scholarly journals Ventricular Nonmixing as a Source of Error in the Estimation of Ventricular Volume by the Indicator-Dilution Technic

1960 ◽  
Vol 8 (5) ◽  
pp. 989-998 ◽  
Author(s):  
H. J. C. SWAN ◽  
WALTER BECK
Keyword(s):  
Ventricular Volume ◽  
Indicator Dilution ◽  
Source Of Error

Cardiac output by rebreathing in patients with cardiopulmonary diseases

1987 ◽  
Vol 63 (1) ◽  
pp. 201-210 ◽  
Author(s):  
M. C. Kallay ◽  
R. W. Hyde ◽  
R. J. Smith ◽  
R. L. Rothbard ◽  
B. F. Schreiner
Keyword(s):  
Cardiac Output ◽  
Pulmonary Blood Flow ◽  
Obstructive Lung Disease ◽  
Volume Ratio ◽  
Indicator Dilution ◽  
Pulmonary Diseases ◽  
Normal Lung ◽  
Uneven Ventilation ◽  
Gas Volume ◽  
Source Of Error

Noninvasive estimates of cardiac output by rebreathing soluble gases (Qc) can be unreliable in patients with cardiopulmonary diseases because of uneven distribution of ventilation to lung gas volume and pulmonary blood flow. To evaluate this source of error, we compared rebreathing Qc with invasive measurements of cardiac output performed by indicator-dilution methods (COID) in 39 patients with cardiac or pulmonary diseases. In 16 patients with normal lung volumes and 1-s forced expiratory volumes (FEV1), Qc measured with acetylene [Qc(C2H2)] overestimated COID insignificantly by 2 +/- 9% (SD). In subjects with mild to moderate obstructive lung disease, Qc(C2H2) slightly overestimated COID by 6 +/- 15% (P = 0.11). In patients with restrictive disease or combined obstructive and restrictive disease, Qc(C2H2) underestimated COID significantly by 9 +/- 14% (P less than 0.04). The magnitude of the discrepancy between Qc and COID correlated with size of the volume rebreathed and an index of uneven ventilation calculated from helium mixing during rebreathing that determined a dead space to inspired volume ratio (VRD/VI). Rebreathing volumes less than 40% of the predicted FEV or VRD/VI of 0.4 or greater identified all subjects with a discrepancy between Qc(C2H2) and COID of 20% or greater.

Thermodilution studies of ventricular volume changes due to isoproterenol and bleeding

1963 ◽  
Vol 18 (1) ◽  
pp. 129-133 ◽  
Author(s):  
J. David Bristow ◽  
Richard E. Ferguson ◽  
Fredric Mintz ◽  
Elliot Rapaport
Keyword(s):  
Ventricular Volume ◽  
Left Ventricular ◽  
Indicator Dilution ◽  
Dilution Method ◽  
Volume Changes ◽  
Thermodilution Technique ◽  
End Diastolic Volume ◽  
Before And After ◽  
Anesthetized Dogs ◽  
Ventricular Dimensions

The effects of intravenous isoproterenol on left ventricular stroke and on end-systolic and end-diastolic volumes were studied in anesthetized dogs before and after bleeding. Volumes were measured by a thermodilution technique. In this indicator-dilution method a small amount of cooled blood is rapidly injected into the ventricle, and the washout of cold from the ventricle is sensed by a thermistor catheter at the root of the aorta. Control values showed that approximately two-thirds of the end-diastolic volume remained in the ventricle at the end of systole. Bleeding decreased all three volumes. Isoproterenol consistently increased ventricular emptying, as shown by the fall in the proportion of the end-diastolic volume which remained at end systole. This effect did not depend on an increase or decrease in the end-diastolic volume itself. End-systolic force-circumference relationships were derived from a consideration of idealized ventricular dimensions. A linear relationship between these calculated values was not altered by isoproterenol. Submitted on July 5, 1962

