A new approach to determine parallel conductance for left ventricular volume measurements.
OBJECTIVE
To determine absolute ventricular volume with the conductance catheter technique, the electrical conductance of tissues and fluids (parallel conductance) around the ventricle should be determined precisely.


METHODS
A new objective method to estimate parallel conductance based on analysis of the dilution curve of hypertonic saline was investigated. The parallel conductances obtained with the new method (G(a)(p)) were compared to those obtained with the conventional method (G(l)(p)). The study was performed in the left ventricle of 12 patients.


RESULTS
G(a)(p) was not significantly different from G(l)(p). For the G(l)(p) method the average percentage difference between duplicate values, both taken as absolute values, was 15.06% and for the G(a)(p) method it was 4. 01%. Thus the reproducibility of the method is a factor four better than that of the method. This difference appeared to be significant.


CONCLUSIONS
We conclude that a smaller number of injections will be required to obtain the same precision using our method.
Kornet
L
L
Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands. l.kornet@fys.unimaas.nl
Schreuder
J J
JJ
van der Velde
E T
ET
Baan
J
J
Jansen
J R
JR
D006328:Cardiac Catheterization; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D004553:Electric Conductivity; D006339:Heart Rate; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D015203:Reproducibility of Results; D012462:Saline Solution, Hypertonic; D013318:Stroke Volume; D013815:Thermodilution
D012462:Saline Solution, Hypertonic