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Kolomeyets NL, Ivonin AG, Peshkin EA, Roshchevskaya IM. Bioelectrical Impedance of the Left Ventricular Myocardium, Lung in Rats after Forced Swimming Training and Subsequent Detraining. J EVOL BIOCHEM PHYS+ 2023. [DOI: 10.1134/s0022093023010064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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Do Cardiovascular Responses to Active and Passive Coping Tasks predict Future Blood Pressure over a 10-Month Later? SPANISH JOURNAL OF PSYCHOLOGY 2016; 19:E10. [DOI: 10.1017/sjp.2016.5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractThe study examined whether cardiovascular responses to active or passive coping tasks and single or multiple tasks predicted changes in resting blood pressure (BP) over a ten-month period. Heart rate (HR), BP, cardiac output (CO), and total peripheral resistance (TPR) were measured at rest, and during mental stress tests (mental arithmetic, speech, and cold pressor tasks). A total of 104 eligible participants participated in the initial study, and 77 (74.04%) normotensive adult participants’ resting BP were re-evaluated at ten-month follow-up. Regression analyses indicated that after adjustment for baseline BP, initial age, gender, body mass index, family history of cardiovascular disease, and current cigarette smoking, heighted systolic blood pressure (SBP) and HR responses to an active coping task (mental arithmetic) were associated with increased future SBP (ΔR2 = .060, ΔR2 = .045, respectively). Further, aggregated SBP responsivity (over the three tasks) to the predictor models resulted in significant, but smaller increases in ΔR2 accounting for .040 of the variance of follow-up SBP. These findings suggest that cardiovascular responses to active coping tasks predict future SBP. Further, compared with single tasks, the findings revealed that SBP responses to three tasks were less predictive compared to an individual task (i.e., mental arithmetic). Of importance, hemodynamic reactivity (namely CO and TPR) did not predict future BP suggesting that more general psychophysiological processes (e.g., inflammation, platelet aggregation) may be implicated, or that BP, but not hemodynamic reactivity may be a marker of hypertension.
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Blohm ME, Obrecht D, Hartwich J, Mueller GC, Kersten JF, Weil J, Singer D. Impedance cardiography (electrical velocimetry) and transthoracic echocardiography for non-invasive cardiac output monitoring in pediatric intensive care patients: a prospective single-center observational study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:603. [PMID: 25407329 PMCID: PMC4261789 DOI: 10.1186/s13054-014-0603-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 10/20/2014] [Indexed: 11/23/2022]
Abstract
Introduction Electrical velocimetry (EV) is a type of impedance cardiography, and is a non-invasive and continuously applicable method of cardiac output monitoring. Transthoracic echocardiography (TTE) is non-invasive but discontinuous. Methods We compared EV with TTE in pediatric intensive care patients in a prospective single-center observational study. Simultaneous, coupled, left ventricular stroke volume measurements were performed by EV using an Aesculon® monitor and TTE (either via trans-aortic valve flow velocity time integral [EVVTI], or via M-mode [EVMM]). H0: bias was less than 10% and the mean percentage error (MPE) was less than 30% in Bland–Altman analysis between EV and TTE. If appropriate, data were logarithmically transformed prior to Bland–Altman analysis. Results A total of 72 patients (age: 2 days to 17 years; weight: 0.8 to 86 kg) were analyzed. Patients were divided into subgroups: organ transplantation (OTX, n =28), sepsis or organ failure (SEPSIS, n =16), neurological patients (NEURO, n =9), and preterm infants (PREM, n =26); Bias/MPE for EVVTI was 7.81%/26.16%. In the EVVTI subgroup analysis for OTX, NEURO, and SEPSIS, bias and MPE were within the limits of H0, whereas the PREM subgroup had a bias/MPE of 39.00%/46.27%. Bias/MPE for EVMM was 8.07%/37.26% where the OTX and NEURO subgroups were within the range of H0, but the PREM and SEPSIS subgroups were outside the range. Mechanical ventilation, non-invasive continuous positive airway pressure ventilation, body weight, and secondary abdominal closure were factors that significantly affected comparison of the methods. Conclusions This study shows that EV is comparable with aortic flow-based TTE for pediatric patients.
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Affiliation(s)
- Martin Ernst Blohm
- Department of Pediatrics, Division of Neonatology and Pediatric Intensive Care, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany.
| | - Denise Obrecht
- Department of Pediatrics, Division of Neonatology and Pediatric Intensive Care, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany.
| | - Jana Hartwich
- Department of Pediatrics, Division of Neonatology and Pediatric Intensive Care, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany. .,Current address: Department of Neurology, Elbe Kliniken Stade, Bremervörder Str. 111, Stade, 21682, Germany.
| | - Goetz Christoph Mueller
- Department of Pediatric Cardiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany.
| | - Jan Felix Kersten
- Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany.
| | - Jochen Weil
- Department of Pediatric Cardiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany.
| | - Dominique Singer
- Department of Pediatrics, Division of Neonatology and Pediatric Intensive Care, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany.
