Angiographic validation of eigenvolume to measure left ventricular size.

Chagas, A. C. P.; Glantz, Stanton A.

doi:10.1161/01.res.62.6.1237

Cited by 4 publications

(3 citation statements)

References 16 publications

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“…Seven data channels were recorded: 1) LV pressure, 2) RV pressure, 3) electrode-pair 4-5 segmental volume, 4) electrode-pair 5-6 segmental volume, 5) electrode-pair 6-7 segmental volume, 6 Using this coding scheme, the bi represents the deviation from the overall mean value for dog i (i=901, ... , 906). The deviation of dog 907 from the overall average is b07=-Tbi, i=901, .…”

Section: Data Acquisitionmentioning

confidence: 99%

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Left ventricular volume measurement by conductance catheter in intact dogs. Parallel conductance volume depends on left ventricular size.

1989

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The conductance catheter is a promising new instrument for continuously measuring left ventricular (LV) volume. Absolute LV volume (V[t]) is related to uncorrected conductance volume, B(t), according to the equation: V(t)=(1/a)(B(t)-aVe). The aV, factor represents parallel-conductance volume due to conducting material outside the LV blood pool, and may be estimated by transiently changing blood conductivity using a bolus injection of hypertonic saline.a is the slope in the relation between B(t) and true LV volume. We tested the assumption that aVc and av are constant over a range of hemodynamic conditions. We performed multiple hypertonic saline aV, determinations in seven intact dogs during control conditions and subsequent temporary balloon occlusions of inferior vena cava (IVCO), aorta (AO), and pulmonary artery (PAO). We also compared B(t) with simultaneous biplane angiographic LV volume during similar control and intervention conditions. The saline-derived cvV, was 76±2 ml during control and fell significantly by -7±2 ml during IVCO (p<0.001) but not during AO or PAO. According to multiple linear regression analyses, the strongest predictor of saline-derived aV, was uncorrected end-systolic Bes, with a sensitivity coefficient of 0.60+±0.06 ml/ml (p<0.001). Angiographically derived aVc showed a similar dependence on Bes, with a coefficient of 0.77±0.14 ml/ml (p<0.001).Angiographically determined a also showed significant variation with hemodynamic interventions, largely reflecting an underlying dependence on aV,. The variation in aV, and av with LV size may stem from nonlinearity in the B(t)-V(t) relation. Although the conductance catheter provides a useful measure of relative LV volume, measurement of absolute LV volume over a wide hemodynamic range using constant aVc and a factors is unrealistic. This result calls into question the current use of this technique for the measurement of the absolute end-systolicpressure-volume relation. (Circulation 1989;80:1360-1377

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Section: Data Acquisitionmentioning

confidence: 99%

“…We also tested for systematic variation in a by regressing it against individual hemodynamic variables, using Equation 6. As detailed in Table 5 (9) Figure 9 shows a plot of Equation 9 using average values of a0, a1, bo, and b1 from the angiographic data.…”

Section: Angiographic Studiesmentioning

confidence: 99%

Left ventricular volume measurement by conductance catheter in intact dogs. Parallel conductance volume depends on left ventricular size.

1989

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“…Variability is noted in the studies validating angiocardiography as a technique for volume measurement (18,21,22), and it frequently overestimates true volume (1 8, 2 1-24). More importantly, angiocardiography alters the loading conditions and contractile function of the ventricle (25). Volumes measured using cross-sectional echocardiography have considerable variability (26)(27)(28), often underestimate volume when compared to cineangiography (26,27), and require substantial time for calculation of volume.…”

Section: Discussionmentioning

confidence: 99%

The Conductance Volume Catheter Technique for Measurement of Left Ventricular Volume in Young Piglets

Cassidy

Teitel

1992

Pediatr Res

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ABSTRACT. The conductance catheter has been used extensively in the adult for instantaneous and continuous measurement of left ventricular volumes, but has not been validated for use in the small heart. To determine the accuracy of this technique, we simultaneously measured left ventricular volume by the conductance catheter and biplane cineangiography in nine piglets (2-5 wk of age) over a wide range of volumes experimentally altered by volume infusion, hemorrhage, inferior vena caval occlusion, or administration of phenylephrine, isoproterenol, or propranolol. We performed 110 comparisons and determined parallel conductance of contiguous structures (aV,) for each comparison using the saline technique. End-systole and end-diastole volumes were estimated by angiography using Simpson's rule. Raw and aV,-corrected conductance volumes were compared to simultaneously obtained angiographic volumes by multiple regression analyses, using dummy variable coding for the effects of the interanimal variability and the phase of the cardiac cycle. Raw conductance volumes correlated highly with the cineangiographic volumes ( r = 0.97), and the coefficient of angiographic volumes was near identity (1.11 2 0.04). The phase of the cardiac cycle did not have a significant effect. However, aV,-corrected conductance volumes correlated less well (r = 0.85), probably related to the fact that estimated aV, was found to vary with ventricular volume. Thus, the conductance catheter affords a very accurate technique for measuring instantaneous changes in ventricular volume in the small heart, although correction to absolute volumes using the saline technique for estimation of aV, may induce some inaccuracy. (Pediatr Res 31: 85-90, 1992) Abbreviations aV,, parallel conductance Evaluation of left ventricular systolic and diastolic performance in the pressure-volume plane has been widely investigated, and a variety of indices have been derived that shed light on the intrinsic function of the myocardium during contraction, relaxation and passive filling (1-6). Such studies often require generation of repeated pressure-volume loops during hemodynamic perturbations such as occlusion of the inferior vena cava. The ideal technique would continuously measure volume, preferably instantaneously generating values, so that the loops could be

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