Whole heart histology a method for the direct integration of histology with electrophysiological and imaging data

Cardiolog

Mini-, micro-, and conventional electrodes an in vivo electrophysiology and ex vivo histology head-to-head comparison

OBJECTIVES This study sought to assess the relative effect of catheter, tissue, and catheter-tissue parameters, on the ability to determine the amount of viable myocardium in vivo.BACKGROUND Although multiple variables impact bipolar voltages (BVs), electrode size, interelectrode spacing, and directional dependency are of particular interest with the development of catheters incorporating mini and microelectrodes.METHODS Nine swine with early reperfusion myocardial infarctions were mapped using the QDot catheter and then remapped using a Pentaray catheter. All QDot points were matched with Pentaray points within 5 mm. The swine were sacrificed, and mapping data projected onto the heart. Transmural biopsies corresponding to mapping points were obtained, allowing a comparison of electrograms recorded by mini, micro-, and conventional electrodes with histology.RESULTS The conventional BV of 2,322 QDot points was 1.9 +/- 1.3 mV. The largest of the 3 microelectrode BVs (BV mu Max) average 4.8 +/- 3.1 mV. The difference between the largest (BV mu Max) and smallest (BV mu Min) at a given location was 53.7 +/- 18.1%. The relationships between both BV mu Max and BV mu Min and between the conventional BV and BV mu Max were positively related but with a significant spread in data, which was more pronounced for the latter. Pentaray points positively related to the BV mu Max with poor fit. On histology, increasing viable myocardium increased voltage, but both the slope coefficient and fit were best for BV mu Max.CONCLUSIONS Using histology, we could demonstrate that BV mu Max is superior to identify viable myocardium compared with BVC and BV using the Pentaray catheter. The ability to simultaneously record 3 BV(mu)s with different orientations, for the same beat, with controllable contact and selecting BV mu Max for local BV may partially compensate for wave front direction. (C) 2021 by the American College of Cardiology Foundation.Cardiolog

The population history of northeastern Siberia since the Pleistocene

FGW – Publications without University Leiden contractDescriptive and Comparative Linguistic

TESS discovery of a super-earth and three sub-neptunes hosted by the bright, sunlike star HD 108236

We report the discovery and validation of four extrasolar planets hosted by the nearby, bright, Sun-like (G3V) star HD 108236 using data from the Transiting Exoplanet Survey Satellite (TESS). We present transit photometry, reconnaissance, and precise Doppler spectroscopy, as well as high-resolution imaging, to validate the planetary nature of the objects transiting HD 108236, also known as the TESS Object of Interest (TOI) 1233. The innermost planet is a possibly rocky super-Earth with a period of 3.79523+0.00047-0.00044 days and has a radius of 1.586 ± 0.098 R⊗.The outer planets are sub-Neptunes, with potential gaseous envelopes, having radii of 2.068+0.10-0.091 R⊗, 2.72 ± 0.11 R⊗, and 3.12+0.13-0.12 R⊗ and periods of 6.20370+0.00064-0.00052 days, 14.17555+0.00099-0.0011 days, and 19.5917+0.0022-0.0020 days, respectively. With V and Ks magnitudes of 9.2 and 7.6, respectively, the bright host star makes the transiting planets favorable targets for mass measurements and, potentially, for atmospheric characterization via transmission spectroscopy. HD 108236 is the brightest Sun-like star in the visual (V ) band known to host four or more transiting exoplanets. The discovered planets span a broad range of planetary radii and equilibrium temperatures and share a common history of insolation from a Sun-like star (R∗ = 0.888 ± 0.017 R⊙, Teff = 5730 ± 50 K), making HD 108236 an exciting, opportune cosmic laboratory for testing models of planet formation and evolution

Multielectrode Unipolar Voltage Mapping and Electrogram Morphology to Identify Post-Infarct Scar Geometry Validation by Histology

OBJECTIVES This study sought to evaluate the ability of uni-and bipolar electrograms collected with a multielectrode catheter with smaller electrodes to: 1) delineate scar; and 2) determine local scar complexity.& nbsp;BACKGROUND Early reperfusion results in variable endocardial scar, often overlaid with surviving viable myocardium. Although bipolar voltage (BV) mapping is considered the pillar of substrate-based ablation, the role of unipolar voltage (UV) mapping has not been sufficiently explored. It has been suggested that bipolar electrograms collected with small electrode catheters can better identify complex scar geometries.& nbsp;METHODS Twelve swine with early reperfusion infarctions were mapped with the 48-electrode OctaRay catheter and a conventional catheter during sinus rhythm. BV electrograms with double components were identified. Transmural (n = 933) biopsy specimens corresponding to mapping points were obtained, histologically assessed, and classified by scar geometry.& nbsp;RESULTS OctaRay UV (UVOcta) and BV (BVOcta) amplitude were associated with the amount of viable myocardium at a given location, with a stronger association for UVOcta (R2 = 0.767 vs 0.473). Cutoff values of 3.7 mV and 1.0 mV could delineate scar (area under the curve: 0.803 and 0.728 for UVOcta and BVOcta, respectively). The morphology of bipolar electrograms collected with the OctaRay catheter more frequently identified areas with 2 layers of surviving myocardium than electrograms collected with the conventional catheter (84% vs 71%).& nbsp;CONCLUSIONS UV mapping can generate a map to delineate the area of interest when using a multielectrode catheter. Within this area of interest, the morphology of bipolar electrograms can identify areas in which a surviving epicardial layer may overlay a poorly coupled, potentially arrhythmogenic, endocardium. (C) 2022 by the American College of Cardiology Foundation.Cardiolog

Multielectrode Unipolar Voltage Mapping and Electrogram Morphology to Identify Post-Infarct Scar Geometry Validation by Histology

OBJECTIVES This study sought to evaluate the ability of uni-and bipolar electrograms collected with a multielectrode catheter with smaller electrodes to: 1) delineate scar; and 2) determine local scar complexity.& nbsp;BACKGROUND Early reperfusion results in variable endocardial scar, often overlaid with surviving viable myocardium. Although bipolar voltage (BV) mapping is considered the pillar of substrate-based ablation, the role of unipolar voltage (UV) mapping has not been sufficiently explored. It has been suggested that bipolar electrograms collected with small electrode catheters can better identify complex scar geometries.& nbsp;METHODS Twelve swine with early reperfusion infarctions were mapped with the 48-electrode OctaRay catheter and a conventional catheter during sinus rhythm. BV electrograms with double components were identified. Transmural (n = 933) biopsy specimens corresponding to mapping points were obtained, histologically assessed, and classified by scar geometry.& nbsp;RESULTS OctaRay UV (UVOcta) and BV (BVOcta) amplitude were associated with the amount of viable myocardium at a given location, with a stronger association for UVOcta (R2 = 0.767 vs 0.473). Cutoff values of 3.7 mV and 1.0 mV could delineate scar (area under the curve: 0.803 and 0.728 for UVOcta and BVOcta, respectively). The morphology of bipolar electrograms collected with the OctaRay catheter more frequently identified areas with 2 layers of surviving myocardium than electrograms collected with the conventional catheter (84% vs 71%).& nbsp;CONCLUSIONS UV mapping can generate a map to delineate the area of interest when using a multielectrode catheter. Within this area of interest, the morphology of bipolar electrograms can identify areas in which a surviving epicardial layer may overlay a poorly coupled, potentially arrhythmogenic, endocardium. (C) 2022 by the American College of Cardiology Foundation