What are the common themes surrounding the topic of electrocardiogram lead placement accuracy: A literature review
Posted on 22nd May 2020 by Luke Prout
During the final year of their Paramedic Science (BSc Hons) course at Oxford Brookes University, students carry out a literature review and critical appraisal of a topic relevant to their future practice. This blog presents the abstract of a literature review on ‘Electrocardiogram (ECG) lead placement accuracy’. Other Paramedic topic blogs can be found here.
The electrocardiogram (ECG) is a common investigative tool used within the healthcare setting. To carry out an ECG, electrodes must be placed accurately upon a patient’s chest. The accuracy to which electrodes are placed appears to influence the morphology produced. This variability in placement affects the relative applicability of the ECG in aiding a diagnosis, potentially creating false positive or false negative readings and changing how a patient is managed.
The purpose of the literature review was to identify and explore several themes within the topic of ECG placement accuracy research. The following themes were identified and explored within the literature review.
- Placement on Women
- Morphological change due to misplacement
- Why misplacement occurs
The databases PubMed, Cinahl and Cochrane were searched using a structured search protocol and snowball searching. Identified literature were then screened through a sensitive set of inclusion and exclusion criteria with duplicates removed. Seven papers were accepted into the literature review. Critical appraisal was carried out using the CASP and EPHPP appraisal tools. Thematic analysis was employed to identify the themes present within the selected literature. Finally, the themes identified were discussed and analysed.
Of the seven papers identified: Four contained themes relating to education, five contained themes relating to ECG lead placement in women, seven contained themes relating to morphological changes due to misplacement, and five contained themes relating to why misplacement occurs. Much of the selected literature was quantitative in design, increasing the difficulty of extracting concise qualitative themes.
The use of an educational intervention was found to be an effective method of increasing ECG placement accuracy (Medani et al., 2018; Wirt et al., 2014). Further research is required to assess the applicability of such techniques within various healthcare environments and the relative effectiveness in professionals of differing educational attainment.
Women were addressed on several points. There appeared to be an underrepresentation of women within the research selected; a well-documented phenomenon in clinical research (Liu and Mager, 2016). Reproducibility and accuracy were found to be higher when ECG electrodes were placed upon the breast versus under the breast. Several morphological presentations such as right bundle branch block and poor R-wave progression were found to be produced by placing the leads below the breast on women. The technique of placing ECG electrodes on women was found to be an appropriate method of lead placement, however consideration must be made for breast implants, breast protuberance, and BMI.
Erroneous morphological changes such as ST-elevation, and right bundle branch block were associated with ECG electrode misplacement (Gregory et al., 2019; McCann et al., 2007; Medani et al., 2018).
These misrepresentations may lead to mismanagement of patients, or equally the trivialisation of such morphological changes due to their association with lead misplacement (Gregory et al., 2019; McCann et al.,2007; Medani et al., 2018; Rajaganeshan et al., 2008). Poor placement accuracy was found to occur due to poor technique in identifying electrode locations and a belief that the accuracy of electrode placement had no effect on interpretation (Medani et al., 2018; Rajaganeshan et al., 2008).