scholarly journals Interrelationships between pulse arrival time and arterial blood pressure during postural transitions before and after spaceflight

2019 ◽  
Vol 127 (4) ◽  
pp. 1050-1057
Author(s):  
Katelyn N. Wood ◽  
Danielle K. Greaves ◽  
Richard L. Hughson
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Arrival Time ◽  
Standing Posture ◽  
Pulse Arrival Time ◽  
Arterial Blood ◽  
Increased Risk ◽  
Before And After ◽  
Acute Changes ◽  
Pulse Arrival

We tested the hypothesis that acute changes in arterial blood pressure (BP) when astronauts moved between supine and standing posture before and after spaceflight can be tracked by beat-to-beat changes in pulse arrival time (PAT). Nine male crewmembers (45 ± 7 yr of age; mean mission length: 165 ± 13 days) participated in a standardized supine-to-sit-to-stand test (5 min-30 s-3 min) before flight and 1 day following return to Earth with continuous monitoring of ECG and finger arterial BP. PAT was determined from the R-wave of the ECG to the foot of the BP waveform. On average, modest cardiovascular deconditioning was detected by ~10 beats/min increase in heart rate in supine and standing posture after spaceflight ( P < 0.05). When looking across the full data collection period, the r2 values between inverse of PAT (1/PAT) and systolic (SBP) and diastolic BP (DBP) varied considerably between individuals (SBP preflight 0.142 ± 0.186, postflight 0.262 ± 0.243). Individual variability was consistent during periods of transition (SBP preflight 0.284 ± 0.324, postflight 0.297 ± 0.269); however, when SBP dropped >20 mmHg, r2 was significant in 5 of 5 preflight tests and 5 of 7 postflight tests. The standard error of the estimate based on a simple linear model during both pre- and postflight testing was 9–11 mmHg for SBP and 6–7 mmHg for DBP. Overall, the results support the hypothesis that PAT tracked dynamic changes in BP. PAT as a noninvasive, nonintrusive surrogate for changes in BP could be developed as an indicator of risk for syncope on return from spaceflight or other Earth-based applications. NEW & NOTEWORTHY Astronauts returning to Earth’s gravity are at increased risk of low blood pressure on standing. Arterial pulse arrival time tracked the decrease in arterial blood pressure on moving from supine to upright posture. Nonintrusive technology providing indicators sensitive to acute changes in blood pressure could act as an early warning system to identify risk for hypotension that place astronauts, or people on Earth, at risk of impaired cognitive performance, fainting, and falls.

scholarly journals Real-Time Monitoring of Blood Pressure Using Digitalized Pulse Arrival Time Calculation Technology for Prompt Detection of Sudden Hypertensive Episodes During Laryngeal Microsurgery: Retrospective Observational Study (Preprint)

2018 ◽  
Author(s):  
Yong-Seok Park ◽  
Sung-Hoon Kim ◽  
Yoon Se Lee ◽  
Seung-Ho Choi ◽  
Seung-Woo Ku ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Arrival Time ◽  
Characteristic Curve ◽  
Sudden Change ◽  
Area Under The Curve ◽  
Sudden Increase ◽  
Maximum Slope ◽  
Pulse Arrival Time ◽  
Before And After ◽  
Pulse Arrival

BACKGROUND Laryngeal microsurgery (LMS) is often accompanied by a sudden increase in blood pressure (BP) during surgery because of stimulation around the larynx. This sudden change in the hemodynamic status is not immediately reflected in a casual cuff-type measurement that takes intermittent readings every 3 to 5 min. OBJECTIVE This study aimed to investigate the potential of pulse arrival time (PAT) as a marker for a BP surge, which usually occurs in patients undergoing LMS. METHODS Intermittent measurements of BP and electrocardiogram (ECG) and photoplethysmogram (PPG) signals were recorded during LMS. PAT was defined as the interval between the R-peak on the ECG and the maximum slope on the PPG. Mean PAT values before and after BP increase were compared. PPG-related parameters and the correlations between changes in these variables were calculated. RESULTS BP surged because of laryngoscopic manipulation (mean systolic BP [SBP] from 115.3, SD 21.4 mmHg, to 159.9, SD 25.2 mmHg; <i>P</i>&lt;.001), whereas PAT decreased significantly (from mean 460.6, SD 51.9 ms, to 405.8, SD 50.1 ms; <i>P</i>&lt;.001) in most of the cases. The change in SBP showed a significant correlation with the inverse of the PAT (<i>r</i>=0.582; <i>P</i>&lt;.001). Receiver-operating characteristic curve analysis indicated that an increase of 11.5% in the inverse of the PAT could detect a 40% increase in SBP, and the area under the curve was 0.814. CONCLUSIONS During LMS, where invasive arterial catheterization is not always possible, PAT shows good correlation with SBP and may, therefore, have the potential to identify abrupt BP surges during laryngoscopic manipulations in a noninvasive manner. CLINICALTRIAL

scholarly journals Real-Time Monitoring of Blood Pressure Using Digitalized Pulse Arrival Time Calculation Technology for Prompt Detection of Sudden Hypertensive Episodes During Laryngeal Microsurgery: Retrospective Observational Study