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Henry IC, Bernstein DP, Banet MJ. Stroke volume obtained from the brachial artery using transbrachial electrical bioimpedance velocimetry. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2012:142-5. [PMID: 23365852 DOI: 10.1109/embc.2012.6345891] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Stroke volume (SV) is the quantity of blood ejected by the cardiac ventricles per each contraction. When SV is multiplied by heart rate, cardiac output is the result. Cardiac output (CO), in conjunction with hemoglobin concentration and arterial oxygen saturation are the cornerstones of oxygen transport. Measurement of CO is important, especially in sick humans suffering from decompensated heart disease and systemic diseases affecting the contractility or loading conditions of the heart. Although reasonably accurate invasive cardiac output methods are available, their use is restricted to those individuals hospitalized in the intensive care units. Thus, a robust noninvasive alternative is considered desirable. Impedance cardiography (ICG) is one such method, but in patients with severe heart disease and/or excess extravascular lung water, the method is inaccurate. This paper concerns the introduction of a new method, transbrachial electrical bioimpedance velocimetry (TBEV). The technique involves passage of a constant magnitude, high frequency, and low amperage ac from the upper arm to the antecubital fossa. In all other respects, the operational aspects of TBEV are consistent with ICG. There is good evidence suggesting that the TBEV waveform and its derivatives are generated by blood resistivity changes only.
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Bernstein DP, Henry IC, Banet MJ, Dittrich T. Stroke volume obtained by electrical interrogation of the brachial artery: transbrachial electrical bioimpedance velocimetry. Physiol Meas 2012; 33:629-49. [DOI: 10.1088/0967-3334/33/4/629] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Critchley LA, Lee A, Ho AMH. A Critical Review of the Ability of Continuous Cardiac Output Monitors to Measure Trends in Cardiac Output. Anesth Analg 2010; 111:1180-92. [DOI: 10.1213/ane.0b013e3181f08a5b] [Citation(s) in RCA: 380] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Peng ZY, Critchley LAH, Fok BSP. An investigation to show the effect of lung fluid on impedance cardiac output in the anaesthetized dog. Br J Anaesth 2005; 95:458-64. [PMID: 16051651 DOI: 10.1093/bja/aei206] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Accumulation of lung fluid in the critically ill patient is believed to attenuate impedance cardiac output (CO(IC)) measurements. However, this phenomenon has never been shown experimentally. METHODS In eight anaesthetized and ventilated dogs (weight 15-22 kg) a high-precision flow probe was placed on the ascending aorta via a left thoracotomy incision and the direct cardiac output (CO(FP)) was measured. Simultaneous CO(IC) measurements were made using a RheoCardioMonitor (ACMA, Singapore). Lung oedema was induced by intravenous oleic acid 0.1 mg kg(-1). Lung fluid was assessed by the decrease in basal thoracic impedance (Z(b)). Percentage errors between the two methods (CO(IC)-CO(FP)) were calculated and compared as Z(b) decreased at 1 Omega intervals. RESULTS During the experiment mean Z(b) decreased from 35.9 (sd 5.2) to 27.8 (6.5) Omega (P=0.0037). This occurred over a period of 225 (range 112-338) min and Z(b) decreased by 1 Omega every 51 (22-68) min. The presence of excessive lung fluid was confirmed at post-mortem. Before lung oedema was induced, CO(IC) was 1.5 (0.6) litre min(-1) and the corresponding value of CO(FP) was 1.5 (0.7) litre min(-1) (data from eight dogs). As Z(b) decreased, and lung fluid accumulated, the error between CO(IC) and CO(FP) widened (P<0.0001, anova for repeated measures). Eventually, CO(IC) decreased to 0.7 (0.3) litre min(-1) and the corresponding value of CO(FP) was 1.2 (0.3) litre min(-1) (DeltaZ(b)=5 Omega, data from six dogs). Mean arterial pressure, central venous pressure and systemic vascular resistance were kept constant. CONCLUSION The presence of lung fluid attenuates CO(IC) measurements with respect to CO(FP).
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Affiliation(s)
- Z-Y Peng
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Shatin
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Abstract
The study's goal was to determine if cardiac output (CO), obtained by impedance cardiography (ICG), would be improved by a new equation N, implementing a square root transformation for dZ/dtmax/Z0, and a variable magnitude, mass-based volume conductor Vc. Pulmonary artery catheterisation was performed on 106 cardiac surgery patients pre-operatively. Post-operatively, thermodilution cardiac output (TDCO) was simultaneously compared with ICG CO. dZ/dtmax/Z0 and Z0 were obtained from a proprietary bioimpedance device. The impedance variables, in addition to left ventricular ejection time TLVE and patient height and weight, were input using four stroke volume (SV) equations: Kubicek (K), Sramek (S), Sramek-Bernstein (SB), and a new equation N. CO was calculated as SV x heart rate. Data are presented as mean +/- SD. One way repeated measures of ANOVA followed by the Tukey test were used for inter-group comparisons. Bland-Altman methods were used to assess bias, precision and limits of agreement. P< 0.05 was considered statistically significant. CO implementing N (6.06 +/- 1.48 l min(-1)) was not different from TDCO (5.97 +/- 1.41 l min(-1)). By contrast, CO calculated using K (3.70 +/- 1.53 l min(-1)), S (4.16 +/- 1.83 l min(-1)) and SB (4.37 +/- 1.82 l min(-1)) was significantly less than TDCO. Bland-Altman analysis showed poor agreement between TDCO and K, S and SB, but not between TDCO and N. Compared with TDCO, equation N, using a square-root transformation for dZ/dtmax/Z0, and a mass-based Vc, was superior to existing transthoracic impedance techniques for SV and CO determination.
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Affiliation(s)
- D P Bernstein
- Department of Anesthesiology, Palomar Medical Center, Escondido, CA, USA.
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