Arterial elastance and its impact on intrinsic right ventricular function in palliated hypoplastic left heart syndrome
Introduction
The right ventricle (RV) is not built to permanently withstand systemic afterload and fails prematurely when working as the systemic ventricle [1]. Arterial vascular load is the major determinant of ventricular afterload and reflects the properties of the vascular bed mainly the distensibility of the great arteries and peripheral vascular resistance. Arterial vascular load can be measured in a simplified way as arterial elastance (Ea), the steady-state ratio of end systolic pressure and stroke volume obtained from the pressure–volume loop [2]. Ea has been shown to be a useful marker to assess the impact of arterial vascular load on the human ventricle [3].
Extensive reconstructive surgery to the aortic arch using patch material is part of the first step of surgical palliation of hypoplastic left heart syndrome (HLHS) and data from non-invasive imaging studies suggest increased stiffness with decreased distensibility of the neo-aorta [4], [5]. We therefore thought to assess Ea in palliated HLHS patients and to relate this marker of ventricular afterload to ventricular function, especially to intrinsic, load independent function of the systemic RV. Furthermore, because aortic arch obstruction can complicate surgical palliation of HLHS and has been shown to acutely affect RV function we paid particular attention to this patient group [6].
Section snippets
Patients
72 consecutive patients with HLHS after the fenestrated lateral tunnel Fontan procedure were recruited to be studied with the pressure–volume conductance system between January 2005 and March 2011. Conductance data should be obtained during a routine cardiac catheterisation procedure. In 16 patients conductance data could not be analysed due to either poor signal quality or failure to correctly place the catheter in the RV. Therefore, functional data are available in 56 patients.
All except 3
Patient characteristics
Patient characteristics, surgical data and data on the functional result of aortic arch reconstruction are summarised in Table 1. Patients were studied at a median of 2.6 years after Fontan completion. There was no significant stenosis at the site of the reconstructed aortic arch at the time of the conductance catheter study.
Conductance derived data on ventriculo-arterial coupling
Data on RV function at baseline measurement and during dobutamine infusion are given in Table 2.
Cardiac index increased with dobutamine infusion as heart rate increased,
Discussion
The present study demonstrates that arterial elastance (Ea) is abnormally high in children with HLHS who underwent the Norwood operation and is associated with an increase in diastolic stiffness. Furthermore, it shows that Ea and diastolic stiffness are particularly elevated in patients who needed treatment of aortic arch obstruction albeit that treatment has been successful.
Conclusion
Arterial elastance, the major determinant of ventricular afterload, is abnormally high in palliated HLHS patients and negatively impacts on ejection fraction but not on load independent systolic myocardial function. Diastolic stiffness, however, is increased when aortic elastance is high.
The effects of abnormal arterial elastance on intrinsic systolic function and diastolic stiffness were more pronounced in patients who underwent successful treatment for aortic coarctation. Thus, prevention,
Funding
This work and the Department of Paediatric Cardiology, Kiel, were supported by the Fördergemeinschaft Deutsche Kinderherzzentren e.V.
Acknowledgement
The expert technical assistance of T. Hansen and A. Wegmann is gratefully acknowledged.
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2022, Journal of Thoracic and Cardiovascular SurgeryDiastolic inflow is associated with inefficient ventricular flow dynamics in Fontan patients
2022, Journal of Thoracic and Cardiovascular SurgeryCitation Excerpt :Novel catheterization techniques and echocardiographic study have sought to account for this differential in the assessment of ventricular function comparing load-dependent and load-independent conditions.31 This prior study demonstrated that while intrinsic systolic function is increased in the single right ventricle early after Fontan-palliation when compared with non-Norwood single left ventricles, ventricular elastance–myocardial stiffness is significantly increased and implicates the aortic reconstruction as a principal determinant of afterload-mediated myocardial remodeling and functional longevity.7,32 Our study provides further insight into the relative function of the single left versus single right systemic ventricle demonstrating that patients with HLHS have significantly increased end-diastolic and end-systolic volume indices compared with both HRHS and control patients.
Echocardiographic assessment of ventricular function: Conventional and advanced technologies and their clinical applications
2020, Progress in Pediatric CardiologyCitation Excerpt :Rosner et al. reported that a classicpattern of dyssynchrony was noted in 15% of 100 Fontan patients; it was commonly associated with more dilated ventricles with reduced systolic and diastolic function [72]. Increased aortic stiffness and afterload due to aortic arch reconstruction also affects ventricular performance [73]. Commonly used methods include annular plane displacement, systolic-to-diastolic time duration ratio, peak systolic annular velocity (S′), and longitudinal and circumferential strain measurements in single RV and traditional methods of LV function assessment in single LV.
Geometry and growth of the reconstructed aorta in patients with hypoplastic left heart syndrome and variants
2017, Journal of Thoracic and Cardiovascular SurgeryCitation Excerpt :Attention has therefore shifted toward reduction of interstage morbidity and mortality, better neurodevelopment, and improvement of long-term outcome in general.16,17 The reconstruction of the hypoplastic aorta and especially aortic obstruction have been identified as factors that influence outcome significantly.1,4 A multitude of variations have therefore been developed to ensure adequate enlargement of the aorta and to reduce the rate of recoarctation.7,8,12,13,18
Ventricular function and ventriculo-arterial coupling after palliation of hypoplastic left heart syndrome: A comparative study with Fontan patients with LV morphology
2017, International Journal of CardiologyCitation Excerpt :Since the RV in HLHS is subjected to volume and pressure overload without interruption since the neonatal period, myocyte hyperplasia might be present in these ventricles and this may well be one of the adaptive mechanisms contributing to preservation of contractility throughout and beyond the period of Fontan palliation. Our group has previously shown that ventriculo-arterial coupling is preserved in patients with HLHS early after Fontan completion [5]. Now we report a similar finding for paediatric Fontan patients with both, right and left ventricular morphology and with and without aortic arch reconstruction.