Accuracy in ECG lead placement among technicians, nurses, general physicians and cardiologists

Performing Accurate Standard 12 Lead ECGs on patients with Burns to the Chest

The use of the electrocardiogram (ECG) in critical care settings is a long-established cardiovascular monitoring tool. The effectiveness of the routine 12-lead ECG relies on accurate lead placement that is consistent and replicable. Improper lead placement may display erroneous ECG patterns and affect patient management decisions.1,2 In the setting of an acute injury, such as a torso burn to the ventral surface, accurate lead placement may be compromised or impossible. The regional burn center, which is part of our organization, sees approximately 500 patients per year. Of those patients, burns to the chest accounted for 21% of admissions during 2020 and 2021. This significant fraction of burn injury patients requires modification of our standard approach to provide an accurate ECG. Baseline ECGs are routinely acquired on the burn unit per protocol and for monitoring of patient response to numerous pharmaceutical therapies.

Myocardial Infarction Simulated From Improper Telemetry (MISFIT): An Autobiographical Case Report

An electrocardiogram, used to not only assess the rate and rhythm of the heart but also to evaluate for injury to the heart, is performed by attaching 12 leads to the patient's body. A myocardial infarction can be mimicked by the misplacement of the leads. A 58-year-old man with long-distance running-associated bradycardia developed postoperative atrial fibrillation with a rapid ventricular response. He converted to normal sinus rhythm after a single oral dose of 30 milligrams of diltiazem; however, the automated reading of the electrocardiogram performed in the hospital showed new changes suggestive of a postero-lateral myocardial infarction, including Q waves in leads I and aVL, as well as early precordial R wave progression with R waves and positive T waves in V2 and V3, and a dominant R wave (R wave to S wave ratio greater than one) in V2. A cardiac work-up was entirely normal: serial troponin levels, thyroid stimulating hormone, echocardiogram, computerized tomography of the chest, and Doppler studies of the extremities. Lead misplacement during the electrocardiogram was suspected during the subsequent evaluation by an astute cardiologist; the findings were diagnostic for a left arm to right arm limb lead reversal. All the changes in myocardial infarction were absent when the electrocardiogram was repeated in the office. Misplacement of leads during an electrocardiogram is not a rare event; therefore, the clinician needs to consider the possibility of improper placement of the leads when evaluating an electrocardiogram. Indeed, emotional distress, additional diagnostic procedures, and potentially harmful procedures may be experienced by the patient from incorrect diagnoses based on electrode misplacement during an electrocardiogram; in addition, there are often increased costs to the patient and the healthcare system. Therefore, in the setting of an incorrect diagnosis attributed to lead misplacement during the performance of an electrocardiogram, the acronym MISFIT (which uses the first letters of the words "myocardial infarction simulated from improper telemetry") has been introduced. In conclusion, it is important to emphasize that a MISFIT is characterized by an electrocardiogram 'mis'diagnosis of a myocardial infarction that does not 'fit' with the clinical scenario.

Using the Apple Watch to Record Multiple-Lead Electrocardiograms in Detecting Myocardial Infarction: Where Are We Now?

Although the outcome after myocardial infarction depends on the time to treatment, a delay between symptom onset and treatment is common. Apple Watch, a popular wearable device, provides the ability to perform an electrocardiogram. We review the progress made in using the Apple Watch to record multiple electrocardiogram leads for diagnosing myocardial infarction. Although the data are encouraging, many limitations remain, and more research is needed. Nevertheless, the Apple Watch could eventually serve as a self-check tool for patients who have chest pains or other symptoms of myocardial infarction, thus substantially decreasing the time to treatment and improving the outcome after myocardial infarction.

Effects of Electrocardiographic Monitoring Education on Nurses' Confidence and Psychological Stress: An Online Cross-Sectional Survey in Japan

We aimed to investigate the association between nurses’ electrocardiographic (ECG) monitoring education and their confidence and psychological stress regarding ECG monitoring. In 2019, a web-based cross-sectional study was conducted among Japanese nurses. A multivariable logistic regression analysis was performed to evaluate the effects of education on nurses’ confidence and psychological stress regarding ECG monitoring. In total, 1652 nurses were included in the study. Factors significantly associated with nurses’ confidence were post-graduate education experience (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.6–3.6), ≥11 post-graduate years (OR, 2.2; 95% CI, 1.5–3.1), male gender (OR, 4.4; 95% CI, 2.9–6.6), ≥5 helpful experiences with ECG monitoring (OR, 10.7; 95% CI, 6.0–19.1), work experience in an intensive care unit (OR, 2.3; 95% CI, 1.5–3.7), and work experience in a cardiology department (OR, 1.7; 95% CI, 1.2–2.4). Factors significantly associated with nurses’ psychological stress were male gender (OR, 1.9; 95% CI, 1.2–2.9), ≥5 helpful experiences with ECG monitoring (OR, 1.9; 95% CI, 1.2–2.9), and work experience in an emergency room (OR, 2.4; 95% CI, 1.3–4.8). These results suggest that nurses’ post-graduate ECG monitoring education enhanced their confidence, but did not reduce psychological stress regarding ECG monitoring.

Nurses' competency in electrocardiogram interpretation in acute care settings: A systematic review

AIMS

Identify and synthesize evidence of nurses' competency in electrocardiogram interpretation in acute care settings.

DESIGN

Systematic mixed studies review.

DATA SOURCES

Cumulative Index to Nursing and Allied Health Literature, Medline, Scopus and Cochrane were searched in April 2021.

REVIEW METHODS

Data were selected using the updated Preferred Reporting Items for Systematic Reviews and Meta-Analysis framework. A data-based convergent synthesis design using qualitative content analysis was adopted. Quality appraisal was undertaken using validated tools appropriate to study designs of the included papers.

RESULTS

Forty-three papers were included in this review. Skills and attitudes were not commonly assessed, as most studies referred to 'competency' in the context of nurses' knowledge in electrocardiogram interpretation. Nurses' knowledge levels in this important nursing role varied notably, which could be partly due to a range of assessment tools being used. Several factors were found to influence nurses' competency in electrocardiogram interpretation across the included studies from individual, professional and organizational perspectives.

