Background: Automated systems for substrate mapping in the context of ventricular tachycardia (VT) ablation may annotate far-field rather than near-field signals, rendering the resulting maps hard to interpret. Additionally, quantitative assessment of local conduction velocity (LCV) remains an unmet need in clinical practice. We evaluate whether a new late potential map (LPM) algorithm can provide an automatic and reliable annotation and localized bipolar voltage measurement of ventricular electrograms (EGMs) and if LCV analysis allows recognizing intrascar conduction corridors acting as VT isthmuses.
Methods: In 16 patients referred for scar-related VT ablation, 8 VT activation maps and 29 high-resolution substrate maps from different activation wavefronts were obtained. In offline analysis, the LPM algorithm was compared to manually annotated substrate maps. Locations of the VT isthmuses were compared with the corresponding substrate maps in regard to LCV.
Results: The LPM algorithm had an overall/local abnormal ventricular activity (LAVA) annotation accuracy of 94.5%/81.1%, which compares to 83.7%/23.9% for the previous wavefront algorithm. The resultant maps presented a spatial concordance of 88.1% in delineating regions displaying LAVA. LAVA median localized bipolar voltage was 0.22 mV, but voltage amplitude assessment had modest accuracy in distinguishing LAVA from other abnormal EGMs (area under the curve: 0.676; p < .001). LCV analysis in high-density substrate maps identified a median of two intrascar conduction corridors per patient (interquartile range: 2-3), including the one acting as VT isthmus in all cases.
Conclusion: The new LPM algorithm and LCV analysis may enhance substrate characterization in scar-related VT.
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http://dx.doi.org/10.1111/jce.15470 | DOI Listing |
Eur Respir J
November 2024
Department of Medicine, University of British Columbia, Vancouver, BC, Canada
Clin Transl Gastroenterol
November 2024
Department of Gastroenterology, Precision Medicine Unit, São João University Hospital, Porto, Portugal.
Background: Thermal spray coatings have emerged as a pivotal technology in materials engineering, primarily for augmenting the characteristics related to wear and tribology of metallic substrates.
Method: This study aimes to delve into applying High-Velocity Oxygen Fuel (HVOF) thermalsprayed WC-Co nanocoatings on Titanium Grade-5 alloy (Ti64). The coating process, utilizing nano-sized WC-Co powder, undergoes systematic optimization of HVOF parameters, encompassing the flow rate of carrier gas, powder feed rate, and nozzle distance.
Comput Methods Programs Biomed
June 2024
Institute of Cardio-Cerebrovascular Medicine, Central Hospital of Dalian University of Technology, Dalian, Liaoning 116033, China; School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian, Liaoning 116024, China. Electronic address:
Comput Biol Med
May 2024
Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing, China.
The reduced-order lumped parameter model (LPM) has great computational efficiency in real-time numerical simulations of haemodynamics but is limited by the accuracy of patient-specific computation. This study proposed a method to achieve the individual LPM modeling with high accuracy to improve the practical clinical applicability of LPM. Clinical data was collected from two medical centres comprising haemodynamic indicators from 323 individuals, including brachial artery pressure waveforms, cardiac output data, and internal carotid artery flow waveforms.
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