scholarly journals Use of Excitation Emission Matrices to Reveal Spectral Changes Caused by Radiofrequency Ablation of Cardiac Tissue

2016 ◽  
Vol 110 (3) ◽  
pp. 494a
Author(s):  
Mohammed Aljishi ◽  
Huda Asfour ◽  
Luther Swift ◽  
Narine Muselimyan ◽  
Tigran Chahbazian ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Cardiac Tissue ◽  
Spectral Changes ◽  
Excitation Emission Matrices

Abstract 430: Spectral Changes Caused by Radiofrequency Ablation of Cardiac Tissue

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Mohammed Aljishi ◽  
Huda Asfour ◽  
Tigran Chahbazian ◽  
Narine Muselimyan ◽  
Luther Swift ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Visual Information ◽  
Thermal Ablation ◽  
Cardiac Tissue ◽  
Cardiac Activity ◽  
Soret Band ◽  
Quantitative Information ◽  
Thermal Coagulation ◽  
Spectral Changes ◽  
Nadh Fluorescence

Persistent atrial fibrillation is commonly treated using an endoscopic catheter to eliminate anomalous sources of cardiac activity via thermal ablation. However, the procedure lacks real-time feedback. Newly developed radiofrequency ablation (RFA) catheters include a fiberoptic bundle through which visual information of tissue conditions may be collected offering an opportunity to reveal subtle differences in tissue physiology. Currently little is known about the spectral changes caused by RFA. We hypothesized that by comparing spectral changes in various areas in the heart before and after RFA, optical signatures can be used to distinguish healthy cardiac tissue from thermally ablated tissue. Excitation emission matrices (EEM) were acquired from excised porcine hearts (300-600nm). Distinct EEMs were collected from the endocardium of the left atria, ventricle, and aorta. Additionally, the fluorescence and reflectance profiles of each tissue were altered by thermal ablation. In the ventricular muscle, a reduction in the NADH fluorescence peak (360/460nm excitation/emission maxima) was most prominent. While in the aorta, collagen and elastin fluorescence peaks fused and broadened upon ablation. Changes in atrial tissue included a drop in NADH fluorescence and an overall increase in reflectance. The latter is likely caused by thermal coagulation of heme-containing proteins such as myoglobin and a weaker absorption within the Soret band. We concluded that optical signals revealed by EEMs offer quantitative information that can be used to develop diagnostic catheters, including hyperspectral imaging protocols to discern spectral changes elicited by RFA treatment.

scholarly journals Optical signatures of radiofrequency ablation in biological tissues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pranav Lanka ◽  
Kalloor Joseph Francis ◽  
Hindrik Kruit ◽  
Andrea Farina ◽  
Rinaldo Cubeddu ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Treatment Time ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Tissue Response ◽  
Optical Monitoring ◽  
Diffuse Optical Spectroscopy ◽  
Spectral Changes ◽  
Scattering Spectra ◽  
Optical Behavior

AbstractAccurate monitoring of treatment is crucial in minimally-invasive radiofrequency ablation in oncology and cardiovascular disease. We investigated alterations in optical properties of ex-vivo bovine tissues of the liver, heart, muscle, and brain, undergoing the treatment. Time-domain diffuse optical spectroscopy was used, which enabled us to disentangle and quantify absorption and reduced scattering spectra. In addition to the well-known global (1) decrease in absorption, and (2) increase in reduced scattering, we uncovered new features based on sensitive detection of spectral changes. These absorption spectrum features are: (3) emergence of a peak around 840 nm, (4) redshift of the 760 nm deoxyhemoglobin peak, and (5) blueshift of the 970 nm water peak. Treatment temperatures above 100 °C led to (6) increased absorption at shorter wavelengths, and (7) further decrease in reduced scattering. This optical behavior provides new insights into tissue response to thermal treatment and sets the stage for optical monitoring of radiofrequency ablation.

Treatment of Arrhythmias by Radiofrequency Ablation

2013 ◽  
Author(s):  
M. Erol Ulucakli ◽  
Evan P. Sheehan
Keyword(s):  
Radiofrequency Ablation ◽  
Cardiac Tissue ◽  
Clinical Applications ◽  
Bioheat Transfer ◽  
Temperature Profiles ◽  
Cellular Injury ◽  
Rf Ablation ◽  
Transcatheter Therapy ◽  
Wide Range ◽  
Primary Modality

Radiofrequency ablation may be described as a thermal strategy to destroy tissue by increasing its temperature and causing irreversible cellular injury. Radiofrequency ablation is a relatively new modality which has found use in a wide range of medical applications and gained acceptance. RF ablation has been used to destroy tumors in the liver, prostate, breasts, lungs, kidneys, bones, and eyes. One of the early clinical applications was its use in treating supraventricular arrhythmias by selectively destroying cardiac tissue. Radiofrequency ablation has become established as the primary modality of transcatheter therapy for the treatment of symptomatic arrhythmias. Radiofrequency catheter ablation of cardiac arrhythmias was investigated using a finite-element based solution of the bioheat transfer equation. Spatial and temporal temperature profiles in the cardiac tissue were visualized.

