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Hardison E, Cox ZL, Heckman K, Kelly PA, Lindenfeld J. A case report of ivabradine used for heart rate control of atrial fibrillation in acute decompensated heart failure. Eur Heart J Case Rep 2022; 6:ytac077. [PMID: 35233502 PMCID: PMC8877172 DOI: 10.1093/ehjcr/ytac077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/06/2021] [Accepted: 02/09/2022] [Indexed: 11/20/2022]
Abstract
Background Achieving pharmacologic rate control in patients with atrial fibrillation (AF) with rapid ventricular response (RVR) can be tricky when the patient’s underlying cardiac function is decreased. We present a case illustrating how ivabradine can be useful in this clinical scenario. Case summary A 95-year-old woman with a history of systolic heart failure (HF) presented with acute decompensated HF in AF with RVR. Beta blockade and calcium channel blockade were avoided given her cardiac history, and diuresis with high doses of furosemide was ineffective. Her ventricular response slowed with ivabradine, allowing for rapid decongestion and a safe discharge home. Discussion Ivabradine acts on the If current of cardiac pacemaker cells to slow heart rate (HR), and it currently carries a class IIa recommendation to reduce the risk of HF hospitalization and cardiac death in patients with left ventricular ejection fraction ≤35% and a symptomatic HR ≥70 b.p.m. Although current recommendations are for patients in sinus rhythm, ivabradine has a theoretical benefit in patients with AF given its mechanism of action. Because it does not negatively affect inotropy or blood pressure, ivabradine was used in our patient with a good clinical outcome. Our case provides an example of ivabradine’s usefulness in patients with AF in RVR with a history of depressed systolic function.
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Affiliation(s)
- Edward Hardison
- Department of Internal Medicine and Pediatrics, Vanderbilt University Medical Center and Monroe Carrell Jr. Children’s Hospital at Vanderbilt, One Hundred Oaks, 719 Thompson Ln, Suite 20400, Nashville, TN 37204, USA
| | - Zachary L Cox
- Department of Pharmacy, Lipscomb University College of Pharmacy, 1 University Park Dr, Nashville, TN 37204, USA
| | - Katherine Heckman
- Department of Internal Medicine, Vanderbilt University Medical Center, 1161 21st Ave S, Nashville, TN 37232, USA
| | - Patricia A Kelly
- Missoula Cardiology, 2419 Mullan Road, Suite A, Missoula, MT 59808, USA
| | - JoAnn Lindenfeld
- Department of Cardiovascular Medicine, Vanderbilt University Medical Center, 1161 21st Ave S, Nashville, TN 37232, USA
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Heckman K, Hicks Pries CE, Lawrence CR, Rasmussen C, Crow SE, Hoyt AM, von Fromm SF, Shi Z, Stoner S, McGrath C, Beem-Miller J, Berhe AA, Blankinship JC, Keiluweit M, Marín-Spiotta E, Monroe JG, Plante AF, Schimel J, Sierra CA, Thompson A, Wagai R. Beyond bulk: Density fractions explain heterogeneity in global soil carbon abundance and persistence. Glob Chang Biol 2022; 28:1178-1196. [PMID: 34862692 DOI: 10.1111/gcb.16023] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/02/2021] [Accepted: 11/02/2021] [Indexed: 06/13/2023]
Abstract
Understanding the controls on the amount and persistence of soil organic carbon (C) is essential for predicting its sensitivity to global change. The response may depend on whether C is unprotected, isolated within aggregates, or protected from decomposition by mineral associations. Here, we present a global synthesis of the relative influence of environmental factors on soil organic C partitioning among pools, abundance in each pool (mg C g-1 soil), and persistence (as approximated by radiocarbon abundance) in relatively unprotected particulate and protected mineral-bound pools. We show that C within particulate and mineral-associated pools consistently differed from one another in degree of persistence and relationship to environmental factors. Soil depth was the best predictor of C abundance and persistence, though it accounted for more variance in persistence. Persistence of all C pools decreased with increasing mean annual temperature (MAT) throughout the soil profile, whereas persistence increased with increasing wetness index (MAP/PET) in subsurface soils (30-176 cm). The relationship of C abundance (mg C g-1 soil) to climate varied among pools and with depth. Mineral-associated C in surface soils (<30 cm) increased more strongly with increasing wetness index than the free particulate C, but both pools showed attenuated responses to the wetness index at depth. Overall, these relationships suggest a strong influence of climate on soil C properties, and a potential loss of soil C from protected pools in areas with decreasing wetness. Relative persistence and abundance of C pools varied significantly among land cover types and soil parent material lithologies. This variability in each pool's relationship to environmental factors suggests that not all soil organic C is equally vulnerable to global change. Therefore, projections of future soil organic C based on patterns and responses of bulk soil organic C may be misleading.
