Chronic pulmonary regurgitation (PR) after the repair of tetralogy of Fallot (TOF) and other right ventricular outflow tract (RVOT) interventions leads to progressive right ventricular (RV) dilatation, altered ventricular–ventricular interaction, and an increased risk of arrhythmia and heart failure. Pulmonary valve replacement (PVR), whether surgical or transcatheter, effectively eliminates or reduces PR and is associated with short- and mid-term improvement in RV size, symptoms, and electrocardiographic markers. However, the optimal timing of intervention remains unresolved: operating late can result in irreversible myocardial damage and arrhythmogenic substrates, whereas operating early can lead to repeated reinterventions, the impact of which on hard outcomes is uncertain. This review summarizes contemporary evidence on ventricular remodelling after PVR, focusing on cardiovascular magnetic resonance (CMR) and echocardiographic markers, and critically appraises proposed criteria for timing PVR. Classic CMR-derived thresholds (RV end-diastolic volume index [RVEDVi] 150–170 mL/m², RV end-systolic volume index [RVESVi] 80–90 mL/m²) and QRS duration cut-offs are discussed alongside emerging markers of risk, including the RV mass-to-volume ratio, diffuse myocardial fibrosis (extracellular volume fraction), strain imaging, and diastolic dysfunction. Meta-analyses show consistent reverse remodelling and symptomatic benefit after PVR, but no conclusive survival benefit has been demonstrated, and data on arrhythmic outcomes remain conflicting. Key gaps include (i) the lack of prospective randomized or carefully matched comparative studies of “early” versus “deferred” PVR; (ii) limited understanding of how myocardial fibrosis, RV hypertrophy, and diastolic dysfunction interact with volume load and timing to influence long-term outcomes; (iii) under-representation of adult and older adult TOF cohorts; and (iv) insufficient integration of multiparametric risk scores and machine-learning approaches into clinical decision-making. Future research should prioritize multicentre longitudinal cohorts with standardized imaging, electrophysiological and clinical endpoints, incorporate advanced imaging techniques (e.g., strain, 3D late gadolinium enhancement, and T1 mapping), and explore precision-medicine strategies to individualize PVR timing.

Although echocardiography remains the primary imaging modality for assessing Fontan palliation, a standardized systematic approach for evaluating the univentricular heart throughout the different stages of palliation has yet to be established. This document aims to provide a narrative review and practical guide for the echocardiographic assessment of the univentricular heart at various phases of Fontan palliation. Additional objectives include highlighting the potential of advanced three-dimensional (3D) and four-dimensional (4D) imaging modalities, as well as outlining a systematic strategy for detecting thromboembolic complications. We propose a sequential framework for echocardiographic evaluation, encompassing key anatomical and functional components of the univentricular heart. This includes the atrial septum and pulmonary veins, ventricular function, atrioventricular valve, aorta and neo-aorta, sub-aortic region, aortic arch, and pulmonary arteries. Furthermore, we detail the assessment of pulmonary blood supply at different stages of palliation, including the modified Blalock–Taussig–Thomas (mBTT) shunt, Sano conduit, Glenn procedure, and total cavo-pulmonary connection (TCPC). A comprehensive analysis of potential thrombus formation sites is provided, along with diagnostic pitfalls. Additionally, we outline methods for screening for extracardiac clots following Glenn and TCPC procedures. This document serves as a practical guide for the systematic echocardiographic evaluation of the univentricular heart across all stages of Fontan palliation, offering guidance for clinical practice. It also explores the capabilities of emerging 3D and 4D echocardiographic techniques in univentricular heart assessment and provides an in-depth review of thromboembolic complications, emphasizing key diagnostic challenges.

This document has been developed to provide a practical guide for the application of speckle tracking echocardiography (STE) in paediatric and congenital heart diseases. In the present document, the following topics are reviewed and discussed: (i) the basic principles of STE, its potential applications, and limitations in the paediatric population; (ii) normal paediatric reference values for STE; and (iii) the use of STE in various congenital and acquired heart diseases. The potential role of routine STE in the management and follow-up of paediatric and congenital heart disease is explored, with practical examples illustrating how STE can provide additional insights beyond conventional echocardiographic parameters. Limitations regarding clinical interpretation, prognostic value, the lack of standardized timing for measurements, and the absence of universally accepted thresholds for STE-derived strain parameters are also highlighted. Overall, this document is intended to serve as a comprehensive guide to (i) orient clinicians regarding the strengths and limitations of STE in paediatric and congenital heart disease; (ii) identify specific clinical scenarios where STE may be particularly informative; and (iii) encourage future research and multicentre collaborative studies. By providing both practical guidance and a framework for further investigation, the document aims to support standardized use of STE, improve patient care, and foster the integration of this technique into routine paediatric and congenital cardiology practice.