scholarly journals Blood pressure variability from intra-arterial recordings in humans

2019 ◽  
Author(s):  
Farhan Adam Mukadam ◽  
Naveen Gangadharan ◽  
Bowya Baskaran ◽  
S Baskaran ◽  
Kandasamy Subramani ◽  
...  
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Dynamic Characteristics ◽  
Diastolic Pressure ◽  
Single Point ◽  
Power Spectral ◽  
Total Magnitude ◽  
Mayer Wave ◽  
Invasive Techniques ◽  
Respiratory Variability

AbstractSystolic and diastolic blood pressures are reported as single point values by the non-invasive techniques used in clinical practice, while, in fact, they are highly varying signals. The objective of this study was to document the magnitude of variation of systolic and diastolic pressures over a few minutes by analysing intra-arterial pressure recordings made in 51 haemodynamically stable patients in an intensive care unit. Intra-arterial pressure data were acquired by a validated data acquisition system. Fast-Flush test was performed and the dynamic characteristics of the catheter transducer system namely natural frequency and damping co-efficient were calculated. Only those recordings with acceptable dynamic characteristics were included in the analysis. Power spectral calculation using the Discrete Fourier transform (DFT) of the pressure recording revealed two frequency peaks below the peak at heart rate. The lower and higher frequency peaks below the heart rate peak are referred to as Mayer and Traube waves in this study. Mayer wave peaks were observed in DFT spectra of 49 out of 51 patients. The Mayer wave frequency peaks ranged between 0.045 Hz to 0.065 Hz in 41 out of 51 patients. The frequency of Traube waves or the respiratory variations was more than 0.14 Hz. Three categories of systolic and diastolic pressure variabilities namely beat-to-beat variability, Respiratory variability (Traube wave amplitude) and Total magnitude of variation are reported for all 51 patients. The mean systolic and diastolic pressure variations (in a period of about 10 minutes) in the study sample were 21 ± 9 mm Hg and 14 ± 5 mm Hg respectively. Given the magnitude of systolic and diastolic pressure variations over a few minutes, the validity of reporting single point values for these pressures and using single point cut-offs for diagnosis and treatment of hypertension must be re-evaluated.

Arterial pressure-flow relations in the awake standing dog

1975 ◽  
Vol 229 (5) ◽  
pp. 1261-1270 ◽  
Author(s):  
W Enrlich ◽  
FV Schrijen ◽  
TA Solomon ◽  
E Rodriguez-Lopez ◽  
RL Riley
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Rate Increase ◽  
Diastolic Pressure ◽  
Aortic Pressure ◽  
Left Ventricular ◽  
Right Atrial ◽  
Heart Rate Increase ◽  
Underlying Mechanisms ◽  
The Right

The transient circulatory changes following paced heart rate increase are reported from 133 trials with 6 unanesthetized dogs with chronically implanted monitoring devices for heart rate, cardiac output, aortic blood pressure, and mean right atrial pressure. In 62 trials with 2 of the dogs, pulmonary artery, and left ventricular end-diastolic pressure, as well as left ventricular dP/dt were also studied. The sequence of changes in pressures and flows is analyzed in terms of probable underlying mechanisms, particularly with respect to the nature of vascular resistances. The rise in aortic pressure and flow during the first 3 s of paced heart rate increase, before arterial stretch receptor reflexes become active, is more consistent with an effective downstream pressure of about 49 mmHg, presumably at the arteriolar level, than with an effective downstream pressure close to 0 mmHg at the right atrial level. In the pulmonary circulation where vascular reflex effects are less prominent, the pattern of pulmonary arterial pressure and flow for the entire 30 s of observation is consistent with an effective downstream pressure of 9 mmHg, presumably at the alveolar or pulmonary arteriolar level, rather than at the level of the left ventricular end-diastolic pressure.

scholarly journals Comparison of Haemodynamic Response to Intubation with KingVision and C-MAC Videolaryngoscope in Adults

2020 ◽  
Author(s):  
Prathima Padavarahalli Thammanna ◽  
Kavya Marasandra Seetharam ◽  
Tejesh Channasandra Anandaswamy ◽  
Prapti Rath ◽  
Geetha Chamanhalli Rajappa ◽  
...  
Keyword(s):  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
General Anaesthesia ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Haemodynamic Response ◽  
Time Points ◽  
Universal Device ◽  
Spss Software

