Non-invasive beat-to-beat cardiac output monitoring by an improved method of transthoracic bioimpedance measurement

Fortin, Jürgen; Habenbacher, W.; Heller, Alfred; Häcker, Anna-Luisa; Grüllenberger, R.; Innerhofer, J.; Passath, H.; Wagner, Ch.; Haitchi, Gerhard; Flotzinger, Doris; Pacher, Richard; Wach, Paul

doi:10.1016/j.compbiomed.2005.06.001

Cited by 201 publications

(160 citation statements)

References 19 publications

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“…These BP values were automatically and continuously corrected to oscillometric BP values obtained at the contralateral arm (brachial artery). An estimate of real-time beat-to-beat SV was derived using an improved method of transthoracic impedance cardiography (ICG) (15,16,18). ICG utilizes changes in thoracic electrical impedance to estimate changes in blood volume in the aorta and changes in fluid volume in the thorax (16).…”

Section: Methodsmentioning

confidence: 99%

Heart rate variability and spontaneous baroreflex sequences in supine healthy volunteers subjected to nasal positive airway pressure

Valipour¹,

Schneider²,

Kössler³

et al. 2005

Journal of Applied Physiology

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. Heart rate variability and spontaneous baroreflex sequences in supine healthy volunteers subjected to nasal positive airway pressure. J Appl Physiol 99: [2137][2138][2139][2140][2141][2142][2143] 2005. First published July 7, 2005; doi:10.1152/japplphysiol.00003.2005.-To determine the dynamic effects of short-term nasal positive airway pressure (nPAP) on cardiovascular autonomic control, continuous recordings of noninvasively obtained hemodynamic measurements and heart rate variability (HRV) were obtained in 10 healthy subjects during frequency-controlled breathing (between 0.20 and 0.24 Hz) in supine posture under different pressures of nPAP ranging from 3 to 20 cmH 2O. HRV was assessed using spectral analysis of the R-R interval. The slope of the regression line between spontaneous systolic blood pressure and pulse interval changes was taken as an index of the sensitivity of arterial baroreflex modulation of heart rate (sequence method). Application of nPAP resulted in a pressure-dependent decrease of cardiac output and stroke volume (P Ͻ 0.05, ANOVA) and in an increase in total peripheral resistance (P Ͻ 0.03, ANOVA). Hemodynamic changes under increasing nPAP were accompanied by a decrease in total power of HRV despite mean R-R interval remaining unchanged. The overall decrease in HRV was accompanied by a reduction across all frequency bands when absolute units were used (P Ͻ 0.01). When the power of low frequency and high frequency was calculated in normalized units, a diminished high frequency and an increased low-to-high frequency ratio were observed (P Ͻ 0.05). Compared with low levels of nPAP, pressure levels of Ͼ10 cmH 2O were associated with a significant decline in the mean slope of spontaneous baroreceptor sequences (P Ͻ 0.04). These findings indicate that short-term administration of nPAP in normal subjects exerts significant alterations in R-R interval variability and spontaneous baroreflex modulation of heart rate. cardiac output; cardiovascular autonomic control; heart-lung interaction RESPIRATION SIGNIFICANTLY INFLUENCES autonomic cardiovascular control (12). During normal breathing, oscillatory changes of left ventricular stroke volume (SV) and arterial blood pressure (BP) are sensed by baroreceptors, which provoke parallel R-R interval changes by means of baroreflex physiology (27). Hemodynamic oscillations during normal (negative pressure) respiration are predominantly due to changes in intrathoracic pressure (ITP) (30). However, little is known about the effects of augmented positive ITP, which occurs with positive airway pressure (PAP) ventilation, on cardiovascular autonomic control. The application of PAP, both invasively or noninvasively, increases ITP and may result in a reduction in cardiac filling pressures (23,29,37,43). A reduction in cardiac filling pressures associated with PAP (or positive end-expiratory pressure) may induce a compensatory increase in vascular resistance to maintain systemic arterial pressure in the face of a reduced cardiac output (CO) (5, 41). The increase in...

