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Article: Right ventricular volume measurement by conductance catheter

TitleRight ventricular volume measurement by conductance catheter
Authors
Issue Date2003
Citation
American Journal of Physiology - Heart and Circulatory Physiology, 2003, v. 285 n. 4 54-4, p. H1774-H1785 How to Cite?
AbstractContinuous ventricular volume measurement by the conductance method assumes a homogeneous electrical field dispersed throughout and contained within the ventricle. Because of dense trabeculation and complex geometry, right ventricular (RV) volume description by this method may be seriously compromised. This study sought to determine the accuracy and limitations of RV volume measurement by conductance, with magnetic resonance (MR) imaging (MRI) used as a reference, in the porcine RV. Anesthetized pigs (n = 5, 45-55 kg) were placed in a 1.5-T magnet, and ECG-gated transverse MR images (5-mm slices) were acquired during the complete cardiac cycle. RV cavity volumes were subsequently determined by Simpson's technique. Animals were then instrumented with an RV conductance catheter and an ultrasonic pulmonary artery flow probe. Conductance catheter signals were recorded using single- and dual-field (SF and DF) excitation, and the saline-dilution technique was used to correct volumes for parallel conductance. The gain factor (α) was calculated as the ratio of conductance- to MRI-derived stroke volume (α sv). Variation of α during the cardiac cycle was computed by comparing RV conductance volumes with 1) MRI volumes at isochronal time points within the cardiac cycle [α(t)] and 2) the pulmonary flow integral during ejection. After calibration, the conductance-MRI volume relation was modeled lin-early with good correlation [r = 0.96 (SF) and r = 0.94 (DF)], close to the line of identity. Individual conductance-MRI plots displayed a slight curvilinear relation that was concave toward the MRI axis. Consistent with this finding, α(t) varied significantly during the cardiac cycle (0.49 and 0.39 by SF for end systole and end diastole, respectively, P = 0.011). DF excitation resulted in improved volume measurement [α sv = 0.41 (SF) and 0.96 (DF)], with less variation in α(t) (1.0 and 0.92 by DF for end systole and end diastole, respectively, P = 0.66). These results indicate that, with calibration, the conductance method can measure absolute RV volume under steady-state conditions. However, the curvilinearity and α(t) variation would indicate the potential for nonlinearity when RV volumes are varied over a wider range.
Persistent Identifierhttp://hdl.handle.net/10722/192660
ISSN
2015 Impact Factor: 3.324
2015 SCImago Journal Rankings: 1.823
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorDanton, MHDen_US
dc.contributor.authorGreil, GFen_US
dc.contributor.authorByrne, JGen_US
dc.contributor.authorHsin, Men_US
dc.contributor.authorCohn, Len_US
dc.contributor.authorMaier, SEen_US
dc.date.accessioned2013-11-20T04:54:56Z-
dc.date.available2013-11-20T04:54:56Z-
dc.date.issued2003en_US
dc.identifier.citationAmerican Journal of Physiology - Heart and Circulatory Physiology, 2003, v. 285 n. 4 54-4, p. H1774-H1785en_US
dc.identifier.issn0363-6135en_US
dc.identifier.urihttp://hdl.handle.net/10722/192660-
dc.description.abstractContinuous ventricular volume measurement by the conductance method assumes a homogeneous electrical field dispersed throughout and contained within the ventricle. Because of dense trabeculation and complex geometry, right ventricular (RV) volume description by this method may be seriously compromised. This study sought to determine the accuracy and limitations of RV volume measurement by conductance, with magnetic resonance (MR) imaging (MRI) used as a reference, in the porcine RV. Anesthetized pigs (n = 5, 45-55 kg) were placed in a 1.5-T magnet, and ECG-gated transverse MR images (5-mm slices) were acquired during the complete cardiac cycle. RV cavity volumes were subsequently determined by Simpson's technique. Animals were then instrumented with an RV conductance catheter and an ultrasonic pulmonary artery flow probe. Conductance catheter signals were recorded using single- and dual-field (SF and DF) excitation, and the saline-dilution technique was used to correct volumes for parallel conductance. The gain factor (α) was calculated as the ratio of conductance- to MRI-derived stroke volume (α sv). Variation of α during the cardiac cycle was computed by comparing RV conductance volumes with 1) MRI volumes at isochronal time points within the cardiac cycle [α(t)] and 2) the pulmonary flow integral during ejection. After calibration, the conductance-MRI volume relation was modeled lin-early with good correlation [r = 0.96 (SF) and r = 0.94 (DF)], close to the line of identity. Individual conductance-MRI plots displayed a slight curvilinear relation that was concave toward the MRI axis. Consistent with this finding, α(t) varied significantly during the cardiac cycle (0.49 and 0.39 by SF for end systole and end diastole, respectively, P = 0.011). DF excitation resulted in improved volume measurement [α sv = 0.41 (SF) and 0.96 (DF)], with less variation in α(t) (1.0 and 0.92 by DF for end systole and end diastole, respectively, P = 0.66). These results indicate that, with calibration, the conductance method can measure absolute RV volume under steady-state conditions. However, the curvilinearity and α(t) variation would indicate the potential for nonlinearity when RV volumes are varied over a wider range.en_US
dc.languageengen_US
dc.relation.ispartofAmerican Journal of Physiology - Heart and Circulatory Physiologyen_US
dc.titleRight ventricular volume measurement by conductance catheteren_US
dc.typeArticleen_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1152/ajpheart.00048.2003-
dc.identifier.pmid12763744-
dc.identifier.scopuseid_2-s2.0-0141788691en_US
dc.identifier.volume285en_US
dc.identifier.issue4 54-4en_US
dc.identifier.spageH1774en_US
dc.identifier.epageH1785en_US
dc.identifier.isiWOS:000185249900049-

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