Background: Videolaryngoscopes are now being advocated as the universal device for airway management due to their ability to provide an improved glottic visualisation. Due to their ability to see around the corners, they obviate the need to align the airway axes and thus may lead to less airway stimulation. This may result in less haemodynamic response during laryngoscopy and intubation. The present study was designed to compare the haemodynamic response to intubation with King Vision and C-MAC videolaryngoscopes. Methods: After obtaining informed consent, adults with unanticipated difficult intubation, scheduled to undergo surgery under general anaesthesia were randomised to be intubated with either King Vision (Group K) or C-MAC (Group C) videolaryngoscope. Following a standardised general anaesthesia induction protocol all subjects were intubated with the allocated videolaryngoscope and haemodynamic parameters (heart rate, systolic pressure, diastolic pressure and mean arterial pressure) were recorded at specific time points. Statistical analysis was done using the SPSS Software (version 18.0). Results: The changes in the heart rate, systolic pressure, diastolic pressure and mean arterial pressure following laryngoscopy and intubation with the allocated videolaryngoscope were statistically similar between the two groups at all time points. Conclusion: Haemodynamic responses to laryngoscopy and intubation with King Vision and C-MAC videolaryngoscopes were similar.

Diastolic pressure determines autonomic responses to pressure perturbation in humans

1989 ◽  
Vol 66 (2) ◽  
pp. 800-807 ◽  
Author(s):  
J. S. Sanders ◽  
D. W. Ferguson
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Sympathetic Nerve Activity ◽  
Diastolic Pressure ◽  
Human Subjects ◽  
Muscle Sympathetic Nerve Activity ◽  
Venous Pressure ◽  
Central Venous ◽  
Nerve Activity ◽  
Normal Human

Arterial baroreceptors reflexly regulate sympathetic and heart rate responses to alteration of blood pressure. The primary mechanical determinant of arterial baroreceptor activity in humans remains unclear. We examined the influence of systolic, diastolic, pulse, and mean arterial pressures on efferent muscle sympathetic nerve activity (MSNA, microneurography) and heart rate responses during perturbation of arterial pressure in 10 normal human subjects [age 25 +/- 2 (SE) yr]. We directly measured arterial pressure, heart rate, and MSNA during intravenous vasodilator infusion (nitroprusside, 6 +/- 1 micrograms.kg-1.min-1, n = 6; or hydralazine, 16 +/- 2 mg, n = 4) while central venous pressure was held constant by simultaneous volume expansion. Changes in arterial pressures were compared with changes in heart rate and MSNA over 3-min periods of vasodilator infusion during which we observed increases in systolic and pulse pressures with simultaneous decreases in mean and diastolic pressures. During vasodilator infusion, there were increases in systolic (124.2 +/- 2.1 to 131.7 +/- 2.9 Torr, P less than 0.001) and pulse pressures (57.0 +/- 2.2 to 72.7 +/- 2.7 Torr, P less than 0.001) although mean arterial pressure fell (88.0 +/- 2.6 to 80.4 +/- 2.7 Torr, P less than 0.001) because of decreases in diastolic pressure (67.2 +/- 3.0 to 59.0 +/- 2.7 Torr, P less than 0.001). The changes in arterial pressures were accompanied by simultaneous increases in heart rate (66.4 +/- 3.0 to 92.6 +/- 4.8 beats/min, P less than 0.001) and MSNA (327 +/- 59 to 936 +/- 171 U, P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Microgravity decreases heart rate and arterial pressure in humans

1996 ◽  
Vol 80 (3) ◽  
pp. 910-914 ◽  
Author(s):  
J. M. Fritsch-Yelle ◽  
J. B. Charles ◽  
M. M. Jones ◽  
M. L. Wood
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Cardiac Rhythm ◽  
Orthostatic Intolerance ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Microgravity Environment ◽  
Systematic Evaluation ◽  
Premature Ventricular Contractions ◽  
Cardiovascular Variables

Spaceflight causes adaptive changes in cardiovascular physiology, such as postflight orthostatic intolerance, that can have deleterious effects on astronauts. In-flight cardiovascular data are difficult to obtain, and results have been inconsistent. To determine normative in-flight changes in Shuttle astronauts, we measured heart rate, arterial pressure, and cardiac rhythm disturbances for 24-h periods before, during, and after spaceflight on Shuttle astronauts performing their normal routines. We found that heart rate, diastolic pressure, variability of heart rate and diastolic pressure, and premature ventricular contractions all were significantly reduced in flight. Systolic pressure and premature atrial contractions also tended to be reduced in flight. These data constitute the first systematic evaluation of in-flight changes in basic cardiovascular variables in Shuttle astronauts and suggest that a microgravity environment itself does not present a chronic stress to the cardiovascular system.