Radiofrequency Catheter Ablation of Cardiac Arrhythmias

2011 ◽  
Author(s):  
M. Erol Ulucakli
Keyword(s):  
Radiofrequency Ablation ◽  
Catheter Ablation ◽  
Cardiac Arrhythmias ◽  
Radiofrequency Catheter Ablation ◽  
Cardiac Tissue ◽  
Bioheat Transfer ◽  
Temperature Profiles ◽  
Cellular Injury ◽  
Wide Range ◽  
Primary Modality

Radiofrequency ablation could be described as a thermal strategy to destroy a tissue by increasing its temperature and causing anirreversible cellular injury. Radiofrequency ablation is a relatively new modality which has found use in a wide range of medical applications and gained acceptance. RF ablation has been used in destroying tumors in liver, prostate, breast, lung, kidney, bones, and the eye. One of the early applications in clinical setting was its use in treating supraventricular arrhythmias by selectively destroying cardiac tissue. Radiofrequency ablation has become established as the primary modality of transcatheter therapy for the treatment of symptomatic arrhythmias. Radiofrequency catheter ablation of cardiac arrhythmias were investigated using a finite-element based solution of bioheat transfer equation. Spatial and temporal temperature profiles in the cardiac tissue were visualized.

scholarly journals Key factors behind autofluorescence changes caused by ablation of cardiac tissue

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Narine Muselimyan ◽  
Huda Asfour ◽  
Narine Sarvazyan
Keyword(s):  
Diffuse Reflectance ◽  
Cardiac Tissue ◽  
Clinical Implementation ◽  
Key Factors ◽  
Spectral Changes ◽  
Post Process ◽  
Real Time Visualization ◽  
Key Variables ◽  
Endocardial Layer ◽  
Autofluorescence Changes

Abstract Radiofrequency ablation is a commonly used clinical procedure that destroys arrhythmogenic sources in patients suffering from atrial fibrillation and other types of cardiac arrhythmias. To improve the success of this procedure, new approaches for real-time visualization of ablation sites are being developed. One of these promising methods is hyperspectral imaging, an approach that detects lesions based on changes in the endogenous tissue autofluorescence profile. To facilitate the clinical implementation of this approach, we examined the key variables that can influence ablation-induced spectral changes, including the drop in myocardial NADH levels, the release of lipofuscin-like pigments, and the increase in diffuse reflectance of the cardiac muscle beneath the endocardial layer. Insights from these experiments suggested simpler algorithms that can be used to acquire and post-process the spectral information required to reveal the lesion sites. Our study is relevant to a growing number of multilayered clinical targets to which spectral approaches are being applied.

scholarly journals Autofluorescence hyperspectral imaging of radiofrequency ablation lesions in porcine cardiac tissue

2016 ◽  
Vol 10 (8) ◽  
pp. 1008-1017 ◽  
Author(s):  
Daniel A. Gil ◽  
Luther M. Swift ◽  
Huda Asfour ◽  
Narine Muselimyan ◽  
Marco A. Mercader ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Hyperspectral Imaging ◽  
Cardiac Tissue

scholarly journals NADH as an Endogenous Marker of Cardiac Tissue Injury at the Site of Radiofrequency Ablation

2011 ◽  
Vol 100 (3) ◽  
pp. 439a
Author(s):  
Marco Mercader ◽  
Luther Swift ◽  
Huda Asfour ◽  
Matthew Kay ◽  
Narine Sarvazyan
Keyword(s):  
Radiofrequency Ablation ◽  
Cardiac Tissue ◽  
Tissue Injury

Computational Model of Radiofrequency Ablation of Cardiac Tissues Incorporating Thermo-Electro-Mechanical Interactions

2020 ◽  
Author(s):  
Sundeep Singh ◽  
Roderick Melnik
Keyword(s):  
Radiofrequency Ablation ◽  
Cardiac Tissue ◽  
A Priori Estimates ◽  
Ex Vivo ◽  
Numerical Study ◽  
Experimental Studies ◽  
Computational Modelling ◽  
Cardiac Ablation ◽  
Fully Coupled

Abstract The application of radiofrequency ablation (RFA) has been widely explored in treating various types of cardiac arrhythmias. Computational modelling provides a safe and viable alternative to ex vivo and in vivo experimental studies for quantifying the effects of different variables efficiently and reliably, apart from providing a priori estimates of the ablation volume attained during cardiac ablation procedures. In this contribution, we report a fully coupled thermo-electro-mechanical model for a more accurate prediction of the treatment outcomes during the radiofrequency cardiac ablation. A numerical model comprising of cardiac tissue and the cardiac chamber has been developed in which an electrode has been inserted perpendicular to the cardiac tissue to simulate actual clinical procedures. Temperature-dependent heat capacity, electrical and thermal conductivities, and blood perfusion rate have been considered to model more realistic scenarios. The effects of blood flow and contact force of the electrode tip on the efficacy of a fully coupled model of RFA have been systematically investigated. The numerical study predicts that the efficacy of RFA is significantly dependent on the thermo-electro-mechanical parameters of the cardiac tissue.

Cytopathology of Cardiac Tissue from Daunomycin-Treated Mice

1971 ◽  
Vol 29 ◽  
pp. 550-551
Author(s):  
Robert H. Liss ◽  
Frances A. Cotton
Keyword(s):  
Cardiac Tissue ◽  
Cardiac Toxicity ◽  
Drug Distribution ◽  
Personal Communication ◽  
Intravenous Dose ◽  
Single Intravenous Dose ◽  
Physiologic Saline ◽  
Histopathologic Changes ◽  
Distribution Studies ◽  
Lung And Kidney

Daunomycin, an antibiotic used in the clinical management of acute leukemia, produces a delayed, lethal cardiac toxicity. The lethality is dose and schedule dependent; histopathologic changes induced by the drug have been described in heart, lung, and kidney from hamsters in both single and multiple dose studies. Mice given a single intravenous dose of daunomycin (10 mg/kg) die 6-7 days later. Drug distribution studies indicate that the rodents excrete most of a single dose of the drug as daunomycin and metabolite within 48 hours after dosage (M. A. Asbell, personal communication).Myocardium from the ventricles of 6 moribund BDF1 mice which had received a single intravenous dose of daunomycin (10 mg/kg), and from controls dosed with physiologic saline, was fixed in glutaraldehyde and prepared for electron microscopy.

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