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Affiliation(s)
- Katherine Heckman
- USDA Forest Service, Northern Research Station, Houghton, Michigan, USA
| | | | - Corey R Lawrence
- U.S. Geological Survey, Geosciences and Environmental Change Science Center, Denver, Colorado, USA
| | - Craig Rasmussen
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
| | - Susan E Crow
- Natural Resources and Environmental Management Department, University of Hawaii Manoa, Honolulu, Hawaii, USA
| | - Alison M Hoyt
- Department of Biogeochemical Processes, Max-Planck-Institute for Biogeochemistry, Jena, Germany
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Sophie F von Fromm
- Department of Biogeochemical Processes, Max-Planck-Institute for Biogeochemistry, Jena, Germany
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Zheng Shi
- Computational Sciences & Engineering Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Shane Stoner
- Department of Biogeochemical Processes, Max-Planck-Institute for Biogeochemistry, Jena, Germany
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Casey McGrath
- Natural Resources and Environmental Management Department, University of Hawaii Manoa, Honolulu, Hawaii, USA
| | - Jeffrey Beem-Miller
- Department of Biogeochemical Processes, Max-Planck-Institute for Biogeochemistry, Jena, Germany
| | - Asmeret Asefaw Berhe
- Department of Life and Environmental Sciences, University of California, Merced, California, USA
| | - Joseph C Blankinship
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
| | - Marco Keiluweit
- School of Earth & Sustainability and Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
| | - Erika Marín-Spiotta
- Department of Geography, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - J Grey Monroe
- Department of Plant Sciences, University of California, Davis, Davis, California, USA
| | - Alain F Plante
- Department of Earth & Environmental Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Joshua Schimel
- Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California, USA
| | - Carlos A Sierra
- Department of Biogeochemical Processes, Max-Planck-Institute for Biogeochemistry, Jena, Germany
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Aaron Thompson
- Department of Crop and Soil Sciences and the Odum School of Ecology, University of Georgia, Athens, Georgia, USA
| | - Rota Wagai
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
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Fernandez CW, Heckman K, Kolka R, Kennedy PG. Melanin mitigates the accelerated decay of mycorrhizal necromass with peatland warming. Ecol Lett 2019; 22:498-505. [DOI: 10.1111/ele.13209] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/24/2018] [Accepted: 11/08/2018] [Indexed: 01/24/2023]
Affiliation(s)
| | | | - Randall Kolka
- USDA Forest Service Northern Research Station, Grand Rapids, MN USA
| | - Peter G. Kennedy
- Department of Plant & Microbial Biology University of Minnesota St. Paul MN USA
- Department of Ecology, Evolution, and Behavior St. Paul MN USA
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Kinney KM, Asner GP, Cordell S, Chadwick OA, Heckman K, Hotchkiss S, Jeraj M, Kennedy-Bowdoin T, Knapp DE, Questad EJ, Thaxton JM, Trusdell F, Kellner JR. Primary Succession on a Hawaiian Dryland Chronosequence. PLoS One 2015; 10:e0123995. [PMID: 26066334 PMCID: PMC4467043 DOI: 10.1371/journal.pone.0123995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 02/25/2015] [Indexed: 12/03/2022] Open
Abstract
We used measurements from airborne imaging spectroscopy and LiDAR to quantify the biophysical structure and composition of vegetation on a dryland substrate age gradient in Hawaii. Both vertical stature and species composition changed during primary succession, and reveal a progressive increase in vertical stature on younger substrates followed by a collapse on Pleistocene-aged flows. Tall-stature Metrosideros polymorpha woodlands dominated on the youngest substrates (hundreds of years), and were replaced by the tall-stature endemic tree species Myoporum sandwicense and Sophora chrysophylla on intermediate-aged flows (thousands of years). The oldest substrates (tens of thousands of years) were dominated by the short-stature native shrub Dodonaea viscosa and endemic grass Eragrostis atropioides. We excavated 18 macroscopic charcoal fragments from Pleistocene-aged substrates. Mean radiocarbon age was 2,002 years and ranged from < 200 to 7,730. Genus identities from four fragments indicate that Osteomeles spp. or M. polymorpha once occupied the Pleistocene-aged substrates, but neither of these species is found there today. These findings indicate the existence of fires before humans are known to have occupied the Hawaiian archipelago, and demonstrate that a collapse in vertical stature is prevalent on the oldest substrates. This work contributes to our understanding of prehistoric fires in shaping the trajectory of primary succession in Hawaiian drylands.
