists may significantly reduce underdetection of clinically important ECG findings in children.

Influence of mobile phones on accuracy of ECG interpretation algorithm in automated external defibrillator

Background: Automated External Defibrillators (AED) are a recommended tool for out-of-hospital emergency medical services. Mobile phones (GSM) are a potential source of electromagnetic interference which may cause failure of ECG interpretation and subsequent inappropriate action of AED's. Methods: We evaluated the influence of 900 MHz GSM phones on the accuracy of automatic ECG interpretation with a GSM Mobile Station Tester with adjustable power and mode of transmission (Hewlett-Packard HP5515A), GSM phones (Alcatel, Ericsson, Nokia, Panasonic), ECG simulator (Metron) and four AEDs (Fore Runner—Hewlett-Packard, Heartstart 3000—Laerdal, Cardio-Aid 100—Artema, Heartstream XLT—Agilent). The protocol included 18 different ECG patterns, different ECG voltages, and different power and mode of transmission. Results: The first stage of the protocol included minimal power of signal transmitted from GSM Mobile Station Tester and maximum power of GSM phone's signal—hence maximal potential interference to AED. The protocol was based on close direct contact between the GSM phone and the AED device. Regardless of the ECG pattern, with both 0.5 and 1.0 mV ECG voltage, and the GSM phone placed on various parts of AED device or at the patient cable, no failure of AED algorithm occurred. No detectable noise was seen at AED's ECG display. Conclusion: AEDs seems to be well protected against clinically significant failure caused by noise from 900 MHz GSM phones.

Noonan syndrome.

<h3>Introduction</h3> County Donegal has traditionally been isolated as a result of its geographical remoteness from 24/7 Primary Percutaneous Intervention (PPCI) enabled centres in the Republic of Ireland. The National Acute Coronary Syndrome (ACS) programme is designed to increase access to PPCI for patients with ST Elevation Myocardial Infarction (STEMI). A cross-border initiative between the SAOLTA Hospitals, HSE, Republic of Ireland and the Western Health and Social Care Trust in Northern Ireland commenced on 5th May 2016 to provide PPCI for Donegal. We sought to evaluate the initial effectiveness of this unique Cross border PPCI pathway. <h3>Methods</h3> ECG’s from Donegal patients suspected of having a STEMI were transmitted from the National Ambulance Service (NAS) or Letterkenny University Hospital (LUH) ER to Altnagelvin Hospital PPCI service. All data were recorded for continuous audit purposes to assess performance indicators, ECG interpretation and the number of referrals made to the PPCI activator in Altnagelvin. All patients who had an ECG transmitted to Altnagelvin PPCI centre from May 2016 to March 2017 were included. <h3>Results</h3> 139 patients were referred with a suspected STEMI to the Cross Border PPCI pathway with 88/139 patients (63%) referred from the National Ambulance Service (NAS); the rest referred from LUH ER. 95/139 (68%) patients were turned down. Only 44/139 patients were accepted for PPCI with a false activation rate of 32%. Only 30/139 patients actually had a final diagnosis of STEMI. The mean time from STEMI diagnosis on ECG to reestablishing flow in the culprit artery was 117.8 minutes within guidelines. No complications occurred during transfer and 89% were repatriated within 24 hrs. All 95 patients that were turned down were deemed appropriate with only 10/95 (10.5%) actually requiring PCI prior to discharge. <h3>Conclusion</h3> Initial audit of this unique Cross Border PPCI pathway suggests that it is working effectively. The high referral rate and high rate of turn-downs suggest that diagnostic accuracy of ECG interpretation may need to be evaluated. The high rate of false activations is notable and also requires further investigation. The early success of this unique Cross border service is very encouraging when considering the geographical remoteness of Donegal. Work will continue to further improve this vital service for the people of Donegal.

Computer analysis of the electrocardiogram: Evaluation of experience in a hospital heart station

C ardiologists and administrators, concerned with the increasing volume of hospital electrocardiograms (ECG’s), are considering automation as a means of saving money and manpower. The initial cost for computer systems for ECG processing is high and prospective purchasers should fully understand the limitations as well as the capabilities of these systems for clinical use. In a collaborative study with the Medical Systems Development Laboratory of the United States Public Health Service, the Heart Station of the George Washington University Hospital used computer-derived ECG interpretations as part of its routine ECG processing from 1964 to 1968. Computer processing7 was performed by the Medical Systems Development Laborat0ry.l Members of the Heart Station staff assisted in the development of diagnostic criteria and in the evaluation of the programe2 This report describes the operation of the computer system in our institution over a 12 month period, presents an analysis of the system with emphasis on the accuracy of ECG interpretation, and evaluates computer analysis of the ECG for use in hospital practice.