<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0138-6557</journal-id>
<journal-title><![CDATA[Revista Cubana de Medicina Militar]]></journal-title>
<abbrev-journal-title><![CDATA[Rev Cub Med Mil]]></abbrev-journal-title>
<issn>0138-6557</issn>
<publisher>
<publisher-name><![CDATA[Centro Nacional de Información de Ciencias MédicasEditorial Ciencias Médicas]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0138-65572021000300016</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Evaluación de la frecuencia cardiaca durante la bipedestación activa inicial en pacientes que padecen síncope vasovagal]]></article-title>
<article-title xml:lang="en"><![CDATA[Evaluation of the heart rate during initial active standing in patients with vasovagal syncope]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Iglesias Alfonso]]></surname>
<given-names><![CDATA[José del Carmen]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Socarrás Hernández]]></surname>
<given-names><![CDATA[Bárbaro Nicolás]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Hospital Militar Central &#8220;Dr. Carlos J. Finlay&#8221;  ]]></institution>
<addr-line><![CDATA[ La Habana]]></addr-line>
<country>Cuba</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Centro de Investigación, Desarrollo y Producción &#8220;Grito de Baire&#8221;  ]]></institution>
<addr-line><![CDATA[ La Habana]]></addr-line>
<country>Cuba</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>09</month>
<year>2021</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>09</month>
<year>2021</year>
</pub-date>
<volume>50</volume>
<numero>3</numero>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_arttext&amp;pid=S0138-65572021000300016&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_abstract&amp;pid=S0138-65572021000300016&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_pdf&amp;pid=S0138-65572021000300016&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[RESUMEN  Introducción:  El síncope vasovagal es la causa más frecuente de pérdida breve de la conciencia, en su etiopatogenia se reporta una disfunción autonómica que puede ponerse de manifiesto en la bipedestación activa inmediata.  Objetivo: Comparar la dinámica de los cambios de la frecuencia cardíaca durante la bipedestación activa inmediata, de pacientes que padecen síncope vasovagal y sujetos controles.  Métodos: Se evaluaron 132 sujetos supuestamente sanos (grupo A) entre 18 y 25 años y 156 pacientes con síncopes vasovagales; fueron divididos por su respuesta ante la bipedestación prolongada, negativa 111 (grupo B) y positiva 45 (grupo C). Se registró la actividad electrocardiográfica en decúbito supino y al inicio de la bipedestación activa, se obtuvo las secuencias de intervalos RR. Se comparó la frecuencia cardíaca en los 3 grupos, con 22 indicadores (posicionales, temporales, ordinales y relacionales, promedio y de la velocidad de los cambios).  Resultados: No hubo diferencias en los indicadores promedio, sin embargo, algunos que evalúan la velocidad del cambio inicial, fueron significativamente menores en el grupo A comparado con B y C (p &lt; 0,05), mientras que los que evalúan la velocidad de recuperación, fueron significativamente menores en el grupo C comparado con A y B.  Conclusión: La dinámica de los cambios de frecuencia, permitió encontrar indicadores que pueden considerarse posibles predictores de una respuesta cardiovascular inadecuada en pacientes con síncope vasovagal.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[ABSTRACT  Introduction:  Vasovagal syncope is the most frequent cause of brief loss of consciousness, in its etiopathogenesis an autonomic dysfunction is reported that can be manifested in immediate active standing.  Objective:  To compare the dynamics of heart rate changes during immediate active standing of patients suffering from vasovagal syncope with control subjects.  Methods:  132 supposedly healthy subjects (group A) between 18 and 25 years old and 156 patients with vasovagal syncope were evaluated, which were divided by their response to prolonged standing, negative 111 (group B) and positive 45 (group C). Electrocardiographic activity was recorded in the supine position and at the beginning of active standing, the sequences of RR intervals were obtained. The heart rate was compared in the 3 groups, using 22 indicators (positional, temporal, ordinal and relational, average and of the speed of changes).  Results:  Differences were not found in the average indicators in the analyzed period, however, some that evaluate the speed of the initial change were significantly lower in group A compared to B and C (p &lt; 0.05), while others that evaluate the speed recovery rates were significantly lower in group C compared to A and B. This allows to characterize, compare and differentiate the groups studied during the complex and rapid interactions that occur in the change of position.  Conclusion:  The dynamic of frequency changes, allowed to find indicators, which can be considered as possible predictors of an inadequate cardiovascular response in patients with vasovagal syncope.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[síncope vasovagal]]></kwd>
<kwd lng="es"><![CDATA[frecuencia cardiaca]]></kwd>
<kwd lng="es"><![CDATA[bipedestación activa]]></kwd>
<kwd lng="es"><![CDATA[sistema nervioso autónomo]]></kwd>
<kwd lng="en"><![CDATA[vasovagal syncope]]></kwd>
<kwd lng="en"><![CDATA[heart rate]]></kwd>
<kwd lng="en"><![CDATA[active standing]]></kwd>
<kwd lng="en"><![CDATA[autonomic nervous system]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<label>1</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Lara]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Mori]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Síncope]]></article-title>
<source><![CDATA[Medicina Infantil]]></source>
<year>2019</year>
<volume>XXVI</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>205-10</page-range></nlm-citation>
</ref>
<ref id="B2">
<label>2</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Brignole]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Moya]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[de Lange]]></surname>
<given-names><![CDATA[FJ]]></given-names>
</name>
<name>
<surname><![CDATA[Deharo]]></surname>
<given-names><![CDATA[JC]]></given-names>
</name>
<name>
<surname><![CDATA[Elliott]]></surname>
<given-names><![CDATA[PM]]></given-names>
</name>
<name>
<surname><![CDATA[Fanciulli]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[2018 ESC Guidelines for the diagnosis and management of syncope]]></article-title>
<source><![CDATA[European Heart Journal]]></source>
<year>2018</year>
<volume>39</volume>
<numero>21</numero>
<issue>21</issue>
<page-range>1883-48</page-range></nlm-citation>
</ref>
<ref id="B3">
<label>3</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ghariq]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Thijs]]></surname>
<given-names><![CDATA[RD]]></given-names>
</name>
<name>
<surname><![CDATA[Bek]]></surname>
<given-names><![CDATA[LM]]></given-names>
</name>
<name>
<surname><![CDATA[Van Zwet]]></surname>
<given-names><![CDATA[EW]]></given-names>
</name>
<name>
<surname><![CDATA[Benditt]]></surname>
<given-names><![CDATA[DG]]></given-names>
</name>
<name>
<surname><![CDATA[Van Dijk]]></surname>
<given-names><![CDATA[JG]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[A higher proportion of menthan of women fainted in the phase without nitroglycerin in tilt-induced vasovagal syncope]]></article-title>
<source><![CDATA[Clinical Autonomic Research]]></source>
<year>2020</year>
<volume>30</volume>
<page-range>441-7</page-range></nlm-citation>
</ref>
<ref id="B4">
<label>4</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hall]]></surname>
<given-names><![CDATA[JE]]></given-names>
</name>
</person-group>
<source><![CDATA[Guyton y Hall: tratado de fisiología médica]]></source>
<year>2016</year>
<edition>13</edition>
<publisher-loc><![CDATA[Barcelona ]]></publisher-loc>
<publisher-name><![CDATA[Elsevier Health Sciences Spain]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B5">
<label>5</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Wieling]]></surname>
<given-names><![CDATA[W]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Standing, orthostatic stress, and autonomic function]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Bannister]]></surname>
<given-names><![CDATA[R]]></given-names>
</name>
</person-group>
<source><![CDATA[Autonomic failure: a textbook of clinical disorders of the autonomic nervous system]]></source>
<year>1988</year>
<page-range>308-20</page-range><publisher-loc><![CDATA[Oxford ]]></publisher-loc>
<publisher-name><![CDATA[Oxford Medical Publications]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B6">
<label>6</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ewing]]></surname>
<given-names><![CDATA[DJ]]></given-names>
</name>
<name>
<surname><![CDATA[Martyn]]></surname>
<given-names><![CDATA[CN]]></given-names>
</name>
<name>
<surname><![CDATA[Young]]></surname>
<given-names><![CDATA[RJ]]></given-names>
</name>
<name>
<surname><![CDATA[Clarke]]></surname>
<given-names><![CDATA[BF]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The value of cardiovascular autonomic function tests: 10 years experience in diabetes]]></article-title>
<source><![CDATA[Diabetes Care]]></source>
<year>1985</year>
<volume>8</volume>
<numero>5</numero>
<issue>5</issue>
<page-range>491-8</page-range></nlm-citation>
</ref>
<ref id="B7">
<label>7</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Campbell]]></surname>
<given-names><![CDATA[IW]]></given-names>
</name>
<name>
<surname><![CDATA[Ewing]]></surname>
<given-names><![CDATA[DJ]]></given-names>
</name>
<name>
<surname><![CDATA[Clarke]]></surname>
<given-names><![CDATA[BF]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Tests of cardiovascular reflex function in diabetic autonomic neuropathy]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[FA]]></surname>
<given-names><![CDATA[Gries]]></given-names>
</name>
<name>
<surname><![CDATA[HJ]]></surname>
<given-names><![CDATA[Freund]]></given-names>
</name>
<name>
<surname><![CDATA[F]]></surname>
<given-names><![CDATA[Rube]]></given-names>
</name>
<name>
<surname><![CDATA[H]]></surname>
<given-names><![CDATA[Berger]]></given-names>
</name>
</person-group>
<source><![CDATA[Aspects of autonomic neuropathy in diabetics]]></source>
<year>1979</year>
<page-range>61-8</page-range><publisher-loc><![CDATA[Stuttgart ]]></publisher-loc>
<publisher-name><![CDATA[Georg Thieme Verlag]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B8">
<label>8</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Sundkvist]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
<name>
<surname><![CDATA[Lilja]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Almer]]></surname>
<given-names><![CDATA[LO]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Deep breathing, Valsalva, and tilt table tests in diabetics with and without symptoms of autonomic neuropathy]]></article-title>
<source><![CDATA[Acta Med Scand]]></source>
<year>1982</year>
<volume>211</volume>
<page-range>369-73</page-range></nlm-citation>
</ref>
<ref id="B9">
<label>9</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Borst]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
<name>
<surname><![CDATA[Wieling]]></surname>
<given-names><![CDATA[W]]></given-names>
</name>
<name>
<surname><![CDATA[Van Brederode]]></surname>
<given-names><![CDATA[JFM]]></given-names>
</name>
<name>
<surname><![CDATA[Hond]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[de Rijk]]></surname>
<given-names><![CDATA[LG]]></given-names>
</name>
<name>
<surname><![CDATA[Dunning]]></surname>
<given-names><![CDATA[AJ]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Mechanisms of initial heart rate response to postural change]]></article-title>
<source><![CDATA[Am J Physiol]]></source>
<year>1982</year>
<volume>243</volume>
<numero>6</numero>
<issue>6</issue>
<page-range>H676-H81</page-range></nlm-citation>
</ref>
<ref id="B10">
<label>10</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Wieling]]></surname>
<given-names><![CDATA[W]]></given-names>
</name>
<name>
<surname><![CDATA[Borst]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
<name>
<surname><![CDATA[Van Brederode]]></surname>
<given-names><![CDATA[JFM]]></given-names>
</name>
<name>
<surname><![CDATA[Van Dongen Torman]]></surname>
<given-names><![CDATA[MA]]></given-names>
</name>
<name>
<surname><![CDATA[Van Montfrans]]></surname>
<given-names><![CDATA[GA]]></given-names>
</name>
<name>
<surname><![CDATA[Dunning]]></surname>
<given-names><![CDATA[AJ]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Testing for autonomic neuropathy: heart rate changes after orthostatic maneuvers and static muscle contractions]]></article-title>
<source><![CDATA[Clin Sci]]></source>
<year>1983</year>
<volume>64</volume>
<page-range>581-6</page-range></nlm-citation>
</ref>
<ref id="B11">
<label>11</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Cybulski]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
<name>
<surname><![CDATA[Niewiadomski]]></surname>
<given-names><![CDATA[W]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Influence of age on the immediate heart rate response to the active orthostatic test]]></article-title>
<source><![CDATA[Physiol Pharmacol]]></source>
<year>2003</year>
<volume>54</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>65-80</page-range></nlm-citation>
</ref>
<ref id="B12">
<label>12</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Iglesias Alfonso]]></surname>
<given-names><![CDATA[JC]]></given-names>
</name>
<name>
<surname><![CDATA[Aldana Vilas]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
<name>
<surname><![CDATA[García Gutiérrez]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<name>
<surname><![CDATA[Vázquez Díaz Granados]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Frecuencia cardiaca en la bipedestación activa inmediata en jóvenes sanos]]></article-title>
<source><![CDATA[Revista cubana de medicina militar]]></source>
<year>2010</year>
<volume>39</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>104-15</page-range></nlm-citation>
</ref>
<ref id="B13">
<label>13</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Machado]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Estévez]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
</person-group>
<source><![CDATA[Software to digitize electrocardiograms and quantify heart rate variability in humans]]></source>
<year>2008</year>
<publisher-name><![CDATA[Manual ZZ, The Universal Manual Library]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B14">
<label>14</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Iglesias]]></surname>
<given-names><![CDATA[JC]]></given-names>
</name>
<name>
<surname><![CDATA[Reyes]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
<name>
<surname><![CDATA[Delgado]]></surname>
<given-names><![CDATA[O]]></given-names>
</name>
<name>
<surname><![CDATA[Sánchez]]></surname>
<given-names><![CDATA[K]]></given-names>
</name>
<name>
<surname><![CDATA[Quevedo]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
</person-group>
<source><![CDATA[Manual del Usuario del Sistema de Registro y Procesamiento del Ritmo Cardiaco]]></source>
<year>1997</year>
<publisher-loc><![CDATA[La Habana ]]></publisher-loc>
<publisher-name><![CDATA[Ritmocard]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B15">
<label>15</label><nlm-citation citation-type="">
<collab>StatSoft, Inc</collab>
<source><![CDATA[STATISTICS (data analysis software system)]]></source>
<year>2013</year>
</nlm-citation>
</ref>
<ref id="B16">
<label>16</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Grubb]]></surname>
<given-names><![CDATA[BP]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Neurocardiogenic syncope and related disorders of orthostatic intolerance]]></article-title>
<source><![CDATA[Circulation]]></source>
<year>2005</year>
<volume>111</volume>
<numero>22</numero>
<issue>22</issue>
<page-range>2997-3006</page-range></nlm-citation>
</ref>
<ref id="B17">
<label>17</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Purves]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Augustine]]></surname>
<given-names><![CDATA[GJ]]></given-names>
</name>
<name>
<surname><![CDATA[Fitzpatrick]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Hall]]></surname>
<given-names><![CDATA[WC]]></given-names>
</name>
<name>
<surname><![CDATA[Lamantia]]></surname>
<given-names><![CDATA[AS]]></given-names>
</name>
<name>
<surname><![CDATA[Mc Namara]]></surname>
<given-names><![CDATA[JO]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Visceral Motor System]]></article-title>
<source><![CDATA[Neuroscience]]></source>
<year>2004</year>
<edition>3rd</edition>
<page-range>469-99</page-range><publisher-loc><![CDATA[Sunderland, MA ]]></publisher-loc>
<publisher-name><![CDATA[Sinauer Associates, Inc]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B18">
<label>18</label><nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Estévez]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
