The Accuracy and Reliability of Cardiac Output Assessment by Measuring Descending Aortic Blood Flow in Patients Undergoing Cardiac Surgery

Abstract Background To investigate the accuracy and reliability of cardiac output (CO) assessment by transesophageal echocardiographic (TEE) measuring descending aortic blood flow (DABF) in patients undergoing cardiac surgery under cardiopulmonary bypass (CPB). And the influence of DABF/CO on the accuracy and reliability of CO assessment were also analyzed. Methods Paired CO measured by both thermodilution (TCO) and Doppler method (DCO) were obtained before incision, immediately after CPB, 15 minutes after CPB, 30 minutes after CPB, 45 minutes after CPB, and at the end of surgery. The DCO was converted from TEE measured DABF using theoretical proportion (70%) of DABF/CO. Regression analysis, Bland-Altman graph, and Polar plot were used to analyze the correlation and agreement between the CO measurements by the two methods. Parameters were compared by one-way ANOVA among different time points. Results A total of 132 pairs of CO measurements were obtained from 22 patients. The average proportion of DABF/TCO ranged from 54% before CPB to 63% after CBP. A good correlation between DCO and TCO (r = 0.81) was found. The Bland-Altman analysis showed a large positive bias between the TCO and DCO. The Polar plot also showed a poor concordance between changes of DCO and TCO. The proportion of DABF/TCO had a mild negative correlation with systemic vascular resistance index (SVRI) but not with cardiac output index (CI). Conclusions The CO, converted from TEE measured DABF, was underestimated in patients undergoing cardiac surgery. The varied proportion between DABF and CO mainly influenced the accuracy and reliability of CO assessment. Trial registration: Chinese Clinical Trials Register Identifier: ChiCTR-OCS-12002789 (retrospective registered). Date: 2012.12.21

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A simple module for on-line computation of stroke volume and cardiac output

Journal of Applied Physiology ◽

10.1152/jappl.1975.38.5.927 ◽

1975 ◽

Vol 38 (5) ◽

pp. 927-929 ◽

Cited By ~ 1

Author(s):

G. Pinardi ◽

A. Sainz ◽

E. Santiago

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Data Analysis ◽

Stroke Volume ◽

Simple Module ◽

Cardiovascular Responses ◽

Aortic Blood Flow ◽

Aortic Blood ◽

On Line ◽

Aortic Blood Flow Velocity

An easily constructed, low-priced, simple, and reliable module to obtain stroke volume and cardiac output by analog integration of aortic blood flow velocity signals is described. Rapid data analysis of physiologic and pharmacologic cardiovascular responses in dogs is greatly facilitated by on line computation of these parameters.

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A Novel Idea to Improve Cardiac Output of Mechanical Circulatory Support Devices by Optimizing Kinetic Energy Transfer Available in Forward Moving Aortic Blood Flow

Cardiovascular Engineering and Technology ◽

10.1007/s13239-017-0305-2 ◽

2017 ◽

Vol 8 (2) ◽

pp. 131-144

Author(s):

Muhammad B. Qureshi ◽

Jacob Glower ◽

Daniel L. Ewert ◽

Steven C. Koenig

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Energy Transfer ◽

Mechanical Circulatory Support ◽

Circulatory Support ◽

Aortic Blood Flow ◽

Aortic Blood ◽

Mechanical Circulatory Support Devices ◽

Support Devices ◽

Kinetic Energy Transfer

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Instantaneous Aortic Blood Flow and Cardiac Output

Acta Physiologica Scandinavica ◽

10.1111/j.1748-1716.1962.tb02403.x ◽

1962 ◽

Vol 54 ◽

pp. 37-50

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Aortic Blood Flow ◽

Aortic Blood

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Estimation of changes in instantaneous aortic blood flow by the analysis of arterial blood pressure

Journal of Applied Physiology ◽

10.1152/japplphysiol.01565.2011 ◽

2012 ◽

Vol 112 (11) ◽

pp. 1832-1838 ◽

Cited By ~ 4

Author(s):

Tatsuya Arai ◽

Kichang Lee ◽

Robert P. Marini ◽

Richard J. Cohen

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Cardiac Output ◽

Stroke Volume ◽

Arterial Blood Pressure ◽

Aortic Blood Flow ◽

Windkessel Model ◽

Arx Model ◽

Arterial Blood ◽

Aortic Blood

The purpose of this study was to introduce and validate a new algorithm to estimate instantaneous aortic blood flow (ABF) by mathematical analysis of arterial blood pressure (ABP) waveforms. The algorithm is based on an autoregressive with exogenous input (ARX) model. We applied this algorithm to diastolic ABP waveforms to estimate the autoregressive model coefficients by requiring the estimated diastolic flow to be zero. The algorithm incorporating the coefficients was then applied to the entire ABP signal to estimate ABF. The algorithm was applied to six Yorkshire swine data sets over a wide range of physiological conditions for validation. Quantitative measures of waveform shape (standard deviation, skewness, and kurtosis), as well as stroke volume and cardiac output from the estimated ABF, were computed. Values of these measures were compared with those obtained from ABF waveforms recorded using a Transonic aortic flow probe placed around the aortic root. The estimation errors were compared with those obtained using a windkessel model. The ARX model algorithm achieved significantly lower errors in the waveform measures, stroke volume, and cardiac output than those obtained using the windkessel model ( P < 0.05).

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