BACKGROUND AND AIMS: Right bundle branch block (RBBB) and resulting right ventricular (RV) electromechanical discoordination are thought to play a role in the disease process of subpulmonary RV dysfunction that frequently occur post-repair tetralogy of Fallot (ToF). We sought to describe this disease entity, the role of pulmonary re-valvulation, and the potential added value of RV cardiac resynchronization therapy (RV-CRT). METHODS: Two patients with repaired ToF, complete RBBB, pulmonary regurgitation, and significantly decreased RV function underwent echocardiography, cardiac magnetic resonance, and an invasive study to evaluate the potential for RV-CRT as part of the management strategy. The data were used to personalize the CircAdapt model of the human heart and circulation. Resulting Digital Twins were analysed to quantify the relative effects of RV pressure and volume overload and to predict the effect of RV-CRT. RESULTS: Echocardiography showed components of a classic RV dyssynchrony pattern which could be reversed by RV-CRT during invasive study and resulted in acute improvement in RV systolic function. The Digital Twins confirmed a contribution of electromechanical RV dyssynchrony to RV dysfunction and suggested improvement of RV contraction efficiency after RV-CRT. The one patient who underwent successful permanent RV-CRT as part of the pulmonary re-valvulation procedure carried improvements that were in line with the predictions based on his Digital Twin. CONCLUSION: An integrative diagnostic approach to RV dysfunction, including the construction of Digital Twins may help to identify candidates for RV-CRT as part of the lifetime management of ToF and similar congenital heart lesions.

• Keywords
• Cardiac resynchronization therapy, Digital Twin, Right bundle branch block, Right ventricular dysfunction, Tetralogy of Fallot,
• MeSH
• Bundle-Branch Block diagnostic imaging   etiology   therapy   MeSH
• Ventricular Dysfunction, Right * diagnostic imaging   etiology   therapy   MeSH
• Echocardiography MeSH
• Tetralogy of Fallot * diagnostic imaging   surgery   MeSH
• Humans MeSH
• Computer Simulation MeSH
• Heart Ventricles MeSH
• Cardiac Resynchronization Therapy * adverse effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

• Keywords
• Accessory pathway ablation, Cone repair, Congenital heart disease, Cryoablation, Ebstein’s anomaly, Right ventricular cardiac resynchronization therapy, Wolff-Parkinson-White syndrome,
• Publication type
• Journal Article MeSH
• Case Reports MeSH

BACKGROUND: A biomechanical model of the heart can be used to incorporate multiple data sources (electrocardiography, imaging, invasive hemodynamics). The purpose of this study was to use this approach in a cohort of patients with tetralogy of Fallot after complete repair (rTOF) to assess comparative influences of residual right ventricular outflow tract obstruction (RVOTO) and pulmonary regurgitation on ventricular health. METHODS: Twenty patients with rTOF who underwent percutaneous pulmonary valve replacement (PVR) and cardiovascular magnetic resonance imaging were included in this retrospective study. Biomechanical models specific to individual patient and physiology (before and after PVR) were created and used to estimate the RV myocardial contractility. The ability of models to capture post-PVR changes of right ventricular (RV) end-diastolic volume (EDV) and effective flow in the pulmonary artery (Qeff) was also compared with expected values. RESULTS: RV contractility before PVR (mean 66 ± 16 kPa, mean ± standard deviation) was increased in patients with rTOF compared with normal RV (38-48 kPa) (P < 0.05). The contractility decreased significantly in all patients after PVR (P < 0.05). Patients with predominantly RVOTO demonstrated greater reduction in contractility (median decrease 35%) after PVR than