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Section: Methodsmentioning

confidence: 99%

Heart rate variability and spontaneous baroreflex sequences in supine healthy volunteers subjected to nasal positive airway pressure

Valipour¹,

Schneider²,

Kössler³

et al. 2005

Journal of Applied Physiology

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“…The method is based on concentrically interlocking control loops for correct long-term tracing of finger BP and delivers, in contrast to intermittent set point re-adjustments of the conventional vascular unloading technique, BP without interruptions (Fortin et al, 2006a). For thoracic impedance measurement, three CNSystems shortband electrodes (two electrode bands set at a predefined distance onto a common adhesive medium; sampling rate = 500 Hz, I eff < 400 A, f = 45 kHz, Z0,range = 10-75 , dZ/dt = ±10 /s) were placed onto the participant: one placed at the nape of the neck close to the glottis, two others placed on the thorax close to the xiphoid (see Fortin et al, 2006b). …”

Section: Physiological Recordingmentioning

confidence: 99%

I got it! Transient cardiovascular response to the perception of humor

Lackner

Weiss

Schulter

et al. 2013

Biological Psychology

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a b s t r a c tThe aim of the present study was to examine the transient cardiovascular response to the perception of humor, that is, the impact of the cognitive process of insight as well as the modulation of the response by the affective appraisal of the humor. To this end transient heart rate, stroke volume, cardiac output, and blood pressure responses were obtained in the immediate context of detecting the punch line in cartoons. Fine-grained analysis of the transient behavior of cardiovascular variables during viewing the cartoons was contrasted to non-humorous cartoon-like pictures. The detection of a punch line was accompanied by relative heart rate acceleration in conjunction with increased cardiac output, which was more pronounced the more amusing the cartoons were perceived. These results provide first evidence of the usefulness of cardiovascular variables for detecting the moment of insight and the quantification of the size of the emotional response accompanying it.

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“…An increase or a decrease of beat-to-beat RR-interval and SBP in the same direction for at least three cardiac cycles was used to describe the steepness of the regression line [12].…”

Section: Heart Rate and Blood Pressure Variabilitymentioning

confidence: 99%

“…TFM s ECG/impedance electrodes were positioned at the neck and thoracic regions, the latter at the midclavicular line at the xiphoid process level [12]. TPR was calculated as mean arterial blood pressure/ cardiac output and mean arterial pressure from (SBP-DBP)/3)þDBP.…”

Section: Hemodynamic Monitoringmentioning

confidence: 99%

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Does mental arithmetic before head up tilt have an effect on the orthostatic cardiovascular and hormonal responses?

et al. 2011

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Passive head up tilt (HUT) and mental arithmetic (MA) are commonly used for providing mental and orthostatic challenges, respectively. In animal experiments, even a single exposure to a stressor has been shown to modify the response to subsequent stress stimulus. We investigated whether MA applied before HUT elicits synergistic responses in orthostatic heart rate (HR), cardiac output (CO), heart rate variability and arterial blood pressure. The 15 healthy young males were subjected to two randomized protocols: (a) HUT and (b) HUT preceded by MA, with sessions randomized and Z2 weeks apart. Beat to beat continuous hemodynamic variables were measured and saliva samples taken for hormonal assay. HUT alone increased HR from 5977 (baseline) to 80710 bpm (mean7SD) and mean blood pressure (MBP) from 88710 to 91714 mmHg. HUT results after MA were not different from those with HUT alone. The activity of alpha amylase showed differences during the experiments irrespective of the protocols. We conclude that mental challenge does not affect orthostatic cardiovascular responses when applied before; the timing of mental loading seems to be critical if it is intended to alter cardiovascular responses to upright standing.

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Non-invasive beat-to-beat cardiac output monitoring by an improved method of transthoracic bioimpedance measurement

Cited by 201 publications

References 19 publications

Heart rate variability and spontaneous baroreflex sequences in supine healthy volunteers subjected to nasal positive airway pressure

Heart rate variability and spontaneous baroreflex sequences in supine healthy volunteers subjected to nasal positive airway pressure

I got it! Transient cardiovascular response to the perception of humor

Does mental arithmetic before head up tilt have an effect on the orthostatic cardiovascular and hormonal responses?

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