Analysis of afferent, central, and efferent components of the baroreceptor reflex in mice

2002 ◽  
Vol 283 (5) ◽  
pp. R1033-R1040 ◽  
Author(s):  
Xiuying Ma ◽  
Francois M. Abboud ◽  
Mark W. Chapleau
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Molecular Mechanisms ◽  
Diastolic Pressure ◽  
Logistic Function ◽  
Baroreceptor Reflex ◽  
Nerve Activity ◽  
Maximum Slope ◽  
Aortic Depressor Nerve ◽  
Pressure Threshold

Studies of genetically modified mice provide a powerful approach to investigate consequences of altered gene expression in physiological and pathological states. The goal of the present study was to characterize afferent, central, and efferent components of the baroreceptor reflex in anesthetized Webster 4 mice. Baroreflex and baroreceptor afferent functions were characterized by measuring changes in renal sympathetic nerve activity (RSNA) and aortic depressor nerve activity (ADNA) in response to nitroprusside- and phenylephrine-induced changes in arterial pressure. The data were fit to a sigmoidal logistic function curve. Baroreflex diastolic pressure threshold (Pth), the pressure at 50% inhibition of RSNA (Pmid), and baroreflex gain (maximum slope) averaged 74 ± 5 mmHg, 101 ± 3 mmHg, and 2.30 ± 0.54%/mmHg, respectively ( n = 6). The Pth, Pmid, and gain for the diastolic pressure-ADNA relation (baroreceptor afferents) were similar to that observed for the overall reflex averaging 79 ± 9 mmHg, 101 ± 4 mmHg, and 2.92 ± 0.53%/mmHg, respectively ( n = 5). The central nervous system mediation of the baroreflex and the chronotropic responsiveness of the heart to vagal efferent activity were independently assessed by recording responses to electrical stimulation of the left ADN and the peripheral end of the right vagus nerve, respectively. Both ADN and vagal efferent stimulation induced frequency-dependent decreases in heart rate and arterial pressure. The heart rate response to ADN stimulation was nearly abolished in mice anesthetized with pentobarbital sodium ( n = 4) compared with mice anesthetized with ketamine-acepromazine ( n = 4), whereas the response to vagal efferent stimulation was equivalent under both types of anesthesia. Application of these techniques to studies of genetically manipulated mice can be used to identify molecular mechanisms of baroreflex function and to localize altered function to afferent, central, or efferent sites.

Hemodynamic effects of angiotensin, norepinephrine, and bradykinin continuously measured in unanesthetized dogs

1961 ◽  
Vol 201 (1) ◽  
pp. 92-96 ◽  
Author(s):  
Irvine H. Page ◽  
Frederick Olmsted
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Diastolic Pressure ◽  
Pressor Response ◽  
Peripheral Resistance ◽  
Partial Recovery ◽  
Slight Rise ◽  
Abrupt Rise

Cardiac output, arterial pressure, heart rate and the derived functions, peripheral resistance and stroke volume, were registered continuously from intact, unanesthetized, unrestrained dogs. Isoleucyl5- or valyl5-angiotensin octapeptide caused output, heart rate and stroke volume to fall sharply when peripheral resistance rose. When infused for an hour, systolic and diastolic pressure remained elevated with unchanged infusion rate. Heart rate decreased in most animals, stroke volume and cardiac output fell, while peripheral resistance rose. Pentobarbital anesthesia increased somewhat the pressor response and decreased the bradycardia. Norepinephrine elicited, first, an abrupt rise in pressure and peripheral resistance, slight rise in heart rate and stroke volume. Arterial pressure then tended to stabilize, followed by a slow decrease associated with continued depression of cardiac output. Bradykinin caused fall in pressure, partial recovery, then further fall. Heart rate slowed, then rose. Cardiac output rose sharply during the initial fall in arterial pressure and remained elevated during the hypotensive response. Stroke volume was reduced during the initial fall but was reduced less during the rest of the response. Peripheral resistance was decreased sharply.

