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<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="editorial" dtd-version="1.1" specific-use="sps-1.9" xml:lang="en">
  <front>
    <journal-meta>
      <journal-id journal-id-type="nlm-ta">Arq Bras Cardiol</journal-id>
      <journal-id journal-id-type="publisher-id">abc</journal-id>
      <journal-title-group>
        <journal-title>Arquivos Brasileiros de Cardiologia</journal-title>
        <abbrev-journal-title abbrev-type="publisher">Arq. Bras. Cardiol.</abbrev-journal-title>
      </journal-title-group>
      <issn pub-type="ppub">0066-782X</issn>
      <issn pub-type="epub">1678-4170</issn>
      <publisher>
        <publisher-name>Sociedade Brasileira de Cardiologia - SBC</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v3">QchPzn8SycgHCsGcCQGtRNS</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v2">S0066-782X2019000600747</article-id>
      <article-id pub-id-type="doi">10.5935/abc.20190097</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Short Editorial</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Heart and Skeletal Muscles: Linked by Autonomic Nervous System</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0001-6679-6695</contrib-id>
          <name>
            <surname>Araujo</surname>
            <given-names>Claudio Gil</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="corresp" rid="c1"/>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0002-3738-1586</contrib-id>
          <name>
            <surname>Laukkanen</surname>
            <given-names>Jari Antero</given-names>
          </name>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
      </contrib-group>
      <aff id="aff1">
        <label>1</label>
        <institution content-type="orgname">Exercise Medicine Clinic</institution>
        <addr-line>
          <city>Rio de Janeiro</city>
          <state>RJ</state>
        </addr-line>
        <country country="BR">Brazil</country>
        <institution content-type="original">Exercise Medicine Clinic - CLINIMEX, Rio de Janeiro, RJ - Brazil</institution>
      </aff>
      <aff id="aff2">
        <label>2</label>
        <institution content-type="orgname">University of Jyvaskyla</institution>
        <institution content-type="orgdiv1">Faculty of Sport and Health Sciences</institution>
        <addr-line>
          <city>Jyvaskyla</city>
        </addr-line>
        <country country="FI">Finland</country>
        <institution content-type="original">University of Jyvaskyla - Faculty of Sport and Health Sciences, Jyvaskyla - Finland</institution>
      </aff>
      <author-notes>
        <corresp id="c1"><bold>Mailing Address: Claudio Gil Araujo,</bold> Rua Siqueira Campos, 93/101-103, Postal Code 22031-072, Rio de Janeiro, RJ - Brazil. E-mail: <email>cgaraujo@iis.com.br</email>
				</corresp>
      </author-notes>
      <pub-date date-type="pub" publication-format="electronic">
        <day>15</day>
        <month>07</month>
        <year>2019</year>
      </pub-date>
      <pub-date date-type="collection" publication-format="electronic">
        <month>06</month>
        <year>2019</year>
      </pub-date>
      <volume>112</volume>
      <issue>6</issue>
      <fpage>747</fpage>
      <lpage>748</lpage>
      <permissions>
        <license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by/4.0/" xml:lang="en">
          <license-p>This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited</license-p>
        </license>
      </permissions>
      <kwd-group xml:lang="en">
        <title>Keywords</title>
        <kwd>Heart Failure</kwd>
        <kwd>Myocardium</kwd>
        <kwd>Muscle,Skeletal</kwd>
        <kwd>Autonomic Nervous System</kwd>
        <kwd>Homeostasis</kwd>
        <kwd>Sarcopenia</kwd>
        <kwd>Sympathetica Nervous System</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <p>The autonomic nervous system (ANS) plays a fundamental role in maintaining cell homeostasis and human life. The functionality of the heart and skeletal muscles is partially modulated by sympathetic and parasympathetic branches of the ANS both in resting and exercising conditions.</p>
