Estimates of cardiac output from forward part of indicator dilution curves

1961 ◽  
Vol 16 (5) ◽  
pp. 891-895 ◽  
Author(s):  
Geoffrey D. Thorburn
Keyword(s):  
Cardiac Output ◽  
Injection Site ◽  
Path Length ◽  
Indicator Dilution ◽  
New Method ◽  
Flow Volume ◽  
Initial Part ◽  
Dye Dilution ◽  
Forward Part ◽  
Dilution Curves

A study was made of 135 dye-dilution curves, 77 of which were obtained from dogs and 58 from man. It was previously shown that the degree of asymmetry of indicator dilution curves varies with changes in flow, volume, and path length, and this has been found to influence the estimates of cardiac output made from the initial part of the curves by the forward triangle and Dow methods, and by a new method described in this paper. This variation may be minimized by the calculation of separate constants for each injection site and by keeping the variation in flow and volume as small as possible. Errors are likely to arise when these methods are used outside the range of the normal data. It has been found that this variation in asymmetry is mainly responsible for the scatter in the estimates of cardiac output using these methods. The agreement between the forward triangle and the Dow methods was found to be very close and the reason for this is discussed. Submitted on February 13, 1961

A new method for calibrating indicator dilution curves

1975 ◽  
Vol 38 (3) ◽  
pp. 550-553
Author(s):  
J. Boyle ◽  
P. Diamond
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Electromagnetic Flowmeter ◽  
Usual Method ◽  
Indicator Dilution ◽  
New Method ◽  
Reasonable Accuracy ◽  
Dilution Curves

A technique is proposed and experiments carried out to validate an in vivo method of calibrating ascorbate dilution curves. Cardiac output measured by the proposed method (COi) was compared to cardiac output measured by electromagnetic flowmeter (COe). COe averaged 1,281 mg/min and COi averaged 1,284 ml/min (P greater than 0.90). Correlation between the two methods was 0.92. It is concluded that the proposed method measures CO with reasonable accuracy and provides a number of advantages over the usual method of measuring blood flow by means of indicators.

Cardiac output: Rapid estimation from indicator dilution curves using a new Nomogram

1970 ◽  
Vol 48 (2) ◽  
pp. 147-149 ◽  
Author(s):  
P. M. Olley ◽  
B. S. L. Kidd ◽  
S. Zelin
Keyword(s):  
Cardiac Output ◽  
Correlation Coefficient ◽  
Exponential Decay ◽  
Indicator Dilution ◽  
Dilution Curve ◽  
Rapid Estimation ◽  
Dye Dilution ◽  
Dilution Curves

Estimation of the cardiac output from dye dilution curves using Hamilton's method is time consuming when many curves require analysis. We have designed a Nomogram based on the treatment of the dilution curve as a series of three parabolas followed by an exponential decay. The results obtained from this Nomogram have been compared with those obtained by Hamilton's method and given a correlation coefficient of 0.998.

Physiological parameters of indicator dilution curves

1977 ◽  
Vol 233 (3) ◽  
pp. H350-H355
Author(s):  
L. D. Homer ◽  
A. Small
Keyword(s):  
Cardiac Output ◽  
Satisfactory Agreement ◽  
Single Injection ◽  
Time Lag ◽  
Volume Of Distribution ◽  
Physiological Parameters ◽  
Indicator Dilution ◽  
Diethylenetriaminepentaacetic Acid ◽  
Alternative Techniques ◽  
Dilution Curves

A model incorporating the effects of recirculation time lag, cardiac output, clearance, volume of distribution, and the variance of the distribution of recirculation times is applied to the analysis of indicator dilution curves. Experiments on dogs with use of radioactively labeled diethylenetriaminepentaacetic acid were done to evaluate the model. This five-parameter model can be fitted to data obtained during the period from less than 1 min to 3 h after a single injection of indicator. Estimates of cardiac output and clearance are in satisfactory agreement with estimates obtained by alternative techniques. Estimates of the time lag and volume of distribution are of physiologically plausible magnitude. The variance of the distribution of recirculation times is a new parameter, of which the possible usefulness to physiologists is discussed.

A small, lightweight precordial counter for determination of cardiac output

1965 ◽  
Vol 20 (6) ◽  
pp. 1365-1366 ◽  
Author(s):  
Ralph J. Gorten
Keyword(s):  
Cardiac Output ◽  
Scintillation Detector ◽  
Treadmill Exercise ◽  
Bicycle Ergometer ◽  
Indicator Dilution ◽  
Energy Gamma ◽  
Lead Shielding ◽  
Thin Crystal ◽  
Dilution Curves

A compact, lightweight scintillation detector which can be firmly attached to the anterior chest was fabricated in order to better adapt the isotope-precordial counting technic for measurements of cardiac output during exercise. In this manner useful indicator-dilution curves can be obtained without arterial puncture at light-to-heavy levels of bicycle ergometer or treadmill exercise. The use of a thin crystal and the omission of lead shielding and collimation of the detector is possible with a soft-energy gamma-emitting indicator of blood flow such as iodinated (I125) albumin. cardiac output during exercise; lightweight precordial scintillation detector; iodione 125; isotope-precordial counting technic Submitted on May 28, 1965

A new method of analysing indicator dilution curves

1995 ◽  
Vol 30 (6) ◽  
pp. 930-938 ◽  
Author(s):  
R.A.F. Linton ◽  
N.W.F. Linton ◽  
D.M. Band
Keyword(s):  
Indicator Dilution ◽  
New Method ◽  
Dilution Curves

Performance of a new on-line computer for indicator-dilution curves

1964 ◽  
Vol 19 (5) ◽  
pp. 1024-1027 ◽  
Author(s):  
Hans U. Wessel ◽  
Charles F. Hepner ◽  
Gordon W. James ◽  
Paul Kezdi
Keyword(s):  
Cardiac Output ◽  
Goodness Of Fit ◽  
Analog Computer ◽  
Indicator Dilution ◽  
Stable Operation ◽  
Flow Rates ◽  
On Line ◽  
The Mean ◽  
Graphic Methods ◽  
Dilution Curves

An analog computer was designed for on-line computation of the area under indicator-dilution curves. From a model circulation and from two dogs, 165 tricarbocyanine green dilution curves were recorded with a cuvette densitometer, together with the computed area and signals indicating 60% and 30% of the peak deflection on the down slope of the curve. An IBM 709 digital computer was programmed to compare automatically and conventionally computed flow rates, to analyze sources of error in the computer, and to determine the goodness of fit of the extrapolated exponentials. The results indicated stable operation of the computer. The mean difference between the computer and graphic integration was minus 1.0% ± 2.4% for 78 flow estimates in the model, and 1.9% ± 2.5% for 30 cardiac output in the dogs. Data suggest that the computer does not introduce a significant error provided the dilution curves are also suitable for established graphic methods of integration. special purpose analog computer; instrumentation; cardiac output Submitted on December 6, 1963

scholarly journals Cardiac Output and Central Volume as Determined by Dye Dilution Curves

Circulation ◽  
1955 ◽  
Vol 11 (3) ◽  
pp. 447-455 ◽  
Author(s):  
ALBERT A. KATTUS ◽  
ARTHUR U. RIVIN ◽  
AARON COHEN ◽  
GILBERT S. SOFIO
Keyword(s):  
Cardiac Output ◽  
Dye Dilution ◽  
Central Volume ◽  
Dilution Curves
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