CONCLUSION

The definition of 'competency' was inconsistent, and nurses' competency in electrocardiogram interpretation varied from low to high. Nurses identified a lack of regular training and insufficient exposure in electrocardiogram interpretation. Hence, regular, standard training and education are recommended. Also, more research is needed to develop a standardized and comprehensive electrocardiogram interpretation tool, thereby allowing educators to safely assess nurses' competency.

IMPACT

This review addressed questions related to nurses' competency in electrocardiogram interpretation. The findings highlight varying competency levels and assessment methods. Nurses reported a lack of knowledge and confidence in interpreting electrocardiograms. There is an urgent need to explore opportunities to promote and maintain nurses' competency in electrocardiogram interpretation.

Accuracy of ECG chest electrode placements by paramedics: an observational study

Background:

The use of the 12-lead electrocardiogram (ECG) is common in sophisticated pre-hospital emergency medical services but its value depends upon accurate placement of the ECG electrodes. Several studies have shown widespread variation in the placement of chest electrodes by other health professionals but no studies have addressed the accuracy of paramedics. The main objective of this study was to ascertain the accuracy of the chest lead placements by registered paramedics.

Methods:

Registered paramedics who attended the Emergency Services Show in Birmingham in September 2018 were invited to participate in this observational study. Participants were asked to place the chest electrodes on a male model in accordance with their current practice. Correct positioning was determined against the Society for Cardiological Science and Technology’s 2017 clinical guidelines for recording a standard 12-lead ECG, with a tolerance of 19 mm being deemed acceptable based upon previous studies.

Results:

Fifty-two eligible participants completed the study. Measurement of electrode placement in the vertical and horizontal planes showed a high level of inaccuracy, with 3/52 (5.8%) participants able to accurately place all chest electrodes. In leads V₁–V₃, the majority of incorrect placements were related to vertical displacement, with most participants able to identify the correct horizontal position. In V₄, the tendency was to place the electrode too low and to the left of the pre-determined position, while V₅ tended to be below the expected positioning but in the correct horizontal alignment. There was a less defined pattern of error in V₆, although vertical displacement was more likely than horizontal displacement.

Conclusions:

Our study identified a high level of variation in the placement of chest ECG electrodes, which could alter the morphology of the ECG. Correct placement of V₁ improved placement of other electrodes. Improved initial and refresher training should focus on identification of landmarks and correct placement of V₁.

Reliable Deep Learning-Based Detection of Misplaced Chest Electrodes During Electrocardiogram Recording: Algorithm Development and Validation

Background

A 12-lead electrocardiogram (ECG) is the most commonly used method to diagnose patients with cardiovascular diseases. However, there are a number of possible misinterpretations of the ECG that can be caused by several different factors, such as the misplacement of chest electrodes.

Objective

The aim of this study is to build advanced algorithms to detect precordial (chest) electrode misplacement.

Methods

In this study, we used traditional machine learning (ML) and deep learning (DL) to autodetect the misplacement of electrodes V1 and V2 using features from the resultant ECG. The algorithms were trained using data extracted from high-resolution body surface potential maps of patients who were diagnosed with myocardial infarction, diagnosed with left ventricular hypertrophy, or a normal ECG.

Results

DL achieved the highest accuracy in this study for detecting V1 and V2 electrode misplacement, with an accuracy of 93.0% (95% CI 91.46-94.53) for misplacement in the second intercostal space. The performance of DL in the second intercostal space was benchmarked with physicians (n=11 and age 47.3 years, SD 15.5) who were experienced in reading ECGs (mean number of ECGs read in the past year 436.54, SD 397.9). Physicians were poor at recognizing chest electrode misplacement on the ECG and achieved a mean accuracy of 60% (95% CI 56.09-63.90), which was significantly poorer than that of DL (P<.001).

Conclusions

DL provides the best performance for detecting chest electrode misplacement when compared with the ability of experienced physicians. DL and ML could be used to help flag ECGs that have been incorrectly recorded and flag that the data may be flawed, which could reduce the number of erroneous diagnoses.

P-Wave Terminal Force in Dogs With Myxomatous Mitral Valve Disease

P-wave terminal force (PTF) is accepted as an electrocardiographic criteria to assess left atrial abnormalities in humans. In this study, the applicability of PTF in dogs with myxomatous mitral valve disease (MMVD) was evaluated, and compared its ability to identify left atrial dilatation with 4 other P-wave derived parameters. Seventy-four dogs with echocardiographically diagnosed MMVD were recruited for this prospective cross-sectional study. Also, 47 healthy dogs were included to serve as controls. All dogs underwent physical, electrocardiographic and standard echocardiographic examinations prior to enrollment. Electrocardiographic measurements were obtained from simultaneous recordings at three different locations for precordial lead V₁. PTF was defined as the deflection following the second half of the P-wave, and was best documented at the first and third right intercostal spaces. In those locations, the P-wave was negative and P-wave terminal force was recognized as a positive undulation in baseline following P-wave. P-wave terminal force and P-wave duration measured from recordings obtained at either the first or third right intercostal spaces had poor to weak correlations (P < .05) with echocardiographic surrogates of cardiac remodeling and congestion. In dogs with MMVD, only P-wave duration and P-wave area distinguished normal and dilated left atria (P < .05). In conclusion, PTF had positive polarity and was best recorded when precordial lead V₁ electrode was placed at the most cranial right intercostal locations. PTF failed to reliably identify left atrial enlargement in dogs with MMVD.

Hybrid Decision Support to Monitor Atrial Fibrillation for Stroke Prevention

In this paper, we discuss hybrid decision support to monitor atrial fibrillation for stroke prevention. Hybrid decision support takes the form of human experts and machine algorithms working cooperatively on a diagnosis. The link to stroke prevention comes from the fact that patients with Atrial Fibrillation (AF) have a fivefold increased stroke risk. Early diagnosis, which leads to adequate AF treatment, can decrease the stroke risk by 66% and thereby prevent stroke. The monitoring service is based on Heart Rate (HR) measurements. The resulting signals are communicated and stored with Internet of Things (IoT) technology. A Deep Learning (DL) algorithm automatically estimates the AF probability. Based on this technology, we can offer four distinct services to healthcare providers: (1) universal access to patient data; (2) automated AF detection and alarm; (3) physician support; and (4) feedback channels. These four services create an environment where physicians can work symbiotically with machine algorithms to establish and communicate a high quality AF diagnosis.

