Mechanical deconditioning of the heart due to long-term bed rest as observed on seismocardiogram morphology
Abstract During head-down tilt bed rest (HDT) the cardiovascular system is subject to headward fluid shifts. The fluid shift phenomenon is analogous to weightlessness experienced during spaceflight microgravity. The purpose of this study was to investigate the effect of prolonged 60-day bed rest on...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2022-07-01
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| Series: | npj Microgravity |
| Online Access: | https://doi.org/10.1038/s41526-022-00206-7 |
| _version_ | 1797642304706576384 |
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| author | Bradley Hoffmann Parastoo Dehkordi Farzad Khosrow-Khavar Nandu Goswami Andrew P. Blaber Kouhyar Tavakolian |
| author_facet | Bradley Hoffmann Parastoo Dehkordi Farzad Khosrow-Khavar Nandu Goswami Andrew P. Blaber Kouhyar Tavakolian |
| author_sort | Bradley Hoffmann |
| collection | DOAJ |
| description | Abstract During head-down tilt bed rest (HDT) the cardiovascular system is subject to headward fluid shifts. The fluid shift phenomenon is analogous to weightlessness experienced during spaceflight microgravity. The purpose of this study was to investigate the effect of prolonged 60-day bed rest on the mechanical performance of the heart using the morphology of seismocardiography (SCG). Three-lead electrocardiogram (ECG), SCG and blood pressure recordings were collected simultaneously from 20 males in a 60-day HDT study (MEDES, Toulouse, France). The study was divided into two campaigns of ten participants. The first commenced in January, and the second in September. Signals were recorded in the supine position during the baseline data collection (BDC) before bed rest, during 6° HDT bed rest and during recovery (R), post-bed rest. Using SCG and blood pressure at the finger, the following were determined: Pulse Transit Time (PTT); and left-ventricular ejection time (LVET). SCG morphology was analyzed using functional data analysis (FDA). The coefficients of the model were estimated over 20 cycles of SCG recordings of BDC12 and HDT52. SCG fiducial morphology AO (aortic valve opening) and AC (aortic valve closing) amplitudes showed significant decrease between BDC12 and HDT52 (p < 0.03). PTT and LVET were also found to decrease through HDT bed rest (p < 0.01). Furthermore, PTT and LVET magnitude of response to bed rest was found to be different between campaigns (p < 0.001) possibly due to seasonal effects on of the cardiovascular system. Correlations between FDA and cardiac timing intervals PTT and LVET using SCG suggests decreases in mechanical strength of the heart and increased arterial stiffness due to fluid shifts associated with the prolonged bed rest. |
| first_indexed | 2024-03-11T13:58:07Z |
| format | Article |
| id | doaj.art-6fee3b6122454f3ba51f0aa586af954b |
| institution | Directory Open Access Journal |
| issn | 2373-8065 |
| language | English |
| last_indexed | 2024-03-11T13:58:07Z |
| publishDate | 2022-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj Microgravity |
| spelling | doaj.art-6fee3b6122454f3ba51f0aa586af954b2023-11-02T05:36:13ZengNature Portfolionpj Microgravity2373-80652022-07-01811910.1038/s41526-022-00206-7Mechanical deconditioning of the heart due to long-term bed rest as observed on seismocardiogram morphologyBradley Hoffmann0Parastoo Dehkordi1Farzad Khosrow-Khavar2Nandu Goswami3Andrew P. Blaber4Kouhyar Tavakolian5University of North Dakota School of Electrical Engineering & Computer ScienceHeart Force Medical IncHeart Force Medical IncPhysiology Division, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of GrazUniversity of North Dakota School of Electrical Engineering & Computer ScienceUniversity of North Dakota School of Electrical Engineering & Computer ScienceAbstract During head-down tilt bed rest (HDT) the cardiovascular system is subject to headward fluid shifts. The fluid shift phenomenon is analogous to weightlessness experienced during spaceflight microgravity. The purpose of this study was to investigate the effect of prolonged 60-day bed rest on the mechanical performance of the heart using the morphology of seismocardiography (SCG). Three-lead electrocardiogram (ECG), SCG and blood pressure recordings were collected simultaneously from 20 males in a 60-day HDT study (MEDES, Toulouse, France). The study was divided into two campaigns of ten participants. The first commenced in January, and the second in September. Signals were recorded in the supine position during the baseline data collection (BDC) before bed rest, during 6° HDT bed rest and during recovery (R), post-bed rest. Using SCG and blood pressure at the finger, the following were determined: Pulse Transit Time (PTT); and left-ventricular ejection time (LVET). SCG morphology was analyzed using functional data analysis (FDA). The coefficients of the model were estimated over 20 cycles of SCG recordings of BDC12 and HDT52. SCG fiducial morphology AO (aortic valve opening) and AC (aortic valve closing) amplitudes showed significant decrease between BDC12 and HDT52 (p < 0.03). PTT and LVET were also found to decrease through HDT bed rest (p < 0.01). Furthermore, PTT and LVET magnitude of response to bed rest was found to be different between campaigns (p < 0.001) possibly due to seasonal effects on of the cardiovascular system. Correlations between FDA and cardiac timing intervals PTT and LVET using SCG suggests decreases in mechanical strength of the heart and increased arterial stiffness due to fluid shifts associated with the prolonged bed rest.https://doi.org/10.1038/s41526-022-00206-7 |
| spellingShingle | Bradley Hoffmann Parastoo Dehkordi Farzad Khosrow-Khavar Nandu Goswami Andrew P. Blaber Kouhyar Tavakolian Mechanical deconditioning of the heart due to long-term bed rest as observed on seismocardiogram morphology npj Microgravity |
| title | Mechanical deconditioning of the heart due to long-term bed rest as observed on seismocardiogram morphology |
| title_full | Mechanical deconditioning of the heart due to long-term bed rest as observed on seismocardiogram morphology |
| title_fullStr | Mechanical deconditioning of the heart due to long-term bed rest as observed on seismocardiogram morphology |
| title_full_unstemmed | Mechanical deconditioning of the heart due to long-term bed rest as observed on seismocardiogram morphology |
| title_short | Mechanical deconditioning of the heart due to long-term bed rest as observed on seismocardiogram morphology |
| title_sort | mechanical deconditioning of the heart due to long term bed rest as observed on seismocardiogram morphology |
| url | https://doi.org/10.1038/s41526-022-00206-7 |
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