Measurement of left ventricular volume by thermodilution: an appraisal of technical errors

1964 ◽  
Vol 19 (6) ◽  
pp. 1164-1174 ◽  
Author(s):  
Ellis L. Rolett ◽  
Herbert Sherman ◽  
Richard Gorlin
Keyword(s):  
Time Constant ◽  
Left Ventricular Volume ◽  
Ventricular Volume ◽  
Left Ventricular ◽  
Indicator Dilution ◽  
Valvular Regurgitation ◽  
True Rate ◽  
End Diastolic Volume ◽  
Technical Errors

An analysis of the technical errors inherent in the determination of left ventricular volume by indicator-dilution methods, particularly thermodilution, is presented. Inaccuracies in the measurement of the true rate of indicator washout from the ventricle are related to valvular regurgitation, heat transfer between ventricular wall and chamber, and a long sensor time constant; variations occur due to heterogeneous indicator mixing in the chamber and at the transducer. It is shown that, whatever the reason for error, it multiplies as the fraction of ventricular emptying becomes smaller. The error is reduced through the use of a sensor with an appropriately short time constant and through the acquisition of multiple dilution curves and stroke volume measurements. An estimate of the relative error in the computed left ventricular volume is possible and only under optimal circumstances is close to that found in the determination of cardiac output. The remaining variation in computed volume is primarily an indication of variable indicator mixing. The conditions required for reliability are extensive and place restrictions on the general usefulness of the method. indicator-dilution technic; end-diastolic volume; residual volume; thermistor Submitted on October 29, 1963

Normal cerebral ventricular volume growth in childhood

2020 ◽  
Vol 26 (5) ◽  
pp. 517-524
Author(s):  
Noah S. Cutler ◽  
Sudharsan Srinivasan ◽  
Bryan L. Aaron ◽  
Sharath Kumar Anand ◽  
Michael S. Kang ◽  
...  
Keyword(s):  
Brain Mri ◽  
Volume Growth ◽  
Ventricular Volume ◽  
Growth Patterns ◽  
Diagnostic Process ◽  
Growth Charts ◽  
Normal Brain ◽  
Mr Images ◽  
Ventricular Volumes ◽  
Brain Mr Images

OBJECTIVENormal percentile growth charts for head circumference, length, and weight are well-established tools for clinicians to detect abnormal growth patterns. Currently, no standard exists for evaluating normal size or growth of cerebral ventricular volume. The current standard practice relies on clinical experience for a subjective assessment of cerebral ventricular size to determine whether a patient is outside the normal volume range. An improved definition of normal ventricular volumes would facilitate a more data-driven diagnostic process. The authors sought to develop a growth curve of cerebral ventricular volumes using a large number of normal pediatric brain MR images.METHODSThe authors performed a retrospective analysis of patients aged 0 to 18 years, who were evaluated at their institution between 2009 and 2016 with brain MRI performed for headaches, convulsions, or head injury. Patients were excluded for diagnoses of hydrocephalus, congenital brain malformations, intracranial hemorrhage, meningitis, or intracranial mass lesions established at any time during a 3- to 10-year follow-up. The volume of the cerebral ventricles for each T2-weighted MRI sequence was calculated with a custom semiautomated segmentation program written in MATLAB. Normal percentile curves were calculated using the lambda-mu-sigma smoothing method.RESULTSVentricular volume was calculated for 687 normal brain MR images obtained in 617 different patients. A chart with standardized growth curves was developed from this set of normal ventricular volumes representing the 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles. The charted data were binned by age at scan date by 3-month intervals for ages 0–1 year, 6-month intervals for ages 1–3 years, and 12-month intervals for ages 3–18 years. Additional percentile values were calculated for boys only and girls only.CONCLUSIONSThe authors developed centile estimation growth charts of normal 3D ventricular volumes measured on brain MRI for pediatric patients. These charts may serve as a quantitative clinical reference to help discern normal variance from pathologic ventriculomegaly.

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