The Reconstruction of a 12-Lead Electrocardiogram from a Reduced Lead Set Using a Focus Time-Delay Neural Network

BACKGROUND

The 12-lead electrocardiogram (ECG) is the gold-standard ECG method used by cardiologists. However, accurate electrode placement is difficult and time consuming, and can lead to incorrect interpretation.

OBJECTIVES

The objective of this study was to accurately reconstruct a full 12-lead ECG from a reduced lead set.

METHODS

Five-electrode placement was used to generate leads I, II, III, aVL, aVR, aVF and V2. These seven leads served as inputs to the focus time-delay neural network (FTDNN) which derived the remaining five precordial leads (V1, V3-V6). An online archived medical database containing 549 cases of ECG recordings was used to train, validate and test the FTDNN.

RESULTS

After removing outliers, the reconstructed leads exhibited correlation values of between 0.8609 and 0.9678 as well as low root mean square error values of between 123 μV and 245 μV across all cases, for both healthy controls and cardiovascular disease subgroups except the bundle branch block disease subgroup. The results of the FTDNN method compared favourably to those of prior lead reconstruction methods.

CONCLUSIONS

A standard 12-lead ECG was successfully reconstructed with high quantitative correlations from a reduced lead set using only five electrodes, of which four were placed on the limbs. Less reliance on precordial leads will aid in the reduction of electrode placement errors, ultimately improving ECG lead accuracy and reduce the number of cases that are incorrectly diagnosed.

Wearable 3-Lead Electrocardiogram Placement Model for Fleet Sizing of Medical Devices

BACKGROUND: Electrocardiography (ECG) provides valuable information on astronaut physiological and psychological health. ECG monitoring has been conducted during crewed missions since the beginning of human spaceflight and will continue during astronauts upcoming long-duration exploration missions (LDEMs) in support of automated health monitoring systems. ECG monitoring is traditionally performed in clinical environments with single-use, adhesive electrodes in a 3, 6, or 12-lead configuration placed by a trained clinician. In the space exploration environment, astronauts self-place electrodes without professional assistance. Wearable ECG systems are an attractive option for automated health monitoring, but electrode placement has not been quantified to a high enough degree to avoid artifacts within the data due to position changes. This variability presents challenges for physician-limited, autonomous health monitoring, so quantifying electrode placement is key in the development of reliable, wearable ECG monitoring systems.METHODS: We present a method of quantifying electrode placement for 3-lead, chest-mounted ECG using easy-to-measure, two-dimensional chest measurements.RESULTS: We find that male and female dimensions require different electrode positioning computations, but there is overlap in positioning between men and women. The distribution of electrodes vertical positions is wider than their horizontal positions.DISCUSSION: These results can be translated directly to ECG wearable design for the individual and for the size range and adjustability required for the astronaut fleet. Implementation of this method will improve the reliability in placement and fit of future wearables, increasing comfort and usability of these systems and subsequently augmenting autonomous health monitoring capabilities for exploration medicine.Arquilla K, Leary S, Webb AK, Anderson AP. Wearable 3-lead electrocardiogram placement model for fleet sizing of medical devices. Aerosp Med Hum Perform. 2020; 91(11):868875.

Big Data and Artificial Intelligence: Opportunities and Threats in Electrophysiology

The combination of big data and artificial intelligence (AI) is having an increasing impact on the field of electrophysiology. Algorithms are created to improve the automated diagnosis of clinical ECGs or ambulatory rhythm devices. Furthermore, the use of AI during invasive electrophysiological studies or combining several diagnostic modalities into AI algorithms to aid diagnostics are being investigated. However, the clinical performance and applicability of created algorithms are yet unknown. In this narrative review, opportunities and threats of AI in the field of electrophysiology are described, mainly focusing on ECGs. Current opportunities are discussed with their potential clinical benefits as well as the challenges. Challenges in data acquisition, model performance, (external) validity, clinical implementation, algorithm interpretation as well as the ethical aspects of AI research are discussed. This article aims to guide clinicians in the evaluation of new AI applications for electrophysiology before their clinical implementation.

Feasibility of CardioSecur®, a Mobile 4-Electrode/22-Lead ECG Device, in the Prehospital Emergency Setting

Background: This study explores the application of CardioSecur® (CS-ECG), a hand-held 4-electrode/22-lead ECG-device, in comparison with conventional 12-lead electrocardiogram (c12L-ECG) in patients with acute chest pain in the prehospital emergency setting. Methods: CS-ECG systems were provided for two physician-staffed emergency ambulances and parallel recordings of c12L-ECG and CS-ECG were obtained from all patients with acute chest pain. Treating emergency physicians were asked to evaluate the CS-ECG system with a standardized questionnaire. Following study completion, acquired ECGs were analyzed separately by two independent cardiologists blinded to all other medical records. Results: Over a period of 20 months a total of 203 patients were included in our study. According to a standardized questionnaire, 79% of emergency medical professionals preferred application of CS-ECG, with 87% of teams judging CS-ECG to be beneficial for patients. Morover, 79% of physicians reported a reduction in time to definitive diagnosis with implementation of CS-ECG. The majority of professional users attested user-friendliness and feasibility of CS-ECG in terms of easy general handling (94%), application (93%), and placement of electrodes (98%). During prehospital triage, both c12L-ECG and CS-ECG correctly identified 31 (91%) patients with ST-elevation myocardial infarction (STEMI). Conclusion: In this first pilot study, implementation of the CardioSecur®-ECG system in the prehospital emergency setting demonstrated feasibility and user-friendliness so that emergency teams generally preferred CS-ECG to c12L-ECG. Diagnostic yield of CS-ECG was similar to c12L-ECG recordings.

Evaluation of relationships between results of electrocardiography and echocardiography in 341 chimpanzees (Pan troglodytes)

OBJECTIVE

To examine potential relationships between ECG characteristics and echocardiographic measures of cardiac structure in chimpanzees (Pan troglodytes).

ANIMALS

341 chimpanzees (175 males and 166 females) from 5 sanctuaries and 2 zoological collections.

PROCEDURES

Chimpanzees were anesthetized for routine health examinations between May 2011 and July 2017 as part of the International Primate Heart Project and, during the same anesthetic events, underwent 12-lead ECG and transthoracic echocardiographic assessments. Relationships between results for ECG and those for echocardiographic measures of atrial areas, left ventricular internal diameter in diastole (LVIDd), and mean left ventricular wall thicknesses (MLVWT) were assessed with correlational analysis, then multiple linear regression analyses were used to create hierarchical models to predict cardiac structure from ECG findings.

RESULTS

Findings indicated correlations (r = -0.231 to 0.310) between results for ECG variables and echocardiographic measures. The duration and amplitude of P waves in lead II had the strongest correlations with atrial areas. The Sokolow-Lyon criteria, QRS-complex duration, and R-wave amplitude in leads V₆ and II had the strongest correlations with MLVWT, whereas the Sokolow-Lyon criteria, QRS-complex duration, and S-wave amplitude in leads V₂ and V₁ had the strongest correlations with LVIDd. However, the ECG predictive models that were generated only accounted for 17%, 7%, 11%, and 8% of the variance in the right atrial end-systolic area, left atrial end-systolic area, MLVWT, and LVIDd, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that relationships existed between ECG findings and cardiac morphology in the chimpanzees of the present study; however, further research is required to examine whether the predictive models generated can be modified to improve their clinical utility.

P-wave indices as predictors of atrial fibrillation

Background

P‐wave duration (P_DURATION) and P‐wave area (P_AREA) have been linked to risk of atrial fibrillation (AF), but they do not improve the efficacy of Framingham AF risk score. We suggest the incorporation of both variables in one index, the P‐wave area/P‐wave duration (P_{AREA/DURATION}) index, which may be considered an expression of the average amplitude of the P wave that reflects aspects of P‐wave morphology.

Objective

To assess the prognostic value of P‐wave area/P‐wave duration index (P_{AREA/DURATION} index) in lead II together with other P‐wave indices (PWIs) in incidence of AF in the Copenhagen Holter Study.

Methods

The study included 632 men and women, between 55 and 75 years with no apparent heart disease or AF. Baseline standard 12‐lead Electrocardiography (ECGs) were analyzed manually.

Results

The median follow‐up time was 14.7 (14.5;14.9) years. A total of 68 cases of AF and 233 cases of death were recorded. The restricted cubic spline method showed a U‐shaped association between P_{AREA/DURATION} and rate of AF. The lowest quintile of P_{AREA/DURATION} index in lead II was associated with increased rate of AF, HR 2.80 (1.64–4.79). The addition of the new index to the Framingham model for AF improved the model in this population. The P_AREA in lead II in its lowest quintile was also associated with increased rate of AF, HR 2.16 (1.25–3.75), but did not improve the Framingham model. P_DURATION and P‐wave terminal force (PTF) were not significantly associated with AF.

Conclusion

A flat P wave as expressed by a small P_{AREA/DURATION} index in lead II is associated with increased rate of incident AF beyond known AF risk factors.

Normal electrocardiogram values of healthy children

Aim:

Electrocardiography is an important diagnostic tool in the evaluation of cardiac diseases. Normal electrocardiograms are age-dependent and may also vary due to several factors. Many studies have been performed to establish the normal values for the childhood period. The aim of this study was to determine the normal electrocardiograms values for healthy Turkish children in Aydın.

Material and Methods:

All children underwent physical examination by a pediatrician and the electrocardiograms were analyzed by the same pediatrician. In the event of improper or insufficient data, the analyses were repeated. Children with a suspicious electrocardiograms or physical examination were recalled and examined by same pediatric cardiologist in outpatient clinic.

Results:

In this study, electrocardiogram records were collected randomly from 1163 children with a sampling rate of 500 Hz. Of the children, 562 were female (47.4%) and 601 were male (52.6%). The total population was divided into ten age groups. Significant differences in normal limits were determined compared with previously published studies.

Conclusion:

The observed differences in various electrocardiograms parameters could be related to biologic variability and to some technical details such as precordial electrode placement and visual checking of the records in addition to race.

Simulating Arbitrary Electrode Reversals in Standard 12-lead ECG

Electrode reversal errors in standard 12-lead electrocardiograms (ECG) can produce significant ECG changes and, in turn, misleading diagnoses. Their detection is important but mostly limited to the design of criteria using ECG databases with simulated reversals, without Wilson's central terminal (WCT) potential change. This is, to the best of our knowledge, the first study that presents an algebraic transformation for simulation of all possible ECG cable reversals, including those with displaced WCT, where most of the leads appear with distorted morphology. The simulation model of ECG electrode swaps and the resultant WCT potential change is derived in the standard 12-lead ECG setup. The transformation formulas are theoretically compared to known limb lead reversals and experimentally proven for unknown limb-chest electrode swaps using a 12-lead ECG database from 25 healthy volunteers (recordings without electrode swaps and with 5 unicolor pairs swaps, including red (right arm-C1), yellow (left arm-C2), green (left leg (LL) -C3), black (right leg (RL)-C5), all unicolor pairs). Two applications of the transformation are shown to be feasible: 'Forward' (simulation of reordered leads from correct leads) and 'Inverse' (reconstruction of correct leads from an ECG recorded with known electrode reversals). Deficiencies are found only when the ground RL electrode is swapped as this case requires guessing the unknown RL electrode potential. We suggest assuming that potential to be equal to that of the LL electrode. The 'Forward' transformation is important for comprehensive training platforms of humans and machines to reliably recognize simulated electrode swaps using the available resources of correctly recorded ECG databases. The 'Inverse' transformation can save time and costs for repeated ECG recordings by reconstructing the correct lead set if a lead swap is detected after the end of the recording. In cases when the electrode reversal is unknown but a prior correct ECG recording of the same patient is available, the 'Inverse' transformation is tested to detect the exact swapping of the electrodes with an accuracy of (96% to 100%).

