Computational modelling to optimize the hybrid configuration for hypoplastic left heart syndrome

Andrew Young, Terry Gourlay, Sean McKee, Mark H.D. Danton

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Hybrid palliation for hypoplastic left heart syndrome (HLHS) is associated with mortality and late ventricular dysfunction. Increased ventricular workload and coronary perfusion limitation may be the important factors. Using mathematical modelling, this study investigated the effects of differing hybrid configurations on the demands on this single ventricle circulation.

A multicompartmental Windkessel model of hybrid HLH-aortic atresia
circulation was adopted, with a time-varying elastance representing ventricular
functionality. The effects of diameter increases in bilateral pulmonary artery
bandings (PABs) (+0.5, 2.5-4 mm) and ductal stent (+1, 4-10 mm) on cardiovascular haemodynamics, systemic oxygenation and ventricular energetics were assessed.
Simulations showed that an increase in PAB diameter of 2.5-4 mm resulted
in an increased Q (0.61-2.66), and diastolic stent backflow (-0.2 to -0.78 l/min)
with reduced systemic perfusion (0.82-0.77 l/min) and diastolic pressures
(48.3-41.2 mmHg). Arterial and venous saturations increased, SaO2 (%) was 62-88 and SvO(2) 41-65. To maintain mean systemic pressures, substantial increases in cardiac output (1.3-2.8 l/min) and ventricular stroke work (576-1360 mmHg ml) were required. A decrease in the ductal stent diameter over the range 10-7 mm had a negligible haemodynamic effect: reduced systemic systolic pressure (77-72 mmHg) and increase in ventricular stroke work (781-790 mmHg ml). When the ductal diameter was restricted to <7 mm, it resulted in a significant reduced systemic flow and increased stroke work. Optimal hybrid configuration was defined at PAB 3 mm and ductal stent ≥7 mm.
In this model, increasing the PAB diameter, or a stent diameter <7 mm, substantially increased single ventricle workload and reduced systemic perfusion and diastolic pressure. This may compromise myocardial oxygen demand-supply, particularly in the setting of retrograde-dependent coronary perfusion.
Original languageEnglish
Pages (from-to)664-672
Number of pages9
JournalEuropean Journal of Cardio-Thoracic Surgery
Volume44
Issue number4
Early online date13 Mar 2013
DOIs
Publication statusPublished - Oct 2013

Fingerprint

Hypoplastic Left Heart Syndrome
Stents
Computational Modeling
Stent
Optimise
Perfusion
Configuration
Lung
Stroke
Hemodynamics
Blood Pressure
Workload
Ventricular Dysfunction
Oxygenation
Cardiac Output
Heart
Mm
Oxygen
Pressure
Mortality

Keywords

  • hybrid procedure
  • paediatric heart surgery
  • circulatory modelling

Cite this

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title = "Computational modelling to optimize the hybrid configuration for hypoplastic left heart syndrome",
abstract = "Hybrid palliation for hypoplastic left heart syndrome (HLHS) is associated with mortality and late ventricular dysfunction. Increased ventricular workload and coronary perfusion limitation may be the important factors. Using mathematical modelling, this study investigated the effects of differing hybrid configurations on the demands on this single ventricle circulation.A multicompartmental Windkessel model of hybrid HLH-aortic atresiacirculation was adopted, with a time-varying elastance representing ventricularfunctionality. The effects of diameter increases in bilateral pulmonary arterybandings (PABs) (+0.5, 2.5-4 mm) and ductal stent (+1, 4-10 mm) on cardiovascular haemodynamics, systemic oxygenation and ventricular energetics were assessed.Simulations showed that an increase in PAB diameter of 2.5-4 mm resultedin an increased Q (0.61-2.66), and diastolic stent backflow (-0.2 to -0.78 l/min)with reduced systemic perfusion (0.82-0.77 l/min) and diastolic pressures(48.3-41.2 mmHg). Arterial and venous saturations increased, SaO2 ({\%}) was 62-88 and SvO(2) 41-65. To maintain mean systemic pressures, substantial increases in cardiac output (1.3-2.8 l/min) and ventricular stroke work (576-1360 mmHg ml) were required. A decrease in the ductal stent diameter over the range 10-7 mm had a negligible haemodynamic effect: reduced systemic systolic pressure (77-72 mmHg) and increase in ventricular stroke work (781-790 mmHg ml). When the ductal diameter was restricted to <7 mm, it resulted in a significant reduced systemic flow and increased stroke work. Optimal hybrid configuration was defined at PAB 3 mm and ductal stent ≥7 mm.In this model, increasing the PAB diameter, or a stent diameter <7 mm, substantially increased single ventricle workload and reduced systemic perfusion and diastolic pressure. This may compromise myocardial oxygen demand-supply, particularly in the setting of retrograde-dependent coronary perfusion.",
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Computational modelling to optimize the hybrid configuration for hypoplastic left heart syndrome. / Young, Andrew; Gourlay, Terry; McKee, Sean; Danton, Mark H.D.

In: European Journal of Cardio-Thoracic Surgery, Vol. 44, No. 4, 10.2013, p. 664-672.

Research output: Contribution to journalArticle

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T1 - Computational modelling to optimize the hybrid configuration for hypoplastic left heart syndrome

AU - Young, Andrew

AU - Gourlay, Terry

AU - McKee, Sean

AU - Danton, Mark H.D.

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N2 - Hybrid palliation for hypoplastic left heart syndrome (HLHS) is associated with mortality and late ventricular dysfunction. Increased ventricular workload and coronary perfusion limitation may be the important factors. Using mathematical modelling, this study investigated the effects of differing hybrid configurations on the demands on this single ventricle circulation.A multicompartmental Windkessel model of hybrid HLH-aortic atresiacirculation was adopted, with a time-varying elastance representing ventricularfunctionality. The effects of diameter increases in bilateral pulmonary arterybandings (PABs) (+0.5, 2.5-4 mm) and ductal stent (+1, 4-10 mm) on cardiovascular haemodynamics, systemic oxygenation and ventricular energetics were assessed.Simulations showed that an increase in PAB diameter of 2.5-4 mm resultedin an increased Q (0.61-2.66), and diastolic stent backflow (-0.2 to -0.78 l/min)with reduced systemic perfusion (0.82-0.77 l/min) and diastolic pressures(48.3-41.2 mmHg). Arterial and venous saturations increased, SaO2 (%) was 62-88 and SvO(2) 41-65. To maintain mean systemic pressures, substantial increases in cardiac output (1.3-2.8 l/min) and ventricular stroke work (576-1360 mmHg ml) were required. A decrease in the ductal stent diameter over the range 10-7 mm had a negligible haemodynamic effect: reduced systemic systolic pressure (77-72 mmHg) and increase in ventricular stroke work (781-790 mmHg ml). When the ductal diameter was restricted to <7 mm, it resulted in a significant reduced systemic flow and increased stroke work. Optimal hybrid configuration was defined at PAB 3 mm and ductal stent ≥7 mm.In this model, increasing the PAB diameter, or a stent diameter <7 mm, substantially increased single ventricle workload and reduced systemic perfusion and diastolic pressure. This may compromise myocardial oxygen demand-supply, particularly in the setting of retrograde-dependent coronary perfusion.

AB - Hybrid palliation for hypoplastic left heart syndrome (HLHS) is associated with mortality and late ventricular dysfunction. Increased ventricular workload and coronary perfusion limitation may be the important factors. Using mathematical modelling, this study investigated the effects of differing hybrid configurations on the demands on this single ventricle circulation.A multicompartmental Windkessel model of hybrid HLH-aortic atresiacirculation was adopted, with a time-varying elastance representing ventricularfunctionality. The effects of diameter increases in bilateral pulmonary arterybandings (PABs) (+0.5, 2.5-4 mm) and ductal stent (+1, 4-10 mm) on cardiovascular haemodynamics, systemic oxygenation and ventricular energetics were assessed.Simulations showed that an increase in PAB diameter of 2.5-4 mm resultedin an increased Q (0.61-2.66), and diastolic stent backflow (-0.2 to -0.78 l/min)with reduced systemic perfusion (0.82-0.77 l/min) and diastolic pressures(48.3-41.2 mmHg). Arterial and venous saturations increased, SaO2 (%) was 62-88 and SvO(2) 41-65. To maintain mean systemic pressures, substantial increases in cardiac output (1.3-2.8 l/min) and ventricular stroke work (576-1360 mmHg ml) were required. A decrease in the ductal stent diameter over the range 10-7 mm had a negligible haemodynamic effect: reduced systemic systolic pressure (77-72 mmHg) and increase in ventricular stroke work (781-790 mmHg ml). When the ductal diameter was restricted to <7 mm, it resulted in a significant reduced systemic flow and increased stroke work. Optimal hybrid configuration was defined at PAB 3 mm and ductal stent ≥7 mm.In this model, increasing the PAB diameter, or a stent diameter <7 mm, substantially increased single ventricle workload and reduced systemic perfusion and diastolic pressure. This may compromise myocardial oxygen demand-supply, particularly in the setting of retrograde-dependent coronary perfusion.

KW - hybrid procedure

KW - paediatric heart surgery

KW - circulatory modelling

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DO - 10.1093/ejcts/ezt096

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JO - European Journal of Cardio-Thoracic Surgery

JF - European Journal of Cardio-Thoracic Surgery

SN - 1010-7940

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