Finger Arterial versus Intrabrachial Pressure and Continuous Cardiac output during Head-up Tilt Testing in Healthy Subjects

1996 ◽  
Vol 91 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Wilbert T. Jellema ◽  
Ben P. M. Imholz ◽  
Jeroen Van Goudoever ◽  
Karel H. Wesseling ◽  
Johannes J. Van Lieshout
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Healthy Subjects ◽  
Pulse Contour Analysis ◽  
Pulse Contour ◽  
Mean Blood Pressure ◽  
Contour Analysis ◽  
Head Up Tilt ◽  
The Difference

1. The aims of this study were to determine the clinical feasibility of continuous, non-invasive Finapres recordings as a replacement for intrabrachial pressure during a 30 min head-up tilt, and the reliability of continuous cardiac output computation by pulse contour analysis from the finger arterial versus the brachial waveform. 2. In eight healthy subjects a 30 min 70° passive head-up tilt was performed. Finger arterial (FINAP) and intrabrachial (IAP) pressures were measured simultaneously. Beat-to-beat changes in stroke volume were computed using a pulse contour algorithm. 3. Accuracy (the group-averaged FINAP—IAP difference) and precision (the SD of the difference) of Finapres measurements were 4 and 9 mmHg for systolic blood pressure, −5 and 9 mmHg for mean blood pressure and −5 and 9 mmHg for diastolic blood pressure. 4. The time course of the FINAP—IAP differences during head-up tilt showed a linear trend (P < 0.001 for all pressure levels). Averaged for the group, the difference increased 7 mmHg for mean blood pressure. The difference in stroke volume computed from FINAP and IAP was 0.3 ± 5% (mean ± SD), and independent of the duration of the tilt (P > 0.05). This difference did not change at low blood pressure levels (0.5 ± 6%). 5. The qualitative performance of the Finapres allows it to be used in the clinical setting as a monitor of sudden changes in blood pressure induced by a 30 min head-up tilt. Relative changes in stroke volume, as obtained by pulse contour analysis of the finger arterial waveform, closely follow intrabrachial values during long-duration head-up tilt and associated arterial hypotension.

Dynamics of Circulatory Adjustments to Head-Up Tilt and Tilt-Back in Healthy and Sympathetically Denervated Subjects

1998 ◽  
Vol 94 (4) ◽  
pp. 347-352 ◽  
Author(s):  
W. Wieling ◽  
J. J. Van Lieshout ◽  
A. D. J. Ten Harkel
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Healthy Subjects ◽  
Mean Blood Pressure ◽  
Head Up Tilt ◽  
Change In Mean

1. The initial circulatory adjustments induced by head-up tilt and tilt-back were investigated in six healthy subjects (aged 30–58 years) and six patients with orthostatic hypotension due to pure autonomic failure (aged 33–65 years). 2. Continuous responses of finger arterial pressure and heart rate were recorded by Finapres. A pulse contour algorithm applied to the arterial pressure waveform was used to compute stroke volume responses. 3. In the healthy subjects, head-up tilt induced gradual circulatory adjustments. After 1 min upright stroke volume and cardiac output had decreased by 39 ± 9% and 26 ± 10% respectively. Little change in mean blood pressure at heart level (+1 ± 7 mmHg) indicated that systemic vascular resistance had increased by 39 ± 24%. The gradual responses to head-up tilt contrasted with the pronounced and rapid circulatory responses upon tilt-back. After 2–3 s a rapid increase in stroke volume (from 62 ± 8% to 106 ± 10%) and cardiac output (from 81 ± 11% to 118 ± 20%) was observed with an overshoot of mean arterial pressure above supine control values of 16 ± 3 mmHg at 7 s. In the patients a progressive fall in blood pressure on head-up tilt was observed. After 1 min upright mean blood pressure had decreased by 59 ± 8 mmHg. No change in systemic vascular resistance and a larger decrease in stroke volume (60 ± 7%) and cardiac output (53 ± 8%) were found. On tilt-back a gradual recovery of blood pressure was observed. 4. In healthy humans upon head-up tilt neural compensatory mechanisms are very effective in maintaining arterial pressure at heart level. The gradual circulatory adjustments to head-up tilt in healthy subjects contrast with the pronounced and abrupt circulatory changes on tilt-back. In patients with a lack of neural circulatory reflex adjustments, gradual blood pressure decreases to head-up tilt and gradual increases to tilt-back are observed.

Mechanisms underlying the impairment in orthostatic tolerance after nocturnal recumbency in patients with autonomic failure

2001 ◽  
Vol 101 (6) ◽  
pp. 609-618 ◽  
Author(s):  
Stefano OMBONI ◽  
Adrianus A.J. SMIT ◽  
Johannes J. VAN LIESHOUT ◽  
Jos J. SETTELS ◽  
Gerard J. LANGEWOUTERS ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Orthostatic Hypotension ◽  
Peripheral Resistance ◽  
Pulse Contour Analysis ◽  
Pressure Profile ◽  
Neurogenic Orthostatic Hypotension ◽  
Contour Analysis ◽  
Standing Blood Pressure

