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Intracardiac light catheter for rapid scanning transmural absorbance spectroscopy of perfused myocardium: measurement of myoglobin oxygenation and mitochondria redox state.
Am J Physiol Heart Circ Physiol 2017; 313(6):H1199-H1208AJ

Abstract

Absorbance spectroscopy of intrinsic cardiac chromophores provides nondestructive assessment of cytosolic oxygenation and mitochondria redox state. Isolated perfused heart spectroscopy is usually conducted by collecting reflected light from the heart surface, which represents a combination of surface scattering events and light that traversed portions of the myocardium. Reflectance spectroscopy with complex surface scattering effects in the beating heart leads to difficulty in quantitating chromophore absorbance. In this study, surface scattering was minimized and transmural path length optimized by placing a light source within the left ventricular chamber while monitoring transmurally transmitted light at the epicardial surface. The custom-designed intrachamber light catheter was a flexible coaxial cable (2.42-Fr) terminated with an encapsulated side-firing LED of 1.8 × 0.8 mm, altogether similar in size to a Millar pressure catheter. The LED catheter had minimal impact on aortic flow and heart rate in Langendorff perfusion and did not impact stability of the left ventricule of the working heart. Changes in transmural absorbance spectra were deconvoluted using a library of chromophore reference spectra to quantify the relative contribution of specific chromophores to the changes in measured absorbance. This broad-band spectral deconvolution approach eliminated errors that may result from simple dual-wavelength absorbance intensity. The myoglobin oxygenation level was only 82.2 ± 3.0%, whereas cytochrome c and cytochrome a + a3 were 13.3 ± 1.4% and 12.6 ± 2.2% reduced, respectively, in the Langendorff-perfused heart. The intracardiac illumination strategy permits transmural optical absorbance spectroscopy in perfused hearts, which provides a noninvasive real-time monitor of cytosolic oxygenation and mitochondria redox state.NEW & NOTEWORTHY Here, a novel nondestructive real-time approach for monitoring intrinsic indicators of cardiac metabolism and oxygenation is described using a catheter-based transillumination of the left ventricular free wall together with complete spectral analysis of transmitted light. This approach is a significant improvement in the quality of cardiac optical absorbance spectroscopic metabolic analyses.

Authors+Show Affiliations

Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland; and. Department of Biomedical Engineering, The George Washington University, Washington, District of Columbia.Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland; and. Department of Biomedical Engineering, The George Washington University, Washington, District of Columbia.Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland; and.Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland; and.Department of Biomedical Engineering, The George Washington University, Washington, District of Columbia.Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland; and balabanr@nhlbi.nih.gov.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

28939647

Citation

Femnou, Armel N., et al. "Intracardiac Light Catheter for Rapid Scanning Transmural Absorbance Spectroscopy of Perfused Myocardium: Measurement of Myoglobin Oxygenation and Mitochondria Redox State." American Journal of Physiology. Heart and Circulatory Physiology, vol. 313, no. 6, 2017, pp. H1199-H1208.
Femnou AN, Kuzmiak-Glancy S, Covian R, et al. Intracardiac light catheter for rapid scanning transmural absorbance spectroscopy of perfused myocardium: measurement of myoglobin oxygenation and mitochondria redox state. Am J Physiol Heart Circ Physiol. 2017;313(6):H1199-H1208.
Femnou, A. N., Kuzmiak-Glancy, S., Covian, R., Giles, A. V., Kay, M. W., & Balaban, R. S. (2017). Intracardiac light catheter for rapid scanning transmural absorbance spectroscopy of perfused myocardium: measurement of myoglobin oxygenation and mitochondria redox state. American Journal of Physiology. Heart and Circulatory Physiology, 313(6), pp. H1199-H1208. doi:10.1152/ajpheart.00306.2017.
Femnou AN, et al. Intracardiac Light Catheter for Rapid Scanning Transmural Absorbance Spectroscopy of Perfused Myocardium: Measurement of Myoglobin Oxygenation and Mitochondria Redox State. Am J Physiol Heart Circ Physiol. 2017 Dec 1;313(6):H1199-H1208. PubMed PMID: 28939647.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Intracardiac light catheter for rapid scanning transmural absorbance spectroscopy of perfused myocardium: measurement of myoglobin oxygenation and mitochondria redox state. AU - Femnou,Armel N, AU - Kuzmiak-Glancy,Sarah, AU - Covian,Raul, AU - Giles,Abigail V, AU - Kay,Matthew W, AU - Balaban,Robert S, Y1 - 2017/09/22/ PY - 2017/06/05/received PY - 2017/09/05/revised PY - 2017/09/19/accepted PY - 2017/9/25/pubmed PY - 2017/12/13/medline PY - 2017/9/24/entrez KW - Langendorff heart KW - broad-band spectral analysis KW - cytochromes KW - mitochondria SP - H1199 EP - H1208 JF - American journal of physiology. Heart and circulatory physiology JO - Am. J. Physiol. Heart Circ. Physiol. VL - 313 IS - 6 N2 - Absorbance spectroscopy of intrinsic cardiac chromophores provides nondestructive assessment of cytosolic oxygenation and mitochondria redox state. Isolated perfused heart spectroscopy is usually conducted by collecting reflected light from the heart surface, which represents a combination of surface scattering events and light that traversed portions of the myocardium. Reflectance spectroscopy with complex surface scattering effects in the beating heart leads to difficulty in quantitating chromophore absorbance. In this study, surface scattering was minimized and transmural path length optimized by placing a light source within the left ventricular chamber while monitoring transmurally transmitted light at the epicardial surface. The custom-designed intrachamber light catheter was a flexible coaxial cable (2.42-Fr) terminated with an encapsulated side-firing LED of 1.8 × 0.8 mm, altogether similar in size to a Millar pressure catheter. The LED catheter had minimal impact on aortic flow and heart rate in Langendorff perfusion and did not impact stability of the left ventricule of the working heart. Changes in transmural absorbance spectra were deconvoluted using a library of chromophore reference spectra to quantify the relative contribution of specific chromophores to the changes in measured absorbance. This broad-band spectral deconvolution approach eliminated errors that may result from simple dual-wavelength absorbance intensity. The myoglobin oxygenation level was only 82.2 ± 3.0%, whereas cytochrome c and cytochrome a + a3 were 13.3 ± 1.4% and 12.6 ± 2.2% reduced, respectively, in the Langendorff-perfused heart. The intracardiac illumination strategy permits transmural optical absorbance spectroscopy in perfused hearts, which provides a noninvasive real-time monitor of cytosolic oxygenation and mitochondria redox state.NEW & NOTEWORTHY Here, a novel nondestructive real-time approach for monitoring intrinsic indicators of cardiac metabolism and oxygenation is described using a catheter-based transillumination of the left ventricular free wall together with complete spectral analysis of transmitted light. This approach is a significant improvement in the quality of cardiac optical absorbance spectroscopic metabolic analyses. SN - 1522-1539 UR - https://www.unboundmedicine.com/medline/citation/28939647/Intracardiac_light_catheter_for_rapid_scanning_transmural_absorbance_spectroscopy_of_perfused_myocardium:_measurement_of_myoglobin_oxygenation_and_mitochondria_redox_state_ L2 - http://www.physiology.org/doi/full/10.1152/ajpheart.00306.2017?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -