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Time course of changes in heart rate and blood pressure variability in rats with myocardial infarction

Our aim was to determine the time course of changes in autonomic balance in the acute (1 and 3 days), sub-acute (7 days) and chronic (28 days) phases of myocardial infarction (MI) in rats. Autonomic balance was assessed by temporal and spectral analyses of blood pressure variability (BPV) and heart...

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Autores principales: Aires, R., Pimentel, E.B., Forechi, L., Dantas, E.M., Mill, J.G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Associação Brasileira de Divulgação Científica 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5264537/
https://www.ncbi.nlm.nih.gov/pubmed/28076450
http://dx.doi.org/10.1590/1414-431X20165511
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author Aires, R.
Pimentel, E.B.
Forechi, L.
Dantas, E.M.
Mill, J.G.
author_facet Aires, R.
Pimentel, E.B.
Forechi, L.
Dantas, E.M.
Mill, J.G.
author_sort Aires, R.
collection PubMed
description Our aim was to determine the time course of changes in autonomic balance in the acute (1 and 3 days), sub-acute (7 days) and chronic (28 days) phases of myocardial infarction (MI) in rats. Autonomic balance was assessed by temporal and spectral analyses of blood pressure variability (BPV) and heart rate variability (HRV). Pulsatile blood pressure (BP) recordings (30 min) were obtained in awake and unrestrained male Wistar rats (N = 77; 8-10 weeks old) with MI (coronary ligature) or sham operation (SO). Data are reported as means±SE. The high frequency (HF) component (n.u.) of HRV was significantly lower in MI-1- (P<0.01) and MI-3-day rats (P<0.05) than in their time-control groups (SO-1=68±4 vs MI-1=35.3±4.3; SO-3=71±5.8 vs MI-3=45.2±3.8), without differences thereafter (SO-7=69.2±4.8 vs MI-7=56±5.8; SO-28=73±4 vs MI-28=66±6.6). A sharp reduction (P<0.05) of BPV (mmHg(2)) was observed in the first week after MI (SO-1=8.55±0.80; SO-3=9.11±1.08; SO-7=7.92±1.10 vs MI-1=5.63±0.73; MI-3=5.93±0.30; MI-7=5.30±0.25). Normal BPV, however, was observed 4 weeks after MI (SO-28=8.60±0.66 vs MI-28=8.43±0.56 mmHg(2); P>0.05). This reduction was mainly due to attenuation of the low frequency (LF) band of BPV in absolute and normalized units (SO-1=39.3±7%; SO-3=55±4.5%; SO-7=46.8±4.5%; SO-28=45.7±5%; MI-1=13±3.5%; MI-3=35±4.7%; MI-7=25±2.8%; MI-28=21.4±2.8%). The results suggest that the reduction in HRV was associated with decrease of the HF component of HRV suggesting recovery of the vagal control of heartbeats along the post-infarction healing period. The depression of BPV was more dependent on the attenuation of the LF component, which is linked to the baroreflex modulation of the autonomic balance.
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spelling pubmed-52645372017-02-14 Time course of changes in heart rate and blood pressure variability in rats with myocardial infarction Aires, R. Pimentel, E.B. Forechi, L. Dantas, E.M. Mill, J.G. Braz J Med Biol Res Biomedical Sciences Our aim was to determine the time course of changes in autonomic balance in the acute (1 and 3 days), sub-acute (7 days) and chronic (28 days) phases of myocardial infarction (MI) in rats. Autonomic balance was assessed by temporal and spectral analyses of blood pressure variability (BPV) and heart rate variability (HRV). Pulsatile blood pressure (BP) recordings (30 min) were obtained in awake and unrestrained male Wistar rats (N = 77; 8-10 weeks old) with MI (coronary ligature) or sham operation (SO). Data are reported as means±SE. The high frequency (HF) component (n.u.) of HRV was significantly lower in MI-1- (P<0.01) and MI-3-day rats (P<0.05) than in their time-control groups (SO-1=68±4 vs MI-1=35.3±4.3; SO-3=71±5.8 vs MI-3=45.2±3.8), without differences thereafter (SO-7=69.2±4.8 vs MI-7=56±5.8; SO-28=73±4 vs MI-28=66±6.6). A sharp reduction (P<0.05) of BPV (mmHg(2)) was observed in the first week after MI (SO-1=8.55±0.80; SO-3=9.11±1.08; SO-7=7.92±1.10 vs MI-1=5.63±0.73; MI-3=5.93±0.30; MI-7=5.30±0.25). Normal BPV, however, was observed 4 weeks after MI (SO-28=8.60±0.66 vs MI-28=8.43±0.56 mmHg(2); P>0.05). This reduction was mainly due to attenuation of the low frequency (LF) band of BPV in absolute and normalized units (SO-1=39.3±7%; SO-3=55±4.5%; SO-7=46.8±4.5%; SO-28=45.7±5%; MI-1=13±3.5%; MI-3=35±4.7%; MI-7=25±2.8%; MI-28=21.4±2.8%). The results suggest that the reduction in HRV was associated with decrease of the HF component of HRV suggesting recovery of the vagal control of heartbeats along the post-infarction healing period. The depression of BPV was more dependent on the attenuation of the LF component, which is linked to the baroreflex modulation of the autonomic balance. Associação Brasileira de Divulgação Científica 2017-01-09 /pmc/articles/PMC5264537/ /pubmed/28076450 http://dx.doi.org/10.1590/1414-431X20165511 Text en http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Biomedical Sciences
Aires, R.
Pimentel, E.B.
Forechi, L.
Dantas, E.M.
Mill, J.G.
Time course of changes in heart rate and blood pressure variability in rats with myocardial infarction
title Time course of changes in heart rate and blood pressure variability in rats with myocardial infarction
title_full Time course of changes in heart rate and blood pressure variability in rats with myocardial infarction
title_fullStr Time course of changes in heart rate and blood pressure variability in rats with myocardial infarction
title_full_unstemmed Time course of changes in heart rate and blood pressure variability in rats with myocardial infarction
title_short Time course of changes in heart rate and blood pressure variability in rats with myocardial infarction
title_sort time course of changes in heart rate and blood pressure variability in rats with myocardial infarction
topic Biomedical Sciences
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5264537/
https://www.ncbi.nlm.nih.gov/pubmed/28076450
http://dx.doi.org/10.1590/1414-431X20165511
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