Dr. Walter J. Hoyt Profile

Dr. Walter J. Hoyt

at Ochsner Health System

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Author

Publications (7)

Proceedings Article | 13 March 2024 Presentation + Paper

PSOCT, NIRS, and optical mapping of low voltage zones in atrial fibrillation

Michael Douglass, Lydia Akino, Juan Perez, Haiqiu Yang, Jonah Majumder, Walter Hoyt, Ohad Ziv, Kenneth Laurita, Christine Hendon, Andrew Rollins

Proceedings Volume 12819, 128190R (2024) https://doi.org/10.1117/12.3001724

KEYWORDS: Atrial fibrillation, Near infrared spectroscopy, Tissues, Ablation, In vivo imaging, Tissue optics, Heart, Birefringence, Veins, Pathology

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Atrial fibrillation (AF) is the most common arrhythmia worldwide. An increasingly common treatment option is catheter ablation. During this procedure, the clinician steers a catheter into the left atrium and ablates a lesion fence around the pulmonary veins, a common source of ectopic signals. This lesion fence blocks arrhythmogenic tissue from initiating an erroneous heartbeat. However, if the disease has progressed from paroxysmal to persistent, pathogenic tissue exists throughout the atrium, and common ablation schemes are not as effective. In this case, technologies exist to electroanatomically map the atrium and guide clinicians in targeting adjunctive AF ablation targets. Low voltages mapped in vivo are a well-documented way of identifying atrial fibrosis, an important substrate for AF. Ablating low voltage zones in patients with a more developed disease can help terminate AF and improve long-term outcomes, but low voltage measurements are not specific to fibrosis. Treatment results vary because the targeting that electroanatomical mapping provides is incomplete. Our group has shown that polarization-sensitive optical coherence tomography (PSOCT) and near infrared spectroscopy (NIRS) can monitor lesion formation in vivo and differentiate tissue types in the atrium. Now, we are investigating the technology’s utility in identifying AF targets prior to ablation. We have collaborated in developing a swine model of AF that shows the atria remodels during the diseased state. Because of this, we can electroanatomically map these diseased hearts in vivo to measure low voltage zones. Subsequently, we examine the left atrium ex vivo using benchtop PSOCT, NIRS, and optical mapping (OM) and register these optical measurements to the in vivo low voltage zones. We show that OM confirms abnormal conduction, while PSOCT- and NIRS-derived metrics have promise for identifying low voltage zones. We confirm these measures with histological identification of fibrosis. This suggests the feasibility of using PSOCT-NIRS at the catheter tip to detect AF ablation targets.

Proceedings Article | 13 March 2024 Presentation + Paper

A multimodal PSOCT-NIRS catheter for ablation of atrial fibrillation

Michael Douglass, Reza Mohammadpour, Gauri Srikumar, Alice Qian, Juan Perez, Jonah Majumder, Christine Hendon, Kenneth Laurita, Walter Hoyt, Ohad Ziv, Andrew Rollins

Proceedings Volume 12834, 1283407 (2024) https://doi.org/10.1117/12.3006074

KEYWORDS: Ablation, Near infrared spectroscopy, Atrial fibrillation, Tissues, Optical coherence tomography, Heart, Radiofrequency ablation, Polarization, In vivo imaging, Birefringence

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Proceedings Article | 14 March 2023 Presentation + Paper

Polarization-Sensitive Optical Coherence Tomography (PSOCT) for identifying and analyzing gaps in lesion lines during ex vivo simulated radiofrequency ablation procedure

Michael Douglass, Juan Perez, Lydia Akino, Haiqiu Yang, Walter Hoyt, Ohad Ziv, Kenneth Laurita, Christine Hendon, Andrew Rollins

Proceedings Volume 12355, 1235503 (2023) https://doi.org/10.1117/12.2650838

KEYWORDS: Ablation, Tissues, Atrial fibrillation, Radiofrequency ablation, Polarization, Birefringence, Optical coherence tomography

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Proceedings Article | 7 March 2022 Presentation

Cardiac tissue substrate mapping with polarization-sensitive optical coherence tomography

Xiaowei Zhao, Ohad Ziv, Michael Douglass, Walter Hoyt, Michael Jenkins, Christopher Snyder, Christine Hendon, Kenneth Laurita, Andrew Rollins

Proceedings Volume PC11936, PC1193606 (2022) https://doi.org/10.1117/12.2607820

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Proceedings Article | 5 March 2021 Poster + Presentation

Quantitative assessment of transmurality of in vivo left atrium radiofrequency ablation lesions by polarization-sensitive optical coherence tomography

Xiaowei Zhao, Ohad Ziv, Walter Hoyt, Michael Jenkins, Christopher Snyder, Kenneth Laurita, Andrew Rollins

Proceedings Volume 11630, 116301Y (2021) https://doi.org/10.1117/12.2583918

KEYWORDS: Radiofrequency ablation, Optical coherence tomography, In vivo imaging, Atrial fibrillation, Image quality, Tissues, Veins, Real time imaging, Photovoltaics, Image resolution

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Proceedings Article | 5 March 2021 Presentation

Optical coherence tomography for transseptal puncture procedure guidance

Xiaowei Zhao, Orhan Kilinc, Michael Douglass, Walter Hoyt, Kaushal Dosani, Michael Jenkins, Ohad Ziv, Kenneth Laurita, Christopher Snyder, Andrew Rollins

Proceedings Volume 11621, 1162105 (2021) https://doi.org/10.1117/12.2583457

KEYWORDS: Optical coherence tomography, Tissue optics, In vivo imaging, Heart, Fluoroscopy, Visualization, Tissues, Safety, Real time imaging, Ionizing radiation

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Proceedings Article | 9 March 2020 Presentation

Polarization sensitive optical coherence tomography-guided percutaneous radiofrequency ablation in left atrium of living swine (Conference Presentation)

Xiaowei Zhao, Ohad Ziv, Reza Mohammadpour, Benjamin Crosby, Walter Hoyt, Kaushal Dosani, Michael Jenkins, Christopher Snyder, Kenneth Laurita, Andrew Rollins

Proceedings Volume 11215, 1121509 (2020) https://doi.org/10.1117/12.2551530

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Showing 5 of 7 publications

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