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Affiliation(s)
- Kealohanuiopuna M. Kinney
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America
- Institute of Pacific Islands Forestry, United States Department of Agriculture Forest Service, Hilo, Hawaii, United States of America
- * E-mail:
| | - Gregory P. Asner
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, United States of America
| | - Susan Cordell
- Institute of Pacific Islands Forestry, United States Department of Agriculture Forest Service, Hilo, Hawaii, United States of America
| | - Oliver A. Chadwick
- Department of Geography, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Katherine Heckman
- United States Department of Agriculture, Forest Service, Northern Research Station, Center for Accelerator Mass Spectrometry–Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Sara Hotchkiss
- Department of Botany, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Marjeta Jeraj
- Department of Botany, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Ty Kennedy-Bowdoin
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, United States of America
| | - David E. Knapp
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California, United States of America
| | - Erin J. Questad
- Department of Biological Sciences, California Polytechnic University, Pomona, California, United States of America
| | - Jarrod M. Thaxton
- Department of Biological Sciences, Eastern Kentucky University, Richmond, Kentucky, United States of America
| | - Frank Trusdell
- United States Geological Survey, Hawaii Volcano Observatory, Volcano, Hawaii, United States of America
| | - James R. Kellner
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America
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Millar CI, Heckman K, Swanston C, Schmidt K, Westfall RD, Delany DL. Radiocarbon dating of American pika fecal pellets provides insights into population extirpations and climate refugia. Ecol Appl 2014; 24:1748-1768. [PMID: 29210235 DOI: 10.1890/13-0520.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The American pika (Ochotona princeps) has become a species of concern for its sensitivity to warm temperatures and potential vulnerability to global warming. We explored the value of radiocarbon dating of fecal pellets to address questions of population persistence and timing of site extirpation. Carbon was extracted from pellets collected at 43 locations in the western Great Basin, USA, including three known occupied sites and 40 sites of uncertain status at range margins or where previous studies indicated the species is vulnerable. We resolved calibrated dates with high precision (within several years), most of which fell in the period of the mid-late 20th century bomb curve. The two-sided nature of the bomb curve renders far- and near-side dates of equal probability, which are separated by one to four decades. We document methods for narrowing resolution to one age range, including stratigraphic analysis of vegetation collected from pika haypiles. No evidence was found for biases in atmospheric 14C levels due to fossil-derived or industrial CO2 contamination. Radiocarbon dating indicated that pellets can persist for >59 years; known occupied sites resolved contemporary dates. Using combined evidence from field observations and radiocarbon dating, and the Bodie Mountains as an example, we propose a historical biogeographic scenario for pikas in minor Great Basin mountain ranges adjacent to major cordillera, wherein historical climate variability led to cycles of extirpation and recolonization during alternating cool and warm centuries. Using this model to inform future dynamics for small ranges in biogeographic settings similar to the Bodie Mountains in California, extirpation of pikas appears highly likely under directional warming trends projected for the next century, even while populations in extensive cordillera (e.g., Sierra Nevada, Rocky Mountains, Cascade Range) are likely to remain viable due to extensive, diverse habitat and high connectivity.
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Margalit DN, Heckman K, Chen Y, Catalano PJ, Vivenzio T, Nissen K, Mauch P, Ng AK. Technologic advancements and error rates in radiation therapy (RT) delivery. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.6141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Cabezudo I, Pfaller M, Gerarden T, Koontz F, Wenzel R, Gingrich R, Heckman K, Burns CP. Value of the Cand-Tec Candida antigen assay in the diagnosis and therapy of systemic candidiasis in high-risk patients. Eur J Clin Microbiol Infect Dis 1989; 8:770-7. [PMID: 2512147 DOI: 10.1007/bf02185843] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A total of 911 sera from 171 patients at risk for systemic candidiasis and 24 sera from 24 non-hospitalized control subjects were analyzed for the presence of candida antigen using a commercially available latex agglutination test (Cand-Tec). Thirty-seven (22%) patients had systemic candidiasis documented by positive blood cultures, deep biopsy culture and histopathology or autopsy. Six patients had transient candidemia, 20 patients had candiduria, 53 patients had mucous membrane colonization, 21 patients were not colonized but received empiric amphotericin B, and 34 patients were not colonized and not treated with amphotericin B. The intraobserver reproducibility was 90% for the exact titer and 100% for a deviation of one dilution. The sensitivity and specificity of the candida antigen test in detection of systemic candidiasis was 95% and 50% (greater than or equal to 1:2), 73% and 72% (greater than or equal to 1:4), and 46% and 80% (greater than or equal to 1:8) respectively. Despite the poor specificity, serial antigen determinations in patients with documented systemic candidiasis demonstrated both an early diagnostic and prognostic role for the candida antigen test. Seventy-one percent of patients whose antigen titer increased during the course of amphotericin B therapy of documented infection died versus only 13% of those whose titer decreased while on therapy (p = 0.01). The candida antigen test has a limited yet potentially useful role in the diagnosis and management of systemic candidiasis in high-risk patients.
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Affiliation(s)
- I Cabezudo
- Veterans Administration Medical Center, Iowa City, Iowa 52240
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