Segmentation of the ECG Signal by Means of a Linear Regression Algorithm

The monitoring and processing of electrocardiogram (ECG) beats have been actively studied in recent years: new lines of research have even been developed to analyze ECG signals using mobile devices. Considering these trends, we proposed a simple and low computing cost algorithm to process and analyze an ECG signal. Our approach is based on the use of linear regression to segment the signal, with the goal of detecting the R point of the ECG wave and later, to separate the signal in periods for detecting P, Q, S, and T peaks. After pre-processing of ECG signal to reduce the noise, the algorithm was able to efficiently detect fiducial points, information that is transcendental for diagnosis of heart conditions using machine learning classifiers. When tested on 260 ECG records, the detection approach performed with a Sensitivity of 97.5% for Q-point and 100% for the rest of ECG peaks. Finally, we validated the robustness of our algorithm by developing an ECG sensor to register and transmit the acquired signals to a mobile device in real time.

Mobile Personal Health Monitoring for Automated Classification of Electrocardiogram Signals in Elderly

Mobile electrocardiogram (ECG) monitoring is an emerging area that has received increasing attention in recent years, but still real-life validation for elderly residing in low and middle-income countries is scarce. We developed a wearable ECG monitor that is integrated with a self-designed wireless sensor for ECG signal acquisition. It is used with a native purposely designed smartphone application, based on machine learning techniques, for automated classification of captured ECG beats from aged people. When tested on 100 older adults, the monitoring system discriminated normal and abnormal ECG signals with a high degree of accuracy (97%), sensitivity (100%), and specificity (96.6%). With further verification, the system could be useful for detecting cardiac abnormalities in the home environment and contribute to prevention, early diagnosis, and effective treatment of cardiovascular diseases, while keeping costs down and increasing access to healthcare services for older persons.

Association of Implementation of Practice Standards for Electrocardiographic Monitoring With Nurses' Knowledge, Quality of Care, and Patient Outcomes: Findings From the Practical Use of the Latest Standards of Electrocardiography (PULSE) Trial

BACKGROUND

Although continuous electrocardiographic (ECG) monitoring is ubiquitous in hospitals, monitoring practices are inconsistent. We evaluated implementation of American Heart Association practice standards for ECG monitoring on nurses' knowledge, quality of care, and patient outcomes.

METHODS AND RESULTS

The PULSE (Practical Use of the Latest Standards of Electrocardiography) Trial was a 6-year multisite randomized clinical trial with crossover that took place in 65 cardiac units in 17 hospitals. We measured outcomes at baseline, time 2 after group 1 hospitals received the intervention, and time 3 after group 2 hospitals received the intervention. Measurement periods were 15 months apart. The 2-part intervention consisted of an online ECG monitoring education program and strategies to implement and sustain change in practice. Nurses' knowledge (N=3013 nurses) was measured by a validated 20-item online test, quality of care related to ECG monitoring (N=4587 patients) by on-site observation, and patient outcomes (mortality, in-hospital myocardial infarction, and not surviving a cardiac arrest; N=95 884 hospital admissions) by review of administrative, laboratory, and medical record data. Nurses' knowledge improved significantly immediately after the intervention in both groups but was not sustained 15 months later. For most measures of quality of care (accurate electrode placement, accurate rhythm interpretation, appropriate monitoring, and ST-segment monitoring when indicated), the intervention was associated with significant improvement, which was sustained 15 months later. Of the 3 patient outcomes, only in-hospital myocardial infarction declined significantly after the intervention and was sustained.

CONCLUSIONS

Online ECG monitoring education and strategies to change practice can lead to improved nurses' knowledge, quality of care, and patient outcomes.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01269736.

Accuracy in precordial ECG lead placement: Improving performance through a peer-led educational intervention

BACKGROUND AND OBJECTIVES

Inaccurate electrocardiography (ECG) lead placement may lead to erroneous diagnoses, such as poor R wave progression. We sought to assess the accuracy of precordial ECG lead placement amongst hospital staff members, and to re-evaluate performance after an educational intervention.

METHODS AND RESULTS

100 randomly selected eligible staff members placed sticker dots on a mannequin, their positions were recorded on a radar plot and compared to the correct precordial lead positions. The commonest errors were placing V1 and V2 leads too superiorly, and V5 and V6 leads too medially.Following an educational intervention with the aid of moderated poster presentations and volunteer patients, the study was repeated six months later. 60 subjects correctly placed all leads, compared to 10 in the pre-intervention cohort (P<0.0001) with the proportion achieving correct placement of any lead rising from 0.34 to 0.83, (p<0.0001 for all leads).

CONCLUSION

Incorrect ECG lead placement is common. This may be addressed through regular training incorporated into annual induction processes for relevant health care professionals.

[Right bundle branch block during right ventricular pacing]

INTRODUCTION

We describe the case of a 78-year-old patient who presented for ablation of a wide complex tachycardia with right bundle branch block (RBBB) morphology. A pacemaker spike at the QRS onset indicated supraventricular tachycardia with AV synchronous ventricular pacemaker activation.

METHODS

Correct positioning of the ventricular lead in the right ventricular apex was confirmed by fluoroscopy and echocardiography, excluding malpositioning of the right ventricular lead.

RESULTS

In the electrophysiological study we diagnosed atrial tachycardia with 1:1 AV stimulation by the pacemaker. The ECG, however, presented negative concordance in the precordial leads. Only after shifting the precordial leads V1 and V2 from the 4th to the 2nd intercostal space were all 12 ECG leads in accordance with the clinical tachycardia.

CONCLUSION

Thus, it is suspected that malpositioning of the ECG electrodes generated an apparent RBBB morphology of the clinical tachycardia. Malpositioning of ECG electrodes switches the lead characteristics from horizontal (anterior-posterior) to frontal (cranial-caudal) plane properties. In this situation, the precordial leads V1 and V2 with positive vector in V1 and V2 imitate aVL (V2) and aVR (V1) and can produce an apparent RBBB morphology.