10.2196/13156 ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. e13156
Author(s):  
Yong-Seok Park ◽  
Sung-Hoon Kim ◽  
Yoon Se Lee ◽  
Seung-Ho Choi ◽  
Seung-Woo Ku ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Arrival Time ◽  
Characteristic Curve ◽  
Sudden Change ◽  
Area Under The Curve ◽  
Sudden Increase ◽  
Maximum Slope ◽  
Pulse Arrival Time ◽  
Before And After ◽  
Pulse Arrival

Background Laryngeal microsurgery (LMS) is often accompanied by a sudden increase in blood pressure (BP) during surgery because of stimulation around the larynx. This sudden change in the hemodynamic status is not immediately reflected in a casual cuff-type measurement that takes intermittent readings every 3 to 5 min. Objective This study aimed to investigate the potential of pulse arrival time (PAT) as a marker for a BP surge, which usually occurs in patients undergoing LMS. Methods Intermittent measurements of BP and electrocardiogram (ECG) and photoplethysmogram (PPG) signals were recorded during LMS. PAT was defined as the interval between the R-peak on the ECG and the maximum slope on the PPG. Mean PAT values before and after BP increase were compared. PPG-related parameters and the correlations between changes in these variables were calculated. Results BP surged because of laryngoscopic manipulation (mean systolic BP [SBP] from 115.3, SD 21.4 mmHg, to 159.9, SD 25.2 mmHg; P<.001), whereas PAT decreased significantly (from mean 460.6, SD 51.9 ms, to 405.8, SD 50.1 ms; P<.001) in most of the cases. The change in SBP showed a significant correlation with the inverse of the PAT (r=0.582; P<.001). Receiver-operating characteristic curve analysis indicated that an increase of 11.5% in the inverse of the PAT could detect a 40% increase in SBP, and the area under the curve was 0.814. Conclusions During LMS, where invasive arterial catheterization is not always possible, PAT shows good correlation with SBP and may, therefore, have the potential to identify abrupt BP surges during laryngoscopic manipulations in a noninvasive manner.

The Study of Dynamic Response to Acute Hemorrhage by Pulse Spectrum Analysis

2006 ◽  
Vol 34 (03) ◽  
pp. 449-460 ◽  
Author(s):  
Yu Hsin Chang ◽  
Chia I Tsai ◽  
Jaung Geng Lin ◽  
Yue Der Lin ◽  
Tsai Chung Li ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Steady State ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Spectrum Analysis ◽  
Pulse Spectrum ◽  
Acute Hemorrhage ◽  
Arterial Blood ◽  
Percentage Difference ◽  
Before And After

Traditional Chinese Medicine (TCM) holds that Blood and Qi are fundamental substances in the human body for sustaining normal vital activity. The theory of Qi, Blood and Zang-Fu contribute the most important theoretical basis of human physiology in TCM. An animal model using conscious rats was employed in this study to further comprehend how organisms survive during acute hemorrhage by maintaining the functionalities of Qi and Blood through dynamically regulating visceral physiological conditions. Pulse waves of arterial blood pressure before and after the hemorrhage were taken in parallel to pulse spectrum analysis. Percentage differences of mean arterial blood pressure and harmonics were recorded in subsequent 5-minute intervals following the hemorrhage. Data were analyzed using a one-way analysis of variance (ANOVA) with Duncan's test for pairwise comparisons. Results showed that, within 30 minutes following the onset of acute hemorrhage,the reduction of mean arterial blood pressure was improved from 62% to 20%. Throughout the process, changes to the pulse spectrum appeared to result in a new balance over time. The percentage differences of the second and third harmonics, which were related to kidney and spleen, both increased significantly than baseline and towards another steady state. Apart from the steady state resulting from the previous stage, the percentage difference of the 4th harmonic decreased significantly to another steady state. The observed change could be attributed to the induction of functional Qi, and is a result of Qi-Blood balancing activity that organisms hold to survive against acute bleeding.

Cardiopulmonary reflexes and blood pressure in exercising sinoaortic-denervated dogs

1984 ◽  
Vol 57 (5) ◽  
pp. 1417-1421 ◽  
Author(s):  
D. A. Daskalopoulos ◽  
J. T. Shepherd ◽  
S. C. Walgenbach
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Vagal Afferents ◽  
Systemic Resistance ◽  
Vigorous Exercise ◽  
Arterial Blood ◽  
Resistance Vessels ◽  
Before And After ◽  
Cervical Vagotomy ◽  
Cardiopulmonary Receptors

To examine the role of cardiopulmonary receptors in arterial blood pressure regulation during and after exercise, conscious dogs with chronic sinoaortic denervation were subjected to 12 min of light exercise and 12 min of exercise that increased in severity every 3 min. Hemodynamic measurements were made before and after interruption of cardiopulmonary afferents by bilateral cervical vagotomy. During both exercise protocols, after an initial transient decrease, the arterial blood pressure remained close to resting values before and after vagotomy. On cessation of the graded exercise, the arterial blood pressure did not change before, but a rapid and sustained increase in pressure occurred after vagotomy. At the time of this increase the cardiac output and heart rate were returning rapidly to the resting level. The study demonstrates that in the chronic absence of arterial baroreflexes, vagal afferents prevent a rise in arterial blood pressure after vigorous exercise presumably by the action of cardiopulmonary receptors causing a rapid dilatation of systemic resistance vessels.

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