    <p>Substantial literature attests to the fact that objective indices of muscle strength reflect health status. It is well-established that heart failure is typically accompanied by skeletal muscle abnormalities that contributed to the exercise intolerance and poor health-related quality of life usually seen in these patients.<xref ref-type="bibr" rid="B1">1</xref><sup>,</sup><xref ref-type="bibr" rid="B2">2</xref> Indeed, while a decrease in muscle mass and strength is naturally seen with ageing, especially after the fifth decade of life, this is especially more relevant in middle-aged and older patients with heart failure.</p>
    <p>Several decades ago, the term sarcopenia was proposed as a medical expression to describe the universal and involuntary loss in muscle mass that occurs with age.<xref ref-type="bibr" rid="B3">3</xref> However, despite the fact that several criteria were proposed to characterize it, a growing body of knowledge understanding its pathophysiology and confirming its clinical and epidemiological relevance and being listed in ICD-10,<xref ref-type="bibr" rid="B4">4</xref> still today, it remains rarely evaluated in daily medical practice.</p>
    <p>In a Brazilian and German collaborative research study, Fonseca et al.<xref ref-type="bibr" rid="B5">5</xref> analyzed data from 116 male patients with heart failure with reduced ejection fraction (HFrEF) that were submitted to a maximal cycling cardiopulmonary exercise testing using a ramp protocol. In addition, using a microneurography technique, muscle sympathetic nerve activity was directly recorded from the peroneal nerve and parasympathetic activity was estimated by the magnitude of heart rate decay in the first two minutes after the maximal cycling exercise test. Measurements were obtained from dual-energy X-ray absorptiometry (DEXA) and handgrip strength to reflect, respectively, body composition and muscle strength. Based on these measurements and applying standard literature criteria, the authors were able to identify the presence or absence of sarcopenia in their set of patients. We acknowledge the authors by their study originality that could add a significant contribution to the existing body of knowledge in the research area.</p>
    <p>Combining all these data, they searched for a link between heart-skeletal muscle abnormalities and ANS dysfunction and tried to quantify the association between sympathetic ANS abnormalities and sarcopenia in male patients with clinically stable heart failure. They have identified sarcopenia in 33 (28%) of HFrEF patients and their results indicated that these patients had significantly distinct results to the ANS variables assessed when compared as to the group of patients without sarcopenia.<xref ref-type="bibr" rid="B5">5</xref> Moreover, they found a significant although quite modest correlation (r = -0.29) between appendicular muscle mass and muscle sympathetic nerve activity. Looking in more details their results, it is possible to note that there is a considerable overlapping between the results of HFrEF patients with and without sarcopenia, which may diminish the clinical value.</p>
    <p>Based on their current study by Fonseca et al.,<xref ref-type="bibr" rid="B5">5</xref> we can speculate that if they have used other assessment methods, like the 4-second exercise test,<xref ref-type="bibr" rid="B6">6</xref><sup>,</sup><xref ref-type="bibr" rid="B7">7</xref> - a very specific one for assessing cardiac vagal activity - and handgrip strength relative to body weight or maximal muscle power<xref ref-type="bibr" rid="B8">8</xref> or even a simple functional test like the sitting-rising test,<xref ref-type="bibr" rid="B9">9</xref> all of them, more specific to assess dynapenia, a likely clinically more relevant issue than sarcopenia,<xref ref-type="bibr" rid="B10">10</xref><sup>,</sup><xref ref-type="bibr" rid="B11">11</xref> they could have found additional discriminative values.</p>
