Continuous stroke volume and cardiac output from intra-ventricular dimensions obtained with impedance catheter

Baan, Jan; Jong, T. T A.; Kerkhof, P. L. M.; Moene, Rudolf J.; Dijk, Arjan D. van; Velde, Enno T. van der; Koops, J.

doi:10.1093/cvr/15.6.328

Cited by 277 publications

(139 citation statements)

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“…This catheter is connected to electronics (Stichting Leycom Sigma-5), which applies a 20-kHz, 0.07-mA RMS current between electrodes 1 and 8, measures conductances between electrode pairs 2-3, 3-4, 4-5, 5-6, and 6-7, and then sums them to obtain the total time-varying conductance, G(t). Absolute LV volume, V(t), is computed as V(t) = (l/a)(L2pG(t) -aVc) (1) where a is a unitless constant, L is interelectrode distance, p is blood resistivity, and aVc is volume correction due to parallel conductance, Gp, outside the LV blood pool (aVc=L2p Gp).…”

Section: Conductance Cathetermentioning

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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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: Conductance Cathetermentioning

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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“…All recordings of pressure and volume data were obtained at end expiration. LV volumes and pressures at end diastole (EDV, EDP) and end systole (ESV, ESP) were obtained from the conductance catheter (2). The time constant of LV relaxation () was derived (4,23).…”

mentioning

confidence: 99%

Impact of myocardial structure and function postinfarction on diastolic strain measurements: implications for assessment of myocardial viability

Park

Nagueh

Khoury

et al. 2006

American Journal of Physiology-Heart and Circulatory Physiology

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. Impact of myocardial structure and function postinfarction on diastolic strain measurements: implications for assessment of myocardial viability. Am J Physiol Heart Circ Physiol 290: H724 -H731, 2006. First published September 23, 2005 doi:10.1152/ajpheart.00714.2005.-We sought to assess the role of regional diastolic function by Doppler echocardiography in predicting myocardial viability. Sixteen dogs underwent left anterior descending coronary artery (n ϭ 8) or circumflex (n ϭ 8) occlusion. All animals were imaged at baseline and 1-8 wk postinfarction (post-MI). In 10 dogs, invasive hemodynamic monitoring with a conductance catheter placed in the left ventricle (LV) was performed at the above time points. Dobutamine was infused at 1-8 wk post-MI to determine LV contractile reserve. Histomorphological analysis was performed to determine the presence of viable myocardium and changes in interstitial matrix. Post-MI, diastolic strain rate measurements (in radial and longitudinal planes) decreased significantly in the distribution of the diseased artery (P Ͻ 0.01) and on multiple regression analysis were determined by time constant of LV relaxation, end-diastolic pressure, regional stiffness, and the ratio of cellular infiltration to collagen deposition in the interstitial matrix. Among several indexes, diastolic strain rate during dobutamine infusion readily identified segments with Ͼ20% transmural infarction and related best to the extent of interstitial fibrosis (r ϭ Ϫ0.86, P Ͻ 0.01). In an animal model of healing canine infarcts, diastolic strain rate by Doppler echocardiography appears to be a promising novel index of myocardial viability. diastole; infarction; coronary THE PROGNOSIS OF PATIENTS with coronary artery disease is largely dependent on the presence and extent of myocardial viability (14). Accordingly, the accurate assessment of viable myocardium is needed for proper patient management. Echocardiographic techniques, in particular dobutamine echocardiography (14), have emerged as important diagnostic modalities that can identify residual viable myocardium in patients with coronary artery disease. There is, however, a paucity of data on the utility of assessment of regional diastolic function in these patients. This approach is important given the recent reports on diastolic function assessment during stress echocardiography (1,12,20).Depending on the extent of ischemia, regional expansion may be delayed at a time when systolic function is normal (1, 21). Alternatively, it is possible for regional stiffness to be relatively unchanged despite the presence of systolic dysfunction as in myocardial stunning (16). Therefore, parameters of diastolic function can provide incremental information in identifying the extent of myocardial necrosis compared with indexes of systolic function in patients with coronary artery disease. In this regard, it is possible to assess regional function objectively using strain Doppler imaging (9, 13, 19). We therefore underwent this experimental study in dogs to test the hy...

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“…A conductance catheter was used for the simultaneous recording of LV pressure and the volume signal (16). The catheter consists of pressure-conductivity transducers.…”

Section: Conductance Catheter Methodsmentioning

confidence: 99%

Measurement of Myocardial Contractility in the Ischemic Heart – A Disease Immanent Uncertainty

Broscheit¹

2012

Novel Strategies in Ischemic Heart Disease

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Continuous stroke volume and cardiac output from intra-ventricular dimensions obtained with impedance catheter

Cited by 277 publications

References 0 publications

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

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

Impact of myocardial structure and function postinfarction on diastolic strain measurements: implications for assessment of myocardial viability

Measurement of Myocardial Contractility in the Ischemic Heart – A Disease Immanent Uncertainty

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