Search results for "optical mapping"
showing 10 items of 10 documents
Nerves projecting from the intrinsic cardiac ganglia of the pulmonary veins modulate sinoatrial node pacemaker function
2013
Rationale: Autonomic nerves from sinoatrial node (SAN) ganglia are known to regulate SAN function. However, it is unclear whether remote pulmonary vein ganglia (PVG) also modulate SAN pacemaker rhythm. Objective: To investigate whether in the mouse heart PVG modulate SAN function. Methods and Results: In hearts from 45 C57BL and 7 Connexin40+/GFP mice, we used tyrosine-hydroxylase (TH) and choline-acetyltransferase (ChAT) immunofluorescence labeling to characterize adrenergic and cholinergic elements, repectively, within the PVG and SAN. PVG project postganglionic nerves to the SAN. TH and ChAT stained nerves, enter the SAN as an extensive, dense mesh-like neural network. Neurons in PVG are…
Comparison of Intensity-based B-splines and Point-to-Pixel Tracking Techniques for Motion Reduction in Optical Mapping
2016
Suppression of motion artifacts (MA) in cardiac optical mapping usually requires uncoupling of cardiac contraction by restriction techniques, which are known to have important effects on cardiac physiology deteriorating the quality of acquisitions and their interpretation. In this study, we propose to assess the performance of two independent intensity-based post-processing strategies to minimize MAs during registration. A point-to-pixel block-matching classical similarity-based tracking with displacement interpolation is compared to a well-known non-rigid registration algorithm where the deformation field is obtained using cubic splines. Both strategies were tested on synthetic and real op…
Integration of different cardiac electrophysiological models into a single simulation pipeline
2012
Clinical translation of computational models of the heart has been hampered by the absence of complete and rigorous technical and clinical validation, as well as benchmarking of the developed tools. To address this issue, a dataset containing the cardiac anatomy and fibre orientations from magnetic resonance images (MRI), as well as epicardial transmembrane potentials from optical mapping acquired on ex-vivo porcine hearts, have previously been made available to the community. Image processing techniques were developed to integrate MRI images with electrical information. Different models were tested and compared with the integrated data1, including: i) a new methodology to customize and reg…
Simultaneous atrial and ventricular restitution and fibrillation analyses using a low-cost scalable panoramic whole-heart optical mapping configurati…
2021
Abstract Introduction Optical mapping (OM) is the primary method for imaging electrophysiologically relevant parameters from the outer surface of Langendorff-perfused hearts. However, current panoramic OM systems are financially challenging, require multiple sensors to map wide areas of the surface with overlapping regions and missing areas of interest due to the intrinsic shape of the heart. We proposed different panoramic configurations to dynamically characterize atrial and ventricular function during arrhythmia and, in presence of a coronary occlusion. Methods We devised both a multi-sensor and a single sensor system integrated with the perfusion circuit comprising sensor elements, a co…
Personalization of Fast Conduction Purkinje System in Eikonal-Based Electrophysiological Models with Optical Mapping Data
2010
We present a pipeline for the personalization of model-based Purkinje fast conduction system using fast electrophysiological models and optical mapping data acquired from ex-vivo porcine hearts. The regional density of the Purkinje terminals as well as the latest endocardial activation time were the parameters personalized in an iterative procedure maximizing the similarity between the outcome of the electrophysiological simulations and measurements obtained from optical mapping data. We used a fast wave-front Eikonal-based electrophysiological model that generated the depolarization time maps that were subsequently compared with measurements at each iteration of the optimization stage. The…
Inter-Model Consistency and Complementarity: Learning from ex-vivo Imaging and Electrophysiological Data towards an Integrated Understanding of Cardi…
2011
International audience; Computational models of the heart at various scales and levels of complexity have been independently developed, parameterised and validated using a wide range of experimental data for over four decades. However, despite remarkable progress, the lack of coordinated efforts to compare and combine these computational models has limited their impact on the numerous open questions in cardiac physiology. To address this issue, a comprehensive dataset has previously been made available to the community that contains the cardiac anatomy and fibre orientations from magnetic resonance imaging as well as epicardial transmembrane potentials from optical mapping measured on a per…
Ranolazine-Mediated Attenuation of Mechanoelectric Feedback in Atrial Myocyte Monolayers.
2020
[EN] Background Mechanical stretch increases Na(+)inflow into myocytes, related to mechanisms including stretch-activated channels or Na+/H(+)exchanger activation, involving Ca(2+)increase that leads to changes in electrophysiological properties favoring arrhythmia induction. Ranolazine is an antianginal drug with confirmed beneficial effects against cardiac arrhythmias associated with the augmentation ofI(NaL)current and Ca(2+)overload. Objective This study investigates the effects of mechanical stretch on activation patterns in atrial cell monolayers and its pharmacological response to ranolazine. Methods Confluent HL-1 cells were cultured in silicone membrane plates and were stretched to…
A Single-sensor High-resolution Panoramic Optical Mapping Configuration for Simultaneous Non-overlapped Complete Atrial and Ventricular Parametric Im…
2017
Nowadays optical mapping (OM) is the primary method for imaging electrophysiologically relevant parameters from the outer surface of Langendorff-perfused hearts. This technique has become essential for comprehensively understanding mechanisms of cardiac propagation during physiological activation, arrhythmia, and therapeutic antiarrhythmic interventions in translational hearts. Panoramic whole heart optical mapping systems, using either multiple cameras, plane mirrors or a combination of both, have been developed to overcome intrinsic visualization limitations to traditional single-sensor designs. However current panoramic OM systems are financially challenging for physiology and engineerin…
Low-Cost Optical Mapping Systems for Panoramic Imaging of Complex Arrhythmias and Drug-Action in Translational Heart Models.
2017
[EN] Panoramic optical mapping is the primary method for imaging electrophysiological activity from the entire outer surface of Langendorff-perfused hearts. To date, it is the only method of simultaneously measuring multiple key electrophysiological parameters, such as transmembrane voltage and intracellular free calcium, at high spatial and temporal resolution. Despite the impact it has already had on the fields of cardiac arrhythmias and whole-heart computational modeling, present-day system designs precludes its adoption by the broader cardiovascular research community because of their high costs. Taking advantage of recent technological advances, we developed and validated low-cost opti…