Optimal configuration of adhesive ECG patches suitable for long-term monitoring of a vectorcardiogram

Abstract

The purpose of this study was to develop optimal configuration of adhesive ECG patches placement on the torso, which would provide the best agreement with the Frank orthogonal ECGs. Ten seconds of orthogonal ECG followed by 3-5min of ECGs using patches at 5 different locations simultaneously on the torso were recorded in 50 participants at rest in sitting position. Median beat was generated for each ECG and 3 patch ECGs that best correlate with orthogonal ECGs were selected for each participant. For agreement analysis, spatial QRS-T angle, spatial QRS and T vector characteristics, spatial ventricular gradient, roundness, thickness and planarity of vectorcardiographic (VCG) loops were measured. Key VCG parameters showed high agreement in Bland-Altman analysis (spatial QRS-T angle on 3-patch ECG vs. Frank ECG bias 0.3 (95% limits of agreement [-6.23;5.71 degrees]), Lin's concordance coefficient=0.996). In conclusion, newly developed orthogonal 3-patch ECG can be used for long-term VCG monitoring.

Keywords: ECG patch; QRS-T angle; Vectorcardiogram.

Figure 1

A: Placement of the patches (P1, P2, P3, P4, P5) on the torso. P1 is placed horizontally over the 3^rd intercostal space, between the left parasternal and mid-clavicular line; P2 is placed horizontally over the 5^th intercostal space between the left parasternal and mid-clavicular lines; P3 is placed vertically at left parasternal line over the 4^th intercostal space; P4 is placed at the horizontal level of P2 at the left anterior axillary line; P5 is placed at the horizontal level of P2 at the left mid-axillary line. B: Optimal configuration of patches. X: placed horizontally over the 5^th intercostal space between the left parasternal and mid-clavicular lines; Y: placed vertically at left parasternal line over the 4^th intercostal space; Z: placed at the horizontal level of X at the left mid-axillary line.

Figure 2

Representative example of Frank orthogonal X-, Y-, Z- ECG (blue) and patch XYZ ECG leads (red) in a study participant. A: XYZ leads. B: Vectorcardiographic loops

Figure 3

Representative example of the advantage of multi-lead ECG-analysis. Artefacts on Y-lead could be mislabelled if this would be the only ECG patch used. Simultaneously recorded X and Z leads are free from artefacts at the same time point (dashed box), which increases accuracy of the automated ECG analyses.