    <p>Finally, perhaps regular exercise/physical exercise could be the way to improve the health status of HFpEF patients. In acknowledging that this study showed an association between cardiac ANS dysfunction and heart and skeletal muscle abnormalities and knowing that regular aerobic and resistance exercise improves cardiac ANS modulation, including reducing the risk of ventricular fibrillation on the occurrence of a myocardial infarction,<xref ref-type="bibr" rid="B12">12</xref> and are strongly recommended as part of the medical treatment of patients with sarcopenia and for those with HFpEF;<xref ref-type="bibr" rid="B13">13</xref> it is quite motivating to think about an expected next step in research: a randomized controlled trial with exercise training intervention. Such study would assess if the ANS dysfunction reported by Fonseca et al.<xref ref-type="bibr" rid="B5">5</xref> is subject to reversal, and if so, how this would improve quality of life and other major health outcomes in patients with HFpEF.</p>
  </body>
  <back>
    <fn-group>
      <fn fn-type="other">
        <p>Short Editorial related to the article: Sympatho-Vagal Imbalance is Associated with Sarcopenia in Male Patients with Heart Failure</p>
      </fn>
    </fn-group>
    <ref-list>
      <title>References</title>
      <ref id="B1">
        <label>1</label>
        <mixed-citation>1 Engel PJ. Effort intolerance in chronic heart failure: what are we treating? J Am Coll Cardiol. 1990;15(5):995-8.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Engel</surname>
              <given-names>PJ</given-names>
            </name>
          </person-group>
          <article-title>Effort intolerance in chronic heart failure: what are we treating?</article-title>
          <source>J Am Coll Cardiol</source>
          <year>1990</year>
          <volume>15</volume>
          <issue>5</issue>
          <fpage>995</fpage>
          <lpage>998</lpage>
        </element-citation>
      </ref>
      <ref id="B2">
        <label>2</label>
        <mixed-citation>2 Pugliese NR, Fabiani I, Santini C, Rovai I, Pedrinelli R, Natali A, et al. Value of combined cardiopulmonary and echocardiography stress test to characterize the haemodynamic and metabolic responses of patients with heart failure and mid-range ejection fraction. Eur Heart J Cardiovasc Imaging. Feb 11 2019. [Epub ahead of print]. doi: 10.1093/ehjci/jez014</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Pugliese</surname>
              <given-names>NR</given-names>
            </name>
            <name>
              <surname>Fabiani</surname>
              <given-names>I</given-names>
            </name>
            <name>
              <surname>Santini</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Rovai</surname>
              <given-names>I</given-names>
            </name>
            <name>
              <surname>Pedrinelli</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Natali</surname>
              <given-names>A</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Value of combined cardiopulmonary and echocardiography stress test to characterize the haemodynamic and metabolic responses of patients with heart failure and mid-range ejection fraction</article-title>
          <source>Eur Heart J Cardiovasc Imaging</source>
          <day>11</day>
          <month>02</month>
          <year>2019</year>
          <comment>Epub ahead of print</comment>
          <pub-id pub-id-type="doi">10.1093/ehjci/jez014</pub-id>
        </element-citation>
      </ref>
      <ref id="B3">
        <label>3</label>
        <mixed-citation>3 Evans WJ, Campbell WW. Sarcopenia and age-related changes in body composition and functional capacity. J Nutr. 1993;123(2 Suppl):465-8.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Evans</surname>
              <given-names>WJ</given-names>
            </name>
            <name>
              <surname>Campbell</surname>
              <given-names>WW</given-names>
            </name>
          </person-group>
          <article-title>Sarcopenia and age-related changes in body composition and functional capacity</article-title>
          <source>J Nutr</source>
          <year>1993</year>
          <volume>123</volume>
          <issue>2 Suppl</issue>
          <fpage>465</fpage>
          <lpage>468</lpage>
        </element-citation>
      </ref>