Precordial electrode placement accuracy by nurses in a large midwestern tertiary care hospital

A quality improvement project to increase the knowledge of nurses and the accuracy of electrocardiogram precordial lead placement among intensive care unit and progressive care unit staff was conducted using a single-group, pretest-posttest preexperimental design. Educational interventions based on the theory of planned behavior were developed from focus group data. A tip card, poster, and video were sequentially presented to more than 1,600 nurses. This resulted in statistically significant gains in both knowledge and accuracy (p < 0.02). This project supports the use of focus groups and the theory of planned behavior to guide education related to quality improvement.

Improving Accuracy of Cardiac Electrode Placement: Outcomes of Clinical Nurse Specialist Practice

PURPOSE

The purpose of this quality improvement project was to facilitate a sustainable improvement in the accuracy of cardiac electrode placement for continuous bedside monitoring in intensive care unit patients.

BACKGROUND

Continuous cardiac electrocardiograph monitoring is a standard of practice in critical care areas and is essential to accurate interpretation of cardiac dysrhythmias and early detection of myocardial ischemia. Accurate assessment of electrocardiographs depends on precise placement of electrodes; however, electrodes are often placed inaccurately.

RATIONALE

Evaluation of baseline practice revealed that cardiac electrodes were placed correctly in only 12.5% of patients. The most frequently misplaced electrode was the V lead, followed by lower limb leads.

DESCRIPTION

This project was conducted between July 1, 2013, and October 31, 2013, and involved a multifaceted education program for registered nurse and patient care technician staff on the physiologic basis and technical procedures for cardiac electrode placement. The clinical nurse specialist served as an informal leader, role model, and mentor by developing and empowering unit champions to perform real-time auditing and provide real-time feedback to colleagues.

OUTCOME

At 3 months after intervention, the accuracy of cardiac electrode placement was sustained at greater than 85%, representing a 6-fold improvement above the preintervention baseline.

CONCLUSION

Sustainable improvement in quality requires creation of a culture that supports quality improvement initiatives. As experts in clinical practice, evidence-based practice, and leadership, clinical nurse specialists are optimally positioned to function as change agents whose initiatives measurably improve outcomes.

IMPLICATIONS

This quality improvement project serves as a model for improving accuracy of cardiac electrode placement at the nursing staff level. Future research is necessary to improve outcomes related to accuracy of cardiac electrode placement on the patient and systems levels.

Inter-lead correlation analysis for automated detection of cable reversals in 12/16-lead ECG

BACKGROUND AND OBJECTIVE

A crucial factor for proper electrocardiogram (ECG) interpretation is the correct electrode placement in standard 12-lead ECG and extended 16-lead ECG for accurate diagnosis of acute myocardial infarctions. In the context of optimal patient care, we present and evaluate a new method for automated detection of reversals in peripheral and precordial (standard, right and posterior) leads, based on simple rules with inter-lead correlation dependencies.

METHODS

The algorithm for analysis of cable reversals relies on scoring of inter-lead correlations estimated over 4s snapshots with time-coherent data from multiple ECG leads. Peripheral cable reversals are detected by assessment of nine correlation coefficients, comparing V6 to limb leads: (I, II, III, -I, -II, -III, -aVR, -aVL, -aVF). Precordial lead reversals are detected by analysis of the ECG pattern cross-correlation progression within lead sets (V1-V6), (V4R, V3R, V3, V4), and (V4, V5, V6, V8, V9). Disturbed progression identifies the swapped leads.

RESULTS

A test-set, including 2239 ECGs from three independent sources-public 12-lead (PTB, CSE) and proprietary 16-lead (Basel University Hospital) databases-is used for algorithm validation, reporting specificity (Sp) and sensitivity (Se) as true negative and true positive detection of simulated lead swaps. Reversals of limb leads are detected with Se = 95.5-96.9% and 100% when right leg is involved in the reversal. Among all 15 possible pairwise reversals in standard precordial leads, adjacent lead reversals are detected with Se = 93.8% (V5-V6), 95.6% (V2-V3), 95.9% (V3-V4), 97.1% (V1-V2), and 97.8% (V4-V5), increasing to 97.8-99.8% for reversals of anatomically more distant electrodes. The pairwise reversals in the four extra precordial leads are detected with Se = 74.7% (right-sided V4R-V3R), 91.4% (posterior V8-V9), 93.7% (V4R-V9), and 97.7% (V4R-V8, V3R-V9, V3R-V8). Higher true negative rate is achieved with Sp > 99% (standard 12-lead ECG), 81.9% (V4R-V3R), 91.4% (V8-V9), and 100% (V4R-V9, V4R-V8, V3R-V9, V3R-V8), which is reasonable considering the low prevalence of lead swaps in clinical environment.

CONCLUSIONS

Inter-lead correlation analysis is able to provide robust detection of cable reversals in standard 12-lead ECG, effectively extended to 16-lead ECG applications that have not previously been addressed.

Identification of 4th intercostal space using sternal notch to xiphoid length for accurate electrocardiogram lead placement

OBJECTIVE

Precordial ECG lead placement is difficult in obese patients with increased chest wall soft tissues due to inaccurate palpation of the intercostal spaces. We investigated whether the length of the sternum (distance between the sternal notch and xiphoid process) can accurately predict the location of the 4th intercostal space, which is the traditional location for V1 lead position.

MATERIALS AND METHODS

Fifty-five consecutive adult chest computed tomography examinations were reviewed for measurements.

RESULTS

The sternal notch to right 4th intercostal space distance was 67% of the sternal notch to xiphoid process length with an overall correlation of r=0.600 (p<0.001).

CONCLUSION

The above measurement may be utilized to locate the 4th intercostal space for accurate placement of the precordial electrodes in adults in whom the 4th intercostal space cannot be found by physical exam.

Unusual QRS Pattern in the Early Precordial Leads

An asymptomatic, middle-aged man is found to have a QR pattern in lead V1 and a qR pattern in lead V2 of his ECG obtained during routine life insurance applicant screening. The risk assessment implication of this ECG finding is reviewed.

