The evaluation of a precordial ECG BELT: technologist satisfaction and accuracy of recording

Modified precordial lead ECG SafOne on electrocardiography recordings

Adaptability in precordial lead placement is one of the sources of electrocardiography inaccuracy. The present experimental study aimed to investigate the modified precordial lead ECG SafOne on electrocardiography recordings. Fourteen subjects were selected using purposive sampling. All the artefacts that emerged in the ECG recording results from the subjects using both the modified precordial lead ECG SafOne and precordial lead standard ECG were measured and identified. Data were analysed using a t test to examine the difference in the artefacts from all ECG recordings. The electrocardiography recordings of males aged 21–25 years using modified precordial lead ECG SafOne showed that out of 168 precordial leads from 14 subjects, two indicated artefact images in lead II (1.19%) and three in lead III (1.79%). The statistical test showed no significant difference in terms of artefacts that emerged in the electrocardiography recording results from both standard ECG and modified precordial lead ECG SafOne (p = 0.096). The modified precordial lead ECG SafOne showed no significant effect on ECG recordings related to artefacts. Additionally, the precordial lead ECG SafOne had no substantial difference in the presence of artefacts compared to the standard ECG. Therefore, ECG SafOne was usable as an ECG precordial lead for electrocardiography recording.

Human factors analysis of the CardioQuick Patch®: A novel engineering solution to the problem of electrode misplacement during 12-lead electrocardiogram acquisition

INTRODUCTION

The CardioQuick Patch® (CQP) has been developed to assist operators in accurately positioning precordial electrodes during 12-lead electrocardiogram (ECG) acquisition. This study describes the CQP design and assesses the device in comparison to conventional electrode application.

METHODS

Twenty ECG technicians were recruited and a total of 60 ECG acquisitions were performed on the same patient model over four phases: (1) all participants applied single electrodes to the patient; (2) all participants were then re-trained on electrode placement and on how to use the CQP; (3) participants were randomly divided into two groups, the standard group applied single electrodes and the CQP group used the CQP; (4) after a one day interval, the same participants returned to carry out the same procedure on the same patient (measuring intra-practitioner variability). Accuracy was measured with reference to pre-marked correct locations using ultra violet ink. NASA-TLK was used to measure cognitive workload and the Systematic Usability Scale (SUS) was used to quantify the usability of the CQP.

RESULTS

There was a large difference between the minimum time taken to complete each approach (CQP=38.58s vs. 65.96s). The standard group exhibited significant levels of electrode placement error (V1=25.35mm±29.33, V2=18.1mm±24.49, V3=38.65mm±15.57, V4=37.73mm±12.14, V5=35.75mm±15.61, V6=44.15mm±14.32). The CQP group had statistically greater accuracy when placing five of the six electrodes (V1=6.68mm±8.53 [p<0.001], V2=8.8mm±9.64 [p=0.122], V3=6.83mm±8.99 [p<0.001], V4=14.90mm±11.76 [p<0.001], V5=8.63mm±10.70 [p<0.001], V6=18.13mm±14.37 [p<0.001]). There was less intra-practitioner variability when using the CQP on the same patient model. NASA TLX revealed that the CQP did increase the cognitive workload (CQP group=16.51%±8.11 vs. 12.22%±8.07 [p=0.251]). The CQP also achieved a high SUS score of 91±7.28.

CONCLUSION

The CQP significantly improved the reproducibility and accuracy of placing precordial electrodes V1, V3-V6 with little additional cognitive effort, and with a high degree of usability.

The effects of electrode misplacement on clinicians' interpretation of the standard 12-lead electrocardiogram

INTRODUCTION

This study investigates how a particular incorrect electrode configuration affects the 12-lead Electrocardiogram (ECG).

METHODS

A correct and an incorrect 12-lead ECG were extracted from a 192-lead BSPM. This was done for 232 BSPMs yielding 464 12-lead ECGs. The particular incorrect ECG involved displacing electrodes V1 and V2 in the second intercostal space whilst also offsetting the remaining electrodes. These ECGs were examined in two stages: (a) analysis of the effects of electrode misplacement on signal morphology and (b) analysis of how often the incorrect electrode configuration changed the diagnosis of two clinicians in a random sample of 75 patients.

RESULTS

According to the Root Mean Square Error (RMSE) of the difference between PQRST intervals in the correct and incorrect ECGs, lead V2 is the most affected lead (mean: 185 μV ± 82 μV), followed by lead V4 (mean: 114 μV ± 59 μV) and lead V1 (mean: 100 μV ± 47 μV). It was found that if the incorrect electrode configuration is applied, there is a 17% to a 24% chance the diagnostic interpretation will be different. Quantified using Similarity Coefficient (SC) leads V1 and V2 were found to be more alike when misplaced in the second intercostal space. The average SC between these leads when correctly placed was 0.08 (± 0.65), however when incorrectly placed, the average SC was 0.43 (± 0.3).

CONCLUSION

There is a reasonable chance this particular incorrect electrode configuration will change the diagnosis of the 12-lead ECG. This highlights the importance of developing algorithms to detect electrode misplacement along with better education regarding ECG acquisition.

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."

The V-Quick patch versus the standard 12-lead ECG system: time is the essence

Introduction

The V-Quick patch template system is compared with the standard 12-lead electrocardiogram (ECG) acquisition technique in this paper. The objectives of the study were: (a) to study and compare the time taken to produce the printed 12-lead ECG and (b) to look at the level of agreement when the ECGs were compared by two blinded, independent assessors.

Methods

One hundred and fifty each of male and female volunteers signed an informed consent form to participate in the clinical study. Nurses were put through a 4-h training session to familiarise themselves with the V-Quick patch system. The timings were measured with a stopwatch with the specific start and end points defined. The final ECG printouts were then compared by two blinded, independent assessors for several set criteria.

Results

The V-Quick patch system was proved to be significantly faster than the standard 12-lead system in the acquisition of the ECG in both male and female volunteers. The time taken in male volunteers was also noted to be significantly faster than in female volunteers.

Conclusion

The two assessors shared a 100% agreement level when comparing the ECGs acquired by both techniques in the same individual (intra-assessor agreement) and when each ECG was read by the two assessors separately (inter-assessor agreement).