      <ref id="B4">
        <label>4</label>
        <mixed-citation>4 Anker SD, Morley JE, von Haehling S. Welcome to the ICD-10 code for sarcopenia. J Cachexia Sarcopenia Muscle. 2016;7(5):512-4.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Anker</surname>
              <given-names>SD</given-names>
            </name>
            <name>
              <surname>Morley</surname>
              <given-names>JE</given-names>
            </name>
            <name>
              <surname>von Haehling</surname>
              <given-names>S</given-names>
            </name>
          </person-group>
          <article-title>Welcome to the ICD-10 code for sarcopenia</article-title>
          <source>J Cachexia Sarcopenia Muscle</source>
          <year>2016</year>
          <volume>7</volume>
          <issue>5</issue>
          <fpage>512</fpage>
          <lpage>514</lpage>
        </element-citation>
      </ref>
      <ref id="B5">
        <label>5</label>
        <mixed-citation>5 Fonseca G, Santos MRD, Souza FR, Costa M, Haehling SV, Takayama L, et al. Sympatho-vagal imbalance is associated with sarcopenia in male patients with heart failure. Arq Bras Cardiol. 2019; 112(6):739-746.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Fonseca</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Santos</surname>
              <given-names>MRD</given-names>
            </name>
            <name>
              <surname>Souza</surname>
              <given-names>FR</given-names>
            </name>
            <name>
              <surname>Costa</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Haehling</surname>
              <given-names>SV</given-names>
            </name>
            <name>
              <surname>Takayama</surname>
              <given-names>L</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Sympatho-vagal imbalance is associated with sarcopenia in male patients with heart failure</article-title>
          <source>Arq Bras Cardiol</source>
          <year>2019</year>
          <volume>112</volume>
          <issue>6</issue>
          <fpage>739</fpage>
          <lpage>746</lpage>
        </element-citation>
      </ref>
      <ref id="B6">
        <label>6</label>
        <mixed-citation>6 Araujo CGS, Castro CLB, Nobrega ACL. Heart rate responses to deep breathing and 4-seconds of exercise before and after pharmacological blockade with atropine and propranolol. Clin Auton Res. 1992;2(1):35-40.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Araujo</surname>
              <given-names>CGS</given-names>
            </name>
            <name>
              <surname>Castro</surname>
              <given-names>CLB</given-names>
            </name>
            <name>
              <surname>Nobrega</surname>
              <given-names>ACL</given-names>
            </name>
          </person-group>
          <article-title>Heart rate responses to deep breathing and 4-seconds of exercise before and after pharmacological blockade with atropine and propranolol</article-title>
          <source>Clin Auton Res</source>
          <year>1992</year>
          <volume>2</volume>
          <issue>1</issue>
          <fpage>35</fpage>
          <lpage>40</lpage>
        </element-citation>
      </ref>
      <ref id="B7">
        <label>7</label>
        <mixed-citation>7 Ara&#250;jo CG, Castro CL, Franca JF, Ramos PS. 4-Second exercise test reference values for ages 18-81 years. Arq Bras Cardiol. 2015;104(5):366-74.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Ara&#250;jo</surname>
              <given-names>CG</given-names>
            </name>
            <name>
              <surname>Castro</surname>
              <given-names>CL</given-names>
            </name>
            <name>
              <surname>Franca</surname>
              <given-names>JF</given-names>
            </name>
            <name>
              <surname>Ramos</surname>
              <given-names>PS</given-names>
            </name>
          </person-group>
          <article-title>4-Second exercise test reference values for ages 18-81 years</article-title>
          <source>Arq Bras Cardiol</source>
          <year>2015</year>