Telemedicine supported by Augmented Reality: an interactive guide for untrained people in performing an ECG test

BACKGROUND

In many telemedicine applications, the correct use of medical device at the point of need is essential to provide an appropriate service. Some applications may require untrained people to interact with medical devices and patients: care delivery in transportation, military actions, home care and telemedicine training.Appropriate operation of medical device and correct connection with patient's body are crucial. In these scenarios, tailored applications of Augmented Reality can offer a valid support by guiding untrained people at the point of need. This study aims to explore the feasibility of using Augmented Reality in telemedicine applications, by facilitating an acceptable use of biomedical equipment by any unskilled person. In particular, a prototype system was built in order to estimate how untrained users, with limited or no knowledge, can effectively interact with an ECG device and properly placing ECG electrodes on patient's chest.

METHODS

An Augmented Reality application was built to support untrained users in performing an ECG test. Simple markers attached to the ECG device and onto patient's thorax allow camera calibration. Once objects and their pose in the space are recognized, the video of the current scene is enriched, in real-time, with additional pointers, text boxes and audio that help the untrained operator to perform the appropriate sequence of operations. All the buttons, switches, ports of the ECG device together with the location of precordial leads were coded and indicated. Some user's voice commands were also included to improve usability.

RESULTS

Ten untrained volunteers, supported by the augmented reality, were able to carry out a complete ECG test first on a mannequin and then on a real patient in a reasonable time (about 8 minutes on average). Average positioning errors of precordial electrodes resulted less than 3 mm for the mannequin and less than 7 mm for the real patient. These preliminary findings suggest the effectiveness of the developed application and the validity of clinical ECG recordings.

CONCLUSION

This application can be adapted to support the use of other medical equipment as well as other telemedicine tasks and it could be performed with a Tablet or a Smartphone.

Improvement of in-hospital telemetry monitoring in coronary care units: an intervention study for achieving optimal electrode placement and attachment, hygiene and delivery of critical information to patients

BACKGROUND

In-hospital telemetry monitoring is important for diagnosis and treatment of patients at risk of developing life-threatening arrhythmias. It is widely used in critical and non-critical care wards. Nurses are responsible for correct electrode placement, thus ensuring optimal quality of the monitoring. The aims of this study were to determine whether a complex educational intervention improves (a) optimal electrode placement, (b) hygiene, and (c) delivery of critical information to patients (reason for monitoring, limitations in cellular phone use, and not to leave the ward without informing a member of staff).

METHODS

A prospective interventional study design was used, with data collection occurring over two six-week periods: before implementation of the intervention (n=201) and after the intervention (n=165). Standard abstraction forms were used to obtain data on patients' clinical characteristics, and 10 variables related to electrode placement and attachment, hygiene and delivery of critical information.

RESULTS

At pre-intervention registration, 26% of the electrodes were misplaced. Twelve per cent of the patients received information about limiting their cellular phone use while monitored, 70% were informed of the purpose of monitoring, and 71% used a protective cover for their unit. Post-intervention, outcome measures for the three variables improved significantly: use of protective cover (p<0.001), information about the purpose of monitoring (p=0.005) and information about limitations in cellular phone use (p=0.003). Nonetheless, 23% of the electrodes were still misplaced.

CONCLUSION

The study highlights the need for better, continued education for in-hospital telemetry monitoring in coronary care units, and other units that monitor patients with telemetry.

The effect of precordial lead displacement on ECG morphology

Inaccurate electrode placement and differences in inter-individual human anatomies can lead to misinterpretation of ECG examination. The aim of the study was to investigate the effect of precordial electrodes displacement on morphology of the ECG signal in a group of 60 patients with diagnosed cardiac disease. Shapes of ECG signals recorded from precordial leads were compared with signals interpolated at the points located at a distance up to 5 cm from lead location. Shape differences of the QRS and ST-T-U complexes were quantified using the distribution function method, correlation coefficient, root-mean-square error (RMSE), and normalized RMSE. The relative variability (RV) index was calculated to quantify inter-individual variability. ECG morphology changes were prominent in all shape parameters beyond 2 cm distance to precordial leads. Lead V2 was the most sensitive to displacement errors, followed by leads V3, V1, and V4, for which the direction of electrodes displacement plays a key role. No visible changes in ECG morphology were observed in leads V5 and V6, only scaling effect of signal amplitude. The RV ranged from 0.639 to 0.989. Distortions in ECG tracings increase with the distance from precordial lead, which are specific to chosen electrode, direction of displacement, and for ECG segment selected for calculations.

Comparison of twelve-lead electrocardiogram using a glove-based recording system with standard methodology

We tested the clinically relevant diagnostic accuracy of a new electrocardiographic (ECG) recording system incorporating all 10 ECG electrodes in a single-size glove worn on the patient's left arm and placed on the chest. The PhysioGlove (PG) was designed to allow fast, reproducible, electrode placement with only minimal training. The American College of Cardiology/American Heart Association ECG recording guidelines and others have repeatedly highlighted the unacceptable progressive deterioration in ECG accuracy mainly resulting from a performer's lack of proficiency and diligence, leading to frequent electrode misplacement. We studied 428 consenting adult patients with a broad spectrum of anthropomorphic characteristics and ECG and cardiovascular pathologic entities. The chest girth was measured to ascertain the single-size PG clinical diagnostic accuracy in ≥90% of this patient population. For each patient, a PG and standard-cable electrocardiogram were consecutively recorded and interpreted by experienced electrocardiographers. The study included 3 phases: phase 1, run-in (n = 120); phase 2, comparative diagnostic accuracy (n = 208); and phase 3, randomized, blinded, diagnostic accuracy (n = 100). Of the entire study population (n = 428), 92% fit the chest girth range of 85 to 118 cm (34 to 47 in.), representing the reference standard clinical diagnostic PG chest girth range. The phase 2 PG diagnostic accuracy was 91.3% for entire chest girth range and 95.7% for the 89.4% of patients with a chest girth within the reference range. The mean PG diagnostic accuracy in phase 3 was 93% (95% confidence interval 89% to 95%). In conclusion, compared with standard-cable electrocardiograms, the PG demonstrated excellent diagnostic accuracy (93% to 95.7%) in ≥90% of a typical western adult patient population. The PG's ease of use and minimal training requirements offer a promising tool to markedly improve ECG clinical diagnostic accuracy in most adult western patients.