Acute manipulations of plasma volume alter arterial pressure responses during Valsalva maneuvers

1999 ◽  
Vol 86 (6) ◽  
pp. 1852-1857 ◽  
Author(s):  
Janice M. Fritsch-Yelle ◽  
Victor A. Convertino ◽  
Todd T. Schlegel
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Phase Ii ◽  
Plasma Volume ◽  
Diastolic Pressure ◽  
Valsalva Maneuver ◽  
Isotonic Saline ◽  
Systolic Pressure ◽  
Cardiovascular Responses ◽  
Phase Iii

The effects of changes in blood volume on arterial pressure patterns during the Valsalva maneuver are incompletely understood. In the present study we measured beat-to-beat arterial pressure and heart rate responses to supine Valsalva maneuvers during normovolemia, hypovolemia induced with intravenous furosemide, and hypervolemia induced with ingestion of isotonic saline. Valsalva responses were analyzed according to the four phases as previously described (W. F. Hamilton, R. A. Woodbury, and H. T. Harper, Jr. JAMA 107: 853–856, 1936; W. F. Hamilton, R. A. Woodbury, and H. T. Harper, Jr. Am. J. Physiol. 141: 42–50, 1944). Phase I is the initial onset of straining, which elicits a rise in arterial pressure; phase II is the period of straining, during which venous return is impeded and pressure falls (early) and then partially recovers (late); phase III is the initial release of straining; and phase IV consists of a rapid “overshoot” of arterial pressure after the release. During hypervolemia, early phase II arterial pressure decreases were significantly less than those during hypovolemia, thus making the response more “square.” Systolic pressure hypervolemic vs. hypovolemic falls were −7.4 ± 2.1 vs. −30.7 ± 7 mmHg ( P = 0.005). Diastolic pressure hypervolemic vs. hypovolemic falls were −2.4 ± 1.6 vs. −15.2 ± 2.6 mmHg ( P = 0.05). A significant direct correlation was found between plasma volume and phase II systolic pressure falls, and a significant inverse correlation was found between plasma volume and phase III-IV systolic pressure overshoots. Heart rate responses to systolic pressure falls during phase II were significantly less during hypovolemia than during hypervolemia (0.7 ± 0.2 vs. 2.82 ± 0.2 beats ⋅ min−1 ⋅ mmHg−1; P = 0.05) but were not different during phase III-IV overshoots. We conclude that acute changes in intravascular volume from hypovolemia to hypervolemia affect cardiovascular responses, particularly arterial pressure changes, to the Valsalva maneuver and should be considered in both clinical and research applications of this maneuver.

Power Spectral Analysis of Heart Rate and Arterial Pressure Variabilities as an Experimental and Clinical Tool

1991 ◽  
pp. 291-299
Author(s):  
A. Malliani ◽  
M. Pagani ◽  
F. Lombardi ◽  
G. Baselli ◽  
S. Cerutti
Keyword(s):  
Heart Rate ◽  
Spectral Analysis ◽  
Arterial Pressure ◽  
Power Spectral Analysis ◽  
Clinical Tool ◽  
Power Spectral

Dextran as a radioactive microsphere suspending agent: severe hypotensive effect in rat

1978 ◽  
Vol 235 (5) ◽  
pp. H587-H591
Author(s):  
S. F. Flaim ◽  
Z. Q. Morris ◽  
T. J. Kennedy
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Saline Solution ◽  
Diastolic Pressure ◽  
Isotonic Saline ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Cardiovascular Hemodynamics ◽  
Radioactive Microsphere ◽  
Dextran Solution

The effects of different commercially available radioactive microsphere suspending solutions were studied on the cardiovascular hemodynamics of male, Sprague-Dawley rats. Single left ventricular injections of carbonized radioactive microspheres (15 +/- 5 micron diam) totaling 850,000 spheres, suspended in 10% dextran (mol wt, 73,000) solution with Tween, caused reductions in arterial pressure (control, 101; postinjection, 74 mmHg; P less than 0.001), with no change in heart rate. Identical injections made with isotonic saline solution plus Tween had no effect on either heart rate or arterial pressure. Independent studies were conducted to examine the effects of 1-ml injections of four suspending solutions without microspheres on the cardiovascular hemodynamics of rats. Isotonic saline had no hemodynamic effect, and isotonic saline plus Tween decreased only heart rate. Ten percent dextran soluton with Tween decreased arterial pressure, heart rate, peak left ventricular systolic pressure, and left ventricular end-diastolic pressure. Similar changes occurred when dextran solution without Tween was administered. These data demonstrate that 10% dextran solution used as a microsphere suspending agent induces a severe hypotensive response in rats. Furthermore, injections of up to 850,000 microspheres in isotonic saline solution do not alter arterial pressure in the rat.

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