Ineke Nederend1, Arend D J Ten Harkel2, Nico A Blom3, Gary G Berntson4, Eco J C de Geus5. 1. Vrije Universiteit Amsterdam, Amsterdam Public Health Research Institute, Department of Biological Psychology, Faculty of Behavioral and Movement Sciences, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands; Department of Pediatric Cardiology, LUMC University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands. Electronic address: i.nederend@vu.nl. 2. Department of Pediatric Cardiology, LUMC University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands. Electronic address: A.D.J.ten_Harkel@lumc.nl. 3. Department of Pediatric Cardiology, LUMC University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands. Electronic address: N.A.Blom@lumc.nl. 4. Ohio State University, Department of Psychology, 1835 Neil Avenue, Columbus OH 43210, United States. Electronic address: berntson.2@osu.edu. 5. Vrije Universiteit Amsterdam, Amsterdam Public Health Research Institute, Department of Biological Psychology, Faculty of Behavioral and Movement Sciences, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands. Electronic address: eco.de.geus@vu.nl.
Abstract
INTRODUCTION: Stroke volume (SV) and cardiac output are important measures in the clinical evaluation of cardiac patients and are also frequently used in research applications. This study was aimed to improve SV scoring derived from spot-electrode based impedance cardiography (ICG) in a pediatric population of healthy volunteers and patients with a corrected congenital heart defect. METHODS: 128 healthy volunteers and 66 patients participated. First, scoring methods for ambiguous ICG signals were optimized to improve agreement of B- and X-points with aortic valve opening/closure in simultaneously recorded transthoracic echocardiography (TTE). Building on the improved scoring of B- and X-points, the Kubicek equation for SV estimation was optimized by testing the agreement with the simultaneously recorded SV by TTE. Both steps were initially done in a subset of the sample of healthy children and then validated in the remaining subset of healthy children and in a sample of patients. RESULTS: SV assessment by ICG in healthy children strongly improved (intra class correlation increased from 0.26 to 0.72) after replacing baseline thorax impedance (Z0) in the Kubicek equation by an equation (7.337-6.208∗dZ/dtmax), where dZ/dtmax is the amplitude of the ICG signal at the C-point. Reliable SV assessment remained more difficult in patients compared to healthy controls. CONCLUSIONS: After proper adjustment of the Kubicek equation, SV assessed by the use of spot-electrode based ICG is comparable to that obtained from TTE. This approach is highly feasible in a pediatric population and can be used in an ambulatory setting.
INTRODUCTION:Stroke volume (SV) and cardiac output are important measures in the clinical evaluation of cardiac patients and are also frequently used in research applications. This study was aimed to improve SV scoring derived from spot-electrode based impedance cardiography (ICG) in a pediatric population of healthy volunteers and patients with a corrected congenital heart defect. METHODS: 128 healthy volunteers and 66 patients participated. First, scoring methods for ambiguous ICG signals were optimized to improve agreement of B- and X-points with aortic valve opening/closure in simultaneously recorded transthoracic echocardiography (TTE). Building on the improved scoring of B- and X-points, the Kubicek equation for SV estimation was optimized by testing the agreement with the simultaneously recorded SV by TTE. Both steps were initially done in a subset of the sample of healthy children and then validated in the remaining subset of healthy children and in a sample of patients. RESULTS: SV assessment by ICG in healthy children strongly improved (intra class correlation increased from 0.26 to 0.72) after replacing baseline thorax impedance (Z0) in the Kubicek equation by an equation (7.337-6.208∗dZ/dtmax), where dZ/dtmax is the amplitude of the ICG signal at the C-point. Reliable SV assessment remained more difficult in patients compared to healthy controls. CONCLUSIONS: After proper adjustment of the Kubicek equation, SV assessed by the use of spot-electrode based ICG is comparable to that obtained from TTE. This approach is highly feasible in a pediatric population and can be used in an ambulatory setting.
Authors: Lisette M Harteveld; Nico A Blom; J Gert van Dijk; Robert H Reijntjes; Paul J van Someren; Fabian I Kerkhof; Irene M Kuipers; Lukas A J Rammeloo; Eco J C de Geus; Arend D J Ten Harkel Journal: PLoS One Date: 2022-09-01 Impact factor: 3.752