Foetal Advanced Speckle Tracking for the Assessment of Cardiac Function – (FAST – I Study)

Blunt, Carla Elizabeth (2025) Foetal Advanced Speckle Tracking for the Assessment of Cardiac Function – (FAST – I Study). Doctoral thesis (DClinSci), Manchester Metropolitan University.

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Abstract

Introduction: Speckle tracking echocardiography (STE) is an advanced imaging technique used to assess myocardial deformation through global sphericity index (GSI) and global longitudinal strain (GLS). However, its use in foetal cardiology is still limited. This study explores the application of STE in the foetal heart, assessing its feasibility and reproducibility in routine practice and defining normal values across gestational age (GA) groups. Further, ventricular disproportion of the foetal heart is the main indication of an obstructive lesion such as coarctation of the aorta (CoA). However, its diagnosis before birth remains challenging. STE may provide an additional diagnostic marker for the presence of foetal CoA. The primary objective of this study was to evaluate the use of foetal 2D STE in the clinical setting and to assess reproducibility, reliability and clinical applicability. Additionally, this study explores STE’s role in detecting obstructive lesions associated with ventricular disproportion and its potential application in foetal tachyarrhythmia cases. Methods: In a prospective study, using STE, 120 normal foetal four-chamber heart views from 72 participants from 18 to 37 weeks of gestation, 22 studies from 16 foetuses with ventricular disproportion were analysed and compared. Further, seven tachyarrhythmia patients were recruited and a case series was conducted to evaluate the use of STE in this cohort compared to healthy controls. Foetal HQ software was used to assess GSI and GLS of the left ventricle (LV) and right ventricle (RV). Statistical analysis was conducted to assess reproducibility, reliability and to establish normal reference ranges; ventricular disproportion and tachyarrhythmia data were compared against the normal control group. Reference ranges and Z-scores were produced for GSI, LV, and RV GLS across GA groups 19-37 weeks. Results: STE has proven to be a feasible and reliable tool for assessing foetal cardiac function in a clinical setting, with high reproducibility (ICC GSI: 0.93, LV GLS: 0.92, RV GLS: 0.84). A significant relationship was observed between gestational age (GA) and both LV and RV GLS (p < 0.05), Notably RV GLS values were higher than LV GLS with a statistically significant difference (p <0.05). In cases of ventricular disproportion with confirmed obstructive lesions, a significant reduction in LV GLS and GSI was observed compared to normal cohorts (p < 0.05). Similarly in foetuses with tachyarrhythmia, both GSI and LV GLS were significantly reduced compared to controls (p < 0.05). Foetuses with atrial flutter exhibited the lowest GSI values (< 1.1), suggesting potential cardiac remodelling. Conclusion: STE is a reliable tool for foetal cardiac assessment and can be easily incorporated into routine foetal examination with normal reference ranges established here for GSI and LV and RV GLS. Additionally, STE analysis may be a valuable tool for assessing foetuses with ventricular disproportion and could aid in predicting obstructive lesions such as CoA. Furthermore, the use of STE in foetal tachyarrhythmia may offer additional insight into myocardial function before clinical signs of foetal cardiac failure or hydrops develop. However further research is needed to validate its utility in these clinical cases.