The hypertonic saline method accurately determined parallel conductance compared with angiographically derived measurements (R2 = 0.92; bias +/- 2SD = 0.002 +/- 0.112 Omega(-1)).
Does the hypertonic saline method accurately determine parallel conductance compared to biplane angiography in a dual-field conductance catheter model?
The hypertonic saline method accurately determines parallel conductance for dual-field conductance catheters across various hemodynamic conditions, validating its use against biplane angiography.
Effect estimate: R2 = 0.92
Conversion of conductance catheter data to absolute ventricular volumes requires assessment of parallel conductance (G(P)). We determined the accuracy of GP obtained by the hypertonic saline method (G(P)saline) compared with angiographically derived GP (G(P)Angio) and quantified the variabilities of GP for the dual-field conductance catheter method in nine anesthetized sheep studied at baseline, treated with dobutamine, and subjected to volume loading and beta-blockade. G(P)saline and G(P)Angio showed an excellent linear correlation (G(P)saline = 1.002 x G(P)Angio + 0.001 Omega(-1), R2 = 0.92), and Bland-Altman analysis yielded a nonsignificant bias and narrow limits of agreement (bias +/- 2SD = 0.002 +/- 0.112 Omega(-1)). Within-animal variability of GP was very similar with both methods and was due to changes in blood conductivity rather than geometrical changes. Variability between animals was significant (26.3% of mean for G(P)saline and 25.7% for G(P)Angio) and thus warrants individual assessment. Variations during the cardiac cycle were not significantly different from zero. With biplane angiography used as gold standard, the hypertonic saline method accurately determines GP for the dual-field conductance catheter over a wide range of hemodynamic conditions.
Steendijk et al. (Wed,) conducted a other in Assessment of parallel conductance (n=9). Hypertonic saline method vs. Angiographically derived parallel conductance was evaluated on Accuracy of parallel conductance obtained by the hypertonic saline method compared with angiographically derived parallel conductance (R2 = 0.92). The hypertonic saline method accurately determined parallel conductance compared with angiographically derived measurements (R2 = 0.92; bias +/- 2SD = 0.002 +/- 0.112 Omega(-1)).