          <volume>104</volume>
          <issue>5</issue>
          <fpage>366</fpage>
          <lpage>374</lpage>
        </element-citation>
      </ref>
      <ref id="B8">
        <label>8</label>
        <mixed-citation>8 Araujo CG, Castro CL, Franca JF, Laukkanen JA, Hamar D, Myers J. Muscle power in upright row movement: predictor of all-cause mortality in individuals between 41 and 85 years of age: preliminary results. Eur J Prev Cardiol. 2019;26(6 (suppl)).</mixed-citation>
        <element-citation publication-type="book">
          <person-group person-group-type="author">
            <name>
              <surname>Araujo</surname>
              <given-names>CG</given-names>
            </name>
            <name>
              <surname>Castro</surname>
              <given-names>CL</given-names>
            </name>
            <name>
              <surname>Franca</surname>
              <given-names>JF</given-names>
            </name>
            <name>
              <surname>Laukkanen</surname>
              <given-names>JA</given-names>
            </name>
            <name>
              <surname>Hamar</surname>
              <given-names>D</given-names>
            </name>
            <name>
              <surname>Myers</surname>
              <given-names>J</given-names>
            </name>
          </person-group>
          <chapter-title>Muscle power in upright row movement: predictor of all-cause mortality in individuals between 41 and 85 years of age: preliminary results</chapter-title>
          <source>Eur J Prev Cardiol</source>
          <year>2019</year>
          <volume>26</volume>
          <issue>6</issue>
          <supplement>suppl</supplement>
        </element-citation>
      </ref>
      <ref id="B9">
        <label>9</label>
        <mixed-citation>9 Brito LBB, Ricardo DR, Ara&#250;jo DSMS, Ramos PS, Myers J, Ara&#250;jo CGS. Ability to sit and rise from the floor as a predictor of all-cause mortality. Eur J Prev Cardiol. 2014;21(7):892-8.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Brito</surname>
              <given-names>LBB</given-names>
            </name>
            <name>
              <surname>Ricardo</surname>
              <given-names>DR</given-names>
            </name>
            <name>
              <surname>Ara&#250;jo</surname>
              <given-names>DSMS</given-names>
            </name>
            <name>
              <surname>Ramos</surname>
              <given-names>PS</given-names>
            </name>
            <name>
              <surname>Myers</surname>
              <given-names>J</given-names>
            </name>
            <name>
              <surname>Ara&#250;jo</surname>
              <given-names>CGS</given-names>
            </name>
          </person-group>
          <article-title>Ability to sit and rise from the floor as a predictor of all-cause mortality</article-title>
          <source>Eur J Prev Cardiol</source>
          <year>2014</year>
          <volume>21</volume>
          <issue>7</issue>
          <fpage>892</fpage>
          <lpage>898</lpage>
        </element-citation>
      </ref>
      <ref id="B10">
        <label>10</label>
        <mixed-citation>10 Mitchell WK, Williams J, Atherton P, Larvin M, Lund J, Narici M. Sarcopenia, dynapenia, and the impact of advancing age on human skeletal muscle size and strength; a quantitative review. Front Physiol. 2012;3:260.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Mitchell</surname>
              <given-names>WK</given-names>
            </name>
            <name>
              <surname>Williams</surname>
              <given-names>J</given-names>
            </name>
            <name>
              <surname>Atherton</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>Larvin</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Lund</surname>
              <given-names>J</given-names>
            </name>
            <name>
              <surname>Narici</surname>
              <given-names>M</given-names>
            </name>
          </person-group>
          <article-title>Sarcopenia, dynapenia, and the impact of advancing age on human skeletal muscle size and strength; a quantitative review</article-title>
