Background: Hypoplastic left heart syndrome (HLHS) describes a spectrum of underdevelopment of the left heart, rendering it incapable of supporting the systemic circulation. Improved results from Norwood palliation mean more children are surviving into later childhood. The assessment of right ventricular (RV) function is an important prognostic factor, but is complicated by wide heterogeneity and complex geometry. Novel MRI and echocardiographic techniques are non-invasive and may offer insight into the pathophysiology of the systemic RV. Methods: Current methods for assessing the RV were reviewed. MRI and echocardiography were used and compared prospectively in HLHS patients to investigate RV performance and changes in ventricular volumetry across the palliative stages. The novel approach of pre-Fontan assessment using MRI and central venous pressure (CVP) measurement alone was compared to the current literature. Results: Echocardiographic subjective assessment of RV function in HLHS had little concordance with MRI ejection fraction, showing the limitation of using this method alone. MRI demonstrated significant RV volume unloading after hemi- Fontan, with a shift of the Starling curve suggesting improved contractility. The novel pre-Fontan assessment showed no difference in outcomes from the published literature. Tissue Doppler time intervals were significantly different in HLHS patients compared to normal hearts. Differences were also seen in tissue Doppler indices and speckle tracking derived strain between those with a significant residual left ventricle and those without Conclusions: Novel MRI and echocardiographic techniques give unique and reproducible insights into the morphologic and functional development of the systemic RV across the stages of surgical palliation. Important differences between the morphological subtypes were also noted. Based on this MD thesis, reliable, easy to use, reproducible and non-invasive screening tools have been established, validated and used for longitudinal follow-up. These techniques may also lead to improved follow-up: predicting, or possibly preventing systemic RV failure.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:646962 |
| Date | January 2013 |
| Creators | Bellsham-Revell, Hannah |
| Contributors | Greil, Gerald; Simpson, John |
| Publisher | King's College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://kclpure.kcl.ac.uk/portal/en/theses/pathophysiology-of-the-systemic-right-ventricle-in-hypoplastic-left-heart-syndrome(62ed8eec-549c-4e58-88c7-60a2a959f7e6).html |
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