Validity and reliability of Polar® RS800CX heart rate monitor, measuring heart rate in dogs during standing position and at trot on a treadmill

The aim of the present study was to assess criterion validity, and relative and absolute reliability of Polar® RS800CX heart rate monitor, compared to simultaneously recorded electrocardiogram (ECG) data, in measuring heart rate of dogs during standing position and at trot on a treadmill.

METHODS

Heart beats from Polar® RS800CX and Cardiostore ECG were recorded simultaneously during seven continuous minutes in standing position and at trot, in 10 adult healthy dogs. Polar® data was statistically compared to ECG data for a variety of mean beats per minute (BPM), standard deviation and confidence interval. Criterion validity was calculated by Pearson product moment correlation method and intraclass correlation coefficient (ICC2.1). Relative and absolute reliability were calculated by ICC2.1, the Bland and Altman analysis and standard error of measurement (SEM and SEM%).

RESULTS

The correlation, criterion validity, between Polar® and ECG data in standing position was r=0.99 (p<0.0005) and at trot r=0.97 (p<0.0005). Polar® data was not significantly different from ECG data. Mean difference between ECG and uncorrected Polar® data was -0.6 BPM in standing position and -0.6 BPM at trot. Polar® was over- and underestimating ECG data. SEM and SEM% in standing were ±2.6 BPM and 3.0%, at trot ±3.8 BPM and 3.1%, indicating that measurement errors were low.

CONCLUSION

This study showed that the criterion validity and the instrument reliability were excellent in Polar® RS800CX heart rate measuring system. The equipment seemed to be valid and reliable in measuring BPM in the dogs studied during submaximal cardiovascular conditions such as in standing position and at trot on a treadmill.

Assessing the knowledge of sudden unexpected death in the young among Canadian medical students and recent graduates: a cross-sectional study

OBJECTIVE

To determine the level of knowledge concerning Sudden Unexpected Death in the Young (SUDY) among Canadian medical students and recent graduates (≤5 years after graduating).

DESIGN

A cross-sectional study was conducted by distributing a standardised, multiple choice, online questionnaire which assessed basic knowledge of SUDY.

SETTING

Canadian medical schools and residency training programmes.

PARTICIPANTS

614 Canadian medical students (in either their penultimate or final year) and recent graduates (≤5 years after graduating) completed an anonymous online questionnaire.

PRIMARY AND SECONDARY OUTCOME MEASURES

The level of knowledge regarding molecular aetiology, clinical presentation, pharmacological management and modes of inheritance of six of the commonest conditions causing SUDY, including hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia (CPVT), long QT syndrome (LQT) and Wolff-Parkinson White syndrome (WPW), were compared between medical students and recent graduates. Questions were broken down into basic knowledge and advanced categories and analysed as a secondary outcome measure.

RESULTS

Of 614 responses, approximately two-thirds were answered by recent graduates, who generally scored 10% higher on all subject categories than medical students. Overall, questions regarding HCM were best answered (40%), followed by WPW syndrome (32%), CPVT (30%), ARVC (23%), Brugada syndrome (21%) and LQT syndrome (17%). Questions categorised as basic knowledge were answered 30% and 39% correctly in medical student and recent graduate groups, respectively, and those in the advanced category were answered 20% and 25% correctly.

CONCLUSIONS

Survey respondents fared poorly when answering questions regarding SUDY, which may be a reflection of inadequate medical education regarding these disorders. Standardised teaching regarding SUDY needs to occupy a stronger focus in Canadian medical curricula in order to prevent more unnecessary deaths by these syndromes in the future.

Proposed bedside maneuver to facilitate accurate anatomic orientation for correct positioning of ECG precordial leads V1 and V2: a pilot study

BACKGROUND

Misplacement of right precordial electrocardiogram (ECG) electrodes superiorly is a prevalent procedural error that may lead to false findings of T-wave inversion or QS complexes in V2-possibly triggering wasteful utilization of health care resources. Standard technique for proper placement of V1-V2 entails initial palpation for the sternal angle, pointing to the second intercostal space (ICS), followed by lead fixation at the fourth ICS.

STUDY OBJECTIVE

Because adherence to this approach may be limited by lack of a visual landmark for the second ICS, we assessed an alternative technique.

METHODS

The evaluated technique involved placement of the patient's hand up against the base of his/her neck (H→N maneuver) to help demarcate visually a specific point "X" on the chest.

RESULTS

Of 112 patients studied, "X" landed on the first rib in 2.7%, first ICS in 7.1%, second rib in 56.3%, second ICS in 33.0%, and third rib in 0.9%. Thus, in 89.3% (95% confidence interval 83.6-95.0%) of cases (93.3% of men, 84.6% of women; p=0.13), the second ICS could be identified by H→N via the following simple rule: Utilize "X" if it overlies an ICS; or the immediately subjacent ICS if "X" overlies a rib.

CONCLUSION

The H→N maneuver provides a primarily visual approach to identifying the second ICS and, thereby, the fourth ICS for affixing V1-V2. If the present initial experience is confirmed, H→N might merit consideration as an educational tool to promote anatomically correct placement of these precordial leads, a prerequisite to diminishing the incidence of ECG procedure-related "septal ischemia/infarction."

Importance of recognizing pseudo-septal infarction due to electrocardiographic lead misplacement

Awareness of the problem of false electrocardiographic diagnosis of septal infarction due to cranially misplaced precordial leads V1 and V2, a common technical error, is important because this pseudo-pathologic finding can trigger unnecessary medical procedures and have other adverse sequelae. The non-trivial nature of this problem is emphasized by the case of a patient in whom the misdiagnosis caused loss of an employment opportunity. We demonstrate how P wave morphology in lead V2 can aid the clinician in suspecting erroneous right precordial lead placement in cases of apparent septal infarction. Ultimately, improved education of health care personnel regarding accurate precordial lead positioning technique is needed to minimize the occurrence of this electrocardiographic misdiagnosis.