Head orientation and electrode placement potentially influence fetal scalp ECG waveform
Publication year
2019Source
PLoS One, 14, 10, (2019), article e0223282ISSN
Publication type
Article / Letter to editor

Display more detailsDisplay less details
Organization
Radiation Oncology
Journal title
PLoS One
Volume
vol. 14
Issue
iss. 10
Subject
Radboudumc 9: Rare cancers RIHS: Radboud Institute for Health SciencesAbstract
BACKGROUND: Fetal monitoring based on electrocardiographic (ECG) morphology is obtained from a single unipolar fetal scalp electrode. Ideally, it should be obtained from multiple leads, as ECG waveform depends on alignment between electrode and electrical heart axis. This alignment is unknown in fetuses. Besides, fetuses are surrounded by conductive media, which may influence ECG waveform. We explored the influence of electrode position and head orientation on ECG waveforms of unipolar and bipolar scalp ECGs recorded in air and in conductive medium. METHODS: We recorded ECGs in one adult subject at five different scalp positions in five different head orientations both in dry and immersed conditions. The ratio between T-amplitude and QRS-amplitude (T/QRS ratio) of unipolar and bipolar scalp ECGs was determined and compared between all conditions. RESULTS: In the dry condition, we observed in the unipolar leads little to no difference between different electrode positions (maximal T/QRS difference 0.00-0.01) and minor differences between head orientations (0.02-0.03), whereas bipolar leads showed no recognizable ECG signal at all. During the immersed condition, we found variation in the unipolar leads, both between electrode positions (maximal T/QRS difference 0.02-0.05) and between head orientations (0.03-0.06). Bipolar leads showed different ECG signals in contrasting head orientations. CONCLUSIONS: Both unipolar and bipolar scalp lead-derived ECG waveforms are influenced by electrode position and head orientation when the subject is submerged in a conductive medium. Fetal monitoring based on single scalp lead ECG waveform might be suboptimal, as it lacks correction for fetal head orientation and electrode position.
This item appears in the following Collection(s)
- Academic publications [227437]
- Electronic publications [107154]
- Faculty of Medical Sciences [86157]
- Open Access publications [76296]
Upload full text
Use your RU credentials (u/z-number and password) to log in with SURFconext to upload a file for processing by the repository team.