Impedance Cardiography

Cybulski, Gerard

doi:10.1007/978-3-642-11987-3_2

Cited by 8 publications

(3 citation statements)

References 68 publications

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“…We determined the pre-ejection period (PEP) and left ventricular ejection time (ET) from the ECG findings and the derivative signal of ICG for systolic interval analysis (Cybulski, 2011). The PEP was determined as the interval between the Q waves on ECG to point B which is associated with opening of the aortic valve at the first derivative thoracic bioimpedance.…”

Section: Discussionmentioning

confidence: 99%

“…The PEP describes the sum of the electromechanical delay and isovolumetric contraction and ET describes the interval between the opening and closing of the aortic valve (Boudoulas, 1986;Cybulski, 2011). Previous findings have shown that PEP is prolonged and ET is shortened in the upright position (Chan et al, 2007;Cybulski et al, 2004;Lewis et al, 1977;STAFFORD et al, 1970).…”

Section: Systolic Time Intervalsmentioning

confidence: 97%

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Effects of trunk posture in Fowler's position on hemodynamics

Kubota

Endo

Kubota

et al. 2015

Autonomic Neuroscience

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We speculated that stroke volume would be higher and heart rate would be lower when the head and upper trunk were mainly upright in the Fowler's position. We therefore analyzed the effects of three trunk postures in Fowler's position on heart rate, blood pressure and circulatory volume. Heart rate (HR), blood pressure (BP), stroke volume (SV), cardiac output (Q), systemic vascular resistance (SVR), ejection time (ET) and pre-ejection period (PEP) were measured in 10 healthy male volunteers (mean age ± SEM, 20.7 ± 0.5 y; range, 19-23 y) while in three trunk postures in Fowler's position. Stroke volume and Q were measured using impedance cardiography. The three trunk postures were 30° of lower and upper trunk inclination (WT30°), 30° and 60° of lower and upper trunk inclination (UT 60°), respectively and 60° of upper and lower trunk inclination (WT60°). Both SV and ET were significantly higher and HR and PEP were lower at UT60° than at WT60° (p < 0.01) whereas these values did not significantly differ between WT30° and UT60° (p > 0.05). None of Q, SVR and BP significantly differed among the three conditions (p > 0.05). These findings suggested that SV and preload are higher when the upper trunk is upright (UT60°) than when the entire trunk is upright (WT60°) while in Fowler's position. In addition, Q might be maintained without increasing HR through vagal withdrawal when only the upper trunk is upright in healthy young males in Fowler's position.

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Section: Discussionmentioning

confidence: 99%

Section: Systolic Time Intervalsmentioning

confidence: 97%

Effects of trunk posture in Fowler's position on hemodynamics

Kubota

Endo

Kubota

et al. 2015

Autonomic Neuroscience

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“…The measurement of electrical resistance, or impedance, in the chest throughout the cardiac cycle generates a wave form (Z) based on the path of electrical vectors. Taking the derivative of the Z wave over ventricular ejection time will generate a change in blood volume flowing through the chest, which is the stroke volume 7. From stroke volume, cardiac output can be extrapolated using the patient’s heart rate, or more simply by measuring the stroke volume during the course of 1 minute, creating a more accurate measurement of minute to minute cardiac output, given that the stroke volume multiplied by an instantaneous heart rate, which can vary between 70 and 100 beats per minute (bpm) on telemetry monitors in a critically ill patient, will also vary.…”

Section: Introductionmentioning

confidence: 99%

The utility of impedance cardiography in hemodynamic monitoring of patients with sepsis

Butz

Shan

Samayoa

et al. 2019

Trauma Surg Acute Care Open

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BackgroundCommonly used biochemical indicators and hemodynamic and physiologic parameters of sepsis vary with regard to their sensitivity and specificity to the diagnosis. The aim of this preliminary study was to evaluate non-invasive impedance cardiography as a monitoring tool of the hemodynamic status of patients with sepsis throughout their initial volume resuscitation to explore the possibility of identifying additional measurements to be used in the future treatment of sepsis.MethodsNine patients who presented to the emergency room and received a surgical consultation during a 3-month period in 2016, meeting the clinical criteria of sepsis defined by systemic inflammatory response syndrome in the 2012 Surviving Sepsis Campaign Guidelines, were included in this study. We applied cardiac impedance monitors to each patient’s anterior chest and neck and obtained baseline recordings. Measurements were taken at activation of the sepsis alert and 1 hour after fluid resuscitation with 2 L of intravenous crystalloid solution.ResultsNine patients met the inclusion criteria. The mean age was 60±17 years and two were female; eight were febrile, five were hypotensive, four were tachycardic, seven were treated for infection, and six had positive blood cultures. Hemodynamic parameters at presentation and 1 hour after fluid resuscitation were heart rate (beats per minute) (97±13 and 93±18; p=0.23), mean arterial pressure (mm Hg) (81±13 and 85±14; p=0.55), systemic vascular resistance (dyne-s/cm−5) (861±162 and 1087±272; p=0.04), afterload measured as systemic vascular resistance index (dyne-s/cm−5/m2) (1813±278 and 2283±497; p=0.04), and left cardiac work index (kg*m/m2) (3.6±1.4 and 3.3±1.3; p=0.69).DiscussionThrough measuring a patient’s systemic vascular resistance and systemic vascular resistance index (afterload), statistical significance is achieved after intervention with a 2 L crystalloid bolus. This suggests that, along with clinical presentation and biochemical markers, impedance cardiography may show utility in providing supporting hemodynamic data to trend resuscitative efforts in patients with sepsis.Level of evidenceLevel IV.

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