</person-group>
<source><![CDATA[Visión clásica del Sistema Nervioso Autónomo. Habana, Instituto Nacional de Neurología y Neurocirugía]]></source>
<year>2007</year>
</nlm-citation>
</ref>
<ref id="B19">
<label>19</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Pagani]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Lombardi]]></surname>
<given-names><![CDATA[F]]></given-names>
</name>
<name>
<surname><![CDATA[Guzzetti]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Rimoldi]]></surname>
<given-names><![CDATA[O]]></given-names>
</name>
<name>
<surname><![CDATA[Furlan]]></surname>
<given-names><![CDATA[R]]></given-names>
</name>
<name>
<surname><![CDATA[Pizzinelli]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Power spectral analysis of heart rate and arterial pressure variabilities as a marker of sympathovagal interaction in man and conscious dog]]></article-title>
<source><![CDATA[Circ Res]]></source>
<year>1986</year>
<volume>59</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>178-93</page-range></nlm-citation>
</ref>
<ref id="B20">
<label>20</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mallat]]></surname>
<given-names><![CDATA[Z]]></given-names>
</name>
<name>
<surname><![CDATA[Vicaut]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<name>
<surname><![CDATA[Sangare&#769;]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Verschueren]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Fontaine]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
<name>
<surname><![CDATA[Frank]]></surname>
<given-names><![CDATA[R]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Prediction of head-up tilt test result by analysis of early heart rate variations]]></article-title>
<source><![CDATA[Circulation]]></source>
<year>1997</year>
<volume>96</volume>
<page-range>581-4</page-range></nlm-citation>
</ref>
<ref id="B21">
<label>21</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[García]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Lacunza]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Rojo]]></surname>
<given-names><![CDATA[JL]]></given-names>
</name>
<name>
<surname><![CDATA[Sánchez]]></surname>
<given-names><![CDATA[JJ]]></given-names>
</name>
<name>
<surname><![CDATA[Juan Martínez]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Jesús Requena]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[El incremento temprano de la frecuencia cardiaca no predice el resultado de la prueba de mesa basculante potenciada con nitroglicerina]]></article-title>
<source><![CDATA[Rev Esp Cardiol]]></source>
<year>2005</year>
<volume>58</volume>
<page-range>499-503</page-range></nlm-citation>
</ref>
<ref id="B22">
<label>22</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kovalchuk]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
<name>
<surname><![CDATA[Boyarchuk]]></surname>
<given-names><![CDATA[O]]></given-names>
</name>
<name>
<surname><![CDATA[Pavlyshyn]]></surname>
<given-names><![CDATA[H]]></given-names>
</name>
<name>
<surname><![CDATA[Balatska]]></surname>
<given-names><![CDATA[N]]></given-names>
</name>
<name>
<surname><![CDATA[Luchyshyn]]></surname>
<given-names><![CDATA[N]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Analysis of heart rate variability in paediatric patients with vasovagal syncope]]></article-title>
<source><![CDATA[Pediatr Pol]]></source>
<year>2019</year>
<volume>94</volume>
<numero>6</numero>
<issue>6</issue>
<page-range>357-67</page-range></nlm-citation>
</ref>
<ref id="B23">
<label>23</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Eéstvz]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Carricarte]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
<name>
<surname><![CDATA[Denis Jas J Rodríguez]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<name>
<surname><![CDATA[Machado]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
<name>
<surname><![CDATA[Montes]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Influence of Heart Rate, Age, and Gender on Heart Rate Variability in Adolescents and Young Adults]]></article-title>
<source><![CDATA[Adv Exp Med Biol-Clinical and Experimental Biomedicine]]></source>
<year>2019</year>
<volume>4</volume>
<page-range>19-33</page-range></nlm-citation>
</ref>
</ref-list>
</back>
</article>
