New Insights into Non-Invasive His Bundle Potential Detection on High Resolution Body Surface Recordings

Nolwenn Tan1, Romain Tixier2, Josselin Duchateau2, Laura Bear3, Remi Dubois1
1IHU LIRYC, 2Bordeaux University Hospital, 3IHU-LIRYC


Introduction: Abnormal conduction of the His bundle can lead to AV block and in more serious cases to arrhythmias. The His bundle potential has a high frequency and low amplitude making its detection challenging. Currently, the His-Ventricular (HV) interval can only be recorded invasively. This study presents a novel non-invasive method to detect the HV interval from high-resolution body surface signals. Method: 35 patients (53±16.5 years) were included in this study. All patients underwent an invasive electrophysiological study to obtain the true HV interval. Prior to each procedure, body surface signals were recorded using 128 electrodes sampled at 2048 Hz during 8 minutes. Baseline cancelling and/or a notch filter were applied to the body surface signals before signal averaging was performed using only the beats occurring during the exhalation phase of respiration. 4 wide bipolar signals (2 electrodes spaced 50 mm) in the vertical, horizontal, right diagonal and left diagonal directions were computed, as well as Laplacians signals. Bipolar and Laplacian signals were highpass filtered at 30 Hz. Results: Non-invasive HV interval measurements were not performed on 2 (6%) patients because body surface signals were too noisy. His potentials were invisible on the bipolar signals of 5 (14%) patients and on the Laplacian signals of 7 patients (20%). Comparison between remaining patients demonstrated invasive HV interval (58.5±15 ms) and non-invasive HV interval (53.6±14 ms) measured on bipolar signals showed an encouraging squared correlation coefficient (SCC=0.66). HV intervals measured on Laplacian electrodes (53.8±18 ms) were less correlated (SCC=0.50) with invasive measurements. Conclusion: This study shows promising results that the HV interval can be measured non-invasively using a new approach based on large localized bipolar signals and Laplacian signals. Future improvements such as recording simultaneously invasive and non-invasive HV activities and studying more patients should be done to assess better results.