In the present study, we have assessed in patients with neurogenic orthostatic hypotension the haemodynamics underlying the reduced tolerance to standing after prolonged recumbency at night. In 10 patients with neurogenic orthostatic hypotension (age 33-68 years), of which seven were being treated with fludrocortisone and/or sleeping in the 12° head-up tilt position, 24h continuous non-invasive finger blood pressure was recorded by a Portapres device. Beat-to-beat blood pressure, heart rate, stroke volume, cardiac output and total peripheral vascular resistance obtained by pulse contour analysis were assessed during 5min of standing in the evening (at 22.30 hours) and in the morning (at 06.30hours). On average, the inverse of the normal 24h blood pressure profile was found, with a large diversity in blood pressure profiles among patients. Supine blood pressure values were similar, but standing blood pressure values were lower in the morning than in the evening (P < 0.01). This resulted from larger falls in stroke volume and cardiac output upon standing in the morning compared with the evening, while total peripheral resistance did not change. There was no relationship between the decrease in body weight during the night (mean 0.9kg; range 0.2-1.6kg) and the evening-morning difference in standing blood pressure. We conclude that, in patients with neurogenic orthostatic hypotension, the impaired tolerance to standing in the morning is due to larger falls in stroke volume and cardiac output. Not only nocturnal polyuria, but also a redistribution of body fluid, are likely mechanisms underlying the pronounced decreases in stroke volume and cardiac output after prolonged recumbency at night.

scholarly journals Cardiac output by pulse contour analysis does not match the increase measured by rebreathing during human spaceflight

2017 ◽  
Vol 123 (5) ◽  
pp. 1145-1149 ◽  
Author(s):  
Richard L. Hughson ◽  
Sean D. Peterson ◽  
Nicholas J. Yee ◽  
Danielle K. Greaves
Keyword(s):  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Pulse Contour Analysis ◽  
Pulse Contour ◽  
Alternative Methods ◽  
Contour Analysis ◽  
Windkessel Model ◽  
Human Spaceflight ◽  
Arterial Blood

Pulse contour analysis of the noninvasive finger arterial pressure waveform provides a convenient means to estimate cardiac output (Q̇). The method has been compared with standard methods under a range of conditions but never before during spaceflight. We compared pulse contour analysis with the Modelflow algorithm to estimates of Q̇ obtained by rebreathing during preflight baseline testing and during the final month of long-duration spaceflight in nine healthy male astronauts. By Modelflow analysis, stroke volume was greater in supine baseline than seated baseline or inflight. Heart rate was reduced in supine baseline so that there were no differences in Q̇ by Modelflow estimate between the supine (7.02 ± 1.31 l/min, means ± SD), seated (6.60 ± 1.95 l/min), or inflight (5.91 ± 1.15 l/min) conditions. In contrast, rebreathing estimates of Q̇ increased from seated baseline (4.76 ± 0.67 l/min) to inflight (7.00 ± 1.39 l/min, significant interaction effect of method and spaceflight, P < 0.001). Pulse contour analysis utilizes a three-element Windkessel model that incorporates parameters dependent on aortic pressure-area relationships that are assumed to represent the entire circulation. We propose that a large increase in vascular compliance in the splanchnic circulation invalidates the model under conditions of spaceflight. Future spaceflight research measuring cardiac function needs to consider this important limitation for assessing absolute values of Q̇ and stroke volume. NEW & NOTEWORTHY Noninvasive assessment of cardiac function during human spaceflight is an important tool to monitor astronaut health. This study demonstrated that pulse contour analysis of finger arterial blood pressure to estimate cardiac output failed to track the 46% increase measured by a rebreathing method. These results strongly suggest that alternative methods not dependent on pulse contour analysis are required to track cardiac function in spaceflight.

scholarly journals Noninvasive cardiac output measurement in orthostasis: pulse contour analysis compared with acetylene rebreathing

1999 ◽  
Vol 87 (6) ◽  
pp. 2266-2273 ◽  
Author(s):  
W. J. Stok ◽  
R. C. O. Stringer ◽  
J. M. Karemaker
Keyword(s):  
Cardiac Output ◽  
Reference Method ◽  
Pulse Contour Analysis ◽  
Pulse Contour ◽  
Upright Posture ◽  
Transmission Line Model ◽  
Contour Analysis ◽  
Output Measurement ◽  
Noninvasive Cardiac Output ◽  
Head Up Tilt

We tested the reliability of noninvasive cardiac output (CO) measurement in different body positions by pulse contour analysis (COpc) by using a transmission line model (K. H. Wesseling, B. De Wit, J. A. P. Weber, and N. T. Smith. Adv. Cardiol. Phys.5, Suppl. II: 16–52, 1983). Acetylene rebreathing (COrebr) was used as a reference method. Twelve subjects (age 21–34 yr) were studied: 1) six in whom COrebr and COpc were measured in the standing and 6° head-down tilt (HDT) postures and 2) six in whom CO was measured in the 30° HDT, supine, 30° head up-tilt (HUT), and 70° HUT postures on a tilt table. The COrebr-to-COpcratio in (near) the supine position during rebreathing was used as the calibration factor for COpcmeasurements. Calibrated COpc(COcal sup) consistently overestimated CO in the upright posture. The drop in CO with upright posture was underestimated by ∼50%. COcal sup and COrebr values did not differ in the 30° HDT position. Changes in the COrebr-to-COpcratio are highly variable among subjects in response to a change in posture. Therefore, COpc must be recalibrated for each subject in each posture.

scholarly journals Incorporating pulse wave velocity into model-based pulse contour analysis method for estimation of cardiac stroke volume

2020 ◽  
Vol 195 ◽  
pp. 105553
Author(s):  
Rachel Smith ◽  
Joel Balmer ◽  
Christopher G. Pretty ◽  
Tashana Mehta-Wilson ◽  
Thomas Desaive ◽  
...  
Keyword(s):  
Stroke Volume ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Pulse Wave ◽  
Pulse Contour Analysis ◽  
Pulse Contour ◽  
Analysis Method ◽  
Contour Analysis ◽  
Model Based ◽  
Cardiac Stroke Volume
Sign in / Sign up

Export Citation Format

Share Document