          <source>Front Physiol</source>
          <year>2012</year>
          <volume>3</volume>
          <fpage>260</fpage>
          <lpage>260</lpage>
        </element-citation>
      </ref>
      <ref id="B11">
        <label>11</label>
        <mixed-citation>11 Clark BC, Manini TM. Sarcopenia =/= dynapenia. J Gerontol A Biol Sci Med Sci. 2008;63(8):829-34.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Clark</surname>
              <given-names>BC</given-names>
            </name>
            <name>
              <surname>Manini</surname>
              <given-names>TM</given-names>
            </name>
          </person-group>
          <article-title>Sarcopenia =/= dynapenia</article-title>
          <source>J Gerontol A Biol Sci Med Sci</source>
          <year>2008</year>
          <volume>63</volume>
          <issue>8</issue>
          <fpage>829</fpage>
          <lpage>834</lpage>
        </element-citation>
      </ref>
      <ref id="B12">
        <label>12</label>
        <mixed-citation>12 De Ferrari GM, Dusi V, Ruffinazzi M, Gionti V, Cacciavillani L, Noussan P, et al. Physical inactivity is a risk factor for primary ventricular fibrillation. J Am Coll Cardiol. 2019;73(16):2117-8.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>De Ferrari</surname>
              <given-names>GM</given-names>
            </name>
            <name>
              <surname>Dusi</surname>
              <given-names>V</given-names>
            </name>
            <name>
              <surname>Ruffinazzi</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Gionti</surname>
              <given-names>V</given-names>
            </name>
            <name>
              <surname>Cacciavillani</surname>
              <given-names>L</given-names>
            </name>
            <name>
              <surname>Noussan</surname>
              <given-names>P</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Physical inactivity is a risk factor for primary ventricular fibrillation</article-title>
          <source>J Am Coll Cardiol</source>
          <year>2019</year>
          <volume>73</volume>
          <issue>16</issue>
          <fpage>2117</fpage>
          <lpage>2118</lpage>
        </element-citation>
      </ref>
      <ref id="B13">
        <label>13</label>
        <mixed-citation>13 Aagaard P, Suetta C, Caserotti P, Magnusson SP, Kjaer M. Role of the nervous system in sarcopenia and muscle atrophy with aging: strength training as a countermeasure. Scand J Med Sci Sports. 2010;20(1):49-64.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Aagaard</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>Suetta</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Caserotti</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>Magnusson</surname>
              <given-names>SP</given-names>
            </name>
            <name>
              <surname>Kjaer</surname>
              <given-names>M</given-names>
            </name>
          </person-group>
          <article-title>Role of the nervous system in sarcopenia and muscle atrophy with aging: strength training as a countermeasure</article-title>
          <source>Scand J Med Sci Sports</source>
          <year>2010</year>
          <volume>20</volume>
          <issue>1</issue>
          <fpage>49</fpage>
          <lpage>64</lpage>
        </element-citation>
      </ref>
    </ref-list>
  </back>
  <sub-article article-type="translation" id="s1" xml:lang="pt">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Minieditorial</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>M&#250;sculo Card&#237;aco e M&#250;sculo Esquel&#233;tico Conectados pelo Sistema Nervoso Aut&#244;nomo</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0001-6679-6695</contrib-id>
          <name>
            <surname>Araujo</surname>
            <given-names>Claudio Gil</given-names>
          </name>
          <xref ref-type="aff" rid="aff3">1</xref>
          <xref ref-type="corresp" rid="c2"/>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0002-3738-1586</contrib-id>
          <name>
            <surname>Laukkanen</surname>
            <given-names>Jari Antero</given-names>
          </name>
          <xref ref-type="aff" rid="aff4">2</xref>
        </contrib>
      </contrib-group>
      <aff id="aff3">
        <label>1</label>
        <institution content-type="original">Exercise Medicine Clinic - CLINIMEX, Rio de Janeiro, RJ - Brasil</institution>
      </aff>
      <aff id="aff4">
        <label>2</label>
        <institution content-type="original">University of Jyvaskyla - Faculty of Sport and Health Sciences, Jyvaskyla - Finl&#226;ndia</institution>
      </aff>
      <author-notes>
        <corresp id="c2"><bold>Correspond&#234;ncia: Claudio Gil Araujo,</bold> Rua Siqueira Campos, 93/101-103, CEP 22031-072, Rio de Janeiro, RJ - Brasil. E-mail: <email>cgaraujo@iis.com.br</email>
				</corresp>
      </author-notes>
      <kwd-group xml:lang="pt">
        <title>Palavras-chave</title>
        <kwd>Insufici&#234;ncia Card&#237;aca</kwd>
        <kwd>Mioc&#225;rdio</kwd>
        <kwd>M&#250;sculo Esquel&#233;tico</kwd>
        <kwd>Sistema Nervoso Aut&#244;nomo</kwd>
        <kwd>Homeostase</kwd>
        <kwd>Sarcopenia</kwd>
        <kwd>Sistema Nervoso Simp&#225;tico</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>O sistema nervoso aut&#244;nomo (SNA) exerce um papel fundamental na manuten&#231;&#227;o da homeostase celular e da vida humana. O funcionamento do cora&#231;&#227;o e dos m&#250;sculos esquel&#233;ticos &#233; em parte modulado pelos ramos simp&#225;ticos e parassimp&#225;ticos do SNA tanto em repouso como no exerc&#237;cio.</p>
      <p>Dados substanciais da literatura atestam o fato de que indicadores objetivos da for&#231;a muscular refletem o estado de sa&#250;de. J&#225; est&#225; bem estabelecido de que a insufici&#234;ncia card&#237;aca &#233; tipicamente acompanhada por anormalidades do m&#250;sculo esquel&#233;tico que contribuem &#224; intoler&#226;ncia ao exerc&#237;cio e baixa qualidade de vida relacionada &#224; sa&#250;de observadas nesses pacientes.<xref ref-type="bibr" rid="B1">1</xref><sup>,</sup><xref ref-type="bibr" rid="B2">2</xref> De fato, enquanto uma redu&#231;&#227;o na massa e na for&#231;a musculares &#233; naturalmente observada no processo de envelhecimento, principalmente ap&#243;s a quinta d&#233;cada de vida, isso torna-se ainda mais relevante em pacientes de meia idade e idosos com insufici&#234;ncia card&#237;aca.</p>
      <p>H&#225; muitas d&#233;cadas, o termo &#8220;sarcopenia&#8221; foi proposto como uma express&#227;o m&#233;dica para descrever a perda universal e involunt&#225;ria de massa muscular que ocorre com o aumento da idade.<xref ref-type="bibr" rid="B3">3</xref> No entanto, apesar de v&#225;rios crit&#233;rios terem sido propostos para caracteriz&#225;-la, do conhecimento crescente para compreender sua fisiopatologia e confirmar sua relev&#226;ncia cl&#237;nica e epidemiol&#243;gica, e de seu registro no CID-10,<xref ref-type="bibr" rid="B4">4</xref> ainda hoje, a sarcopenia &#233; raramente avaliada na pr&#225;tica cl&#237;nica di&#225;ria.</p>
      <p>Em um estudo colaborativo entre Brasil e Alemanha, Fonseca et al.,<xref ref-type="bibr" rid="B5">5</xref> analisaram dados de 116 pacientes do sexo masculino com insufici&#234;ncia card&#237;aca e fra&#231;&#227;o de eje&#231;&#227;o reduzida, submetidos ao teste de exerc&#237;cio cardiopulmonar m&#225;ximo em cicloerg&#244;metro, usando um protocolo de rampa. Ainda, utilizando-se a t&#233;cnica de microneurografia, a atividade nervosa simp&#225;tica muscular foi diretamente registrada do nervo peroneal e a atividade parassimp&#225;tica estimada pela magnitude da redu&#231;&#227;o da frequ&#234;ncia card&#237;aca nos primeiros dois minutos ap&#243;s o teste de exerc&#237;cio. Foram utilizadas absorciometria de raios-x de dupla energia (DEXA) e for&#231;a de preens&#227;o manual para as medidas de composi&#231;&#227;o corporal e for&#231;a muscular. Com base nessas medidas e nos crit&#233;rios padr&#245;es da literatura, os autores identificaram presen&#231;a ou n&#227;o de sarcopenia no grupo de pacientes. Reconhecemos a originalidade do estudo feito pelos autores, o qual pode dar uma contribui&#231;&#227;o significativa ao conhecimento existente na &#225;rea de pesquisa.</p>
      <p>Combinando todos esses dados, os autores buscaram uma rela&#231;&#227;o entre anormalidades no m&#250;sculo esquel&#233;tico card&#237;aco e disfun&#231;&#227;o do SNA, e tentaram quantificar a associa&#231;&#227;o entre as anormalidades do SNA e sarcopenia em pacientes do sexo masculino com insufici&#234;ncia card&#237;aca clinicamente est&#225;vel. Foi identificada sarcopenia em 33 (28%) dos pacientes com insufici&#234;ncia card&#237;aca e fra&#231;&#227;o de eje&#231;&#227;o reduzida, e esses pacientes apresentaram resultados das vari&#225;veis do SNA avaliadas significativamente distintos em compara&#231;&#227;o ao grupo de pacientes sem sarcopenia.<xref ref-type="bibr" rid="B5">5</xref> Ainda, os autores encontraram uma correla&#231;&#227;o significativa, ainda que modesta (r=-0,29) entre a massa muscular apendicular e a atividade nervosa simp&#225;tica muscular. Ao analisar os resultados com mais detalhes, &#233; poss&#237;vel verificar que existe uma sobreposi&#231;&#227;o consider&#225;vel entre os resultados dos pacientes com insufici&#234;ncia card&#237;aca e fra&#231;&#227;o de eje&#231;&#227;o reduzida com e sem sarcopenia, o que pode diminuir o valor cl&#237;nico dos achados.</p>
      <p>Baseados no protocolo do estudo de Fonseca et al.,<xref ref-type="bibr" rid="B5">5</xref> n&#243;s podemos especular que, caso os autores tivessem usado outros m&#233;todos de avalia&#231;&#227;o, tais como o teste de exerc&#237;cio de 4 segundos,<xref ref-type="bibr" rid="B6">6</xref><sup>,</sup><xref ref-type="bibr" rid="B7">7</xref> - um exame muito espec&#237;fico para avaliar a atividade vagal card&#237;aca - a for&#231;a de preens&#227;o manual em rela&#231;&#227;o ao peso corporal ou &#224; pot&#234;ncia muscular m&#225;xima,<xref ref-type="bibr" rid="B8">8</xref> ou mesmo um simples teste funcional como o teste de sentar e levantar,<xref ref-type="bibr" rid="B9">9</xref> poderiam ter encontrado outros valores discriminat&#243;rios, uma vez que todos esses testes s&#227;o mais espec&#237;ficos para avaliar dinapenia, condi&#231;&#227;o clinicamente mais relevante que a sarcopenia.<xref ref-type="bibr" rid="B10">10</xref><sup>,</sup><xref ref-type="bibr" rid="B11">11</xref>
			</p>
      <p>Por fim, &#233; poss&#237;vel que a pr&#225;tica de exerc&#237;cios f&#237;sicos regulares seja a maneira mais adequada para melhorar a sa&#250;de dos pacientes com insufici&#234;ncia card&#237;aca e fra&#231;&#227;o de eje&#231;&#227;o reduzida. Assim, esse estudo mostrou uma associa&#231;&#227;o entre disfun&#231;&#227;o do SNA card&#237;aco e anormalidades dos m&#250;sculos card&#237;aco e esquel&#233;tico. Isso, somado ao fato de que exerc&#237;cios aer&#243;bicos e resistidos regulares melhoram a modula&#231;&#227;o do SNA card&#237;aco, incluindo a diminui&#231;&#227;o do risco de fibrila&#231;&#227;o ventricular na ocorr&#234;ncia de um infarto do mioc&#225;rdio,<xref ref-type="bibr" rid="B12">12</xref> e que s&#227;o fortemente recomendados como parte do tratamento m&#233;dico de pacientes com sarcopenia e para aqueles com insufici&#234;ncia card&#237;aca e fra&#231;&#227;o de eje&#231;&#227;o reduzida;<xref ref-type="bibr" rid="B13">13</xref> &#233; bastante motivador pensar sobre o pr&#243;ximo passo esperado em pesquisa: um ensaio controlado randomizado com treinamento com exerc&#237;cios f&#237;sicos como interven&#231;&#227;o. Tal estudo avaliaria se a disfun&#231;&#227;o no SNA relatada por Fonseca et al.,<xref ref-type="bibr" rid="B5">5</xref> &#233; pass&#237;vel de revers&#227;o e, se sim, de que maneira isso melhoraria a qualidade de vida e outros desfechos em sa&#250;de dos pacientes com insufici&#234;ncia card&#237;aca e fra&#231;&#227;o de eje&#231;&#227;o reduzida.</p>
    </body>
    <back>
      <fn-group>
        <fn fn-type="other">
          <p>Minieditorial referente ao artigo: Desequil&#237;brio Simp&#225;tico-Vagal est&#225; Associado com Sarcopenia em Pacientes do Sexo Masculino com Insufici&#234;ncia Card&#237;aca</p>
        </fn>
      </fn-group>
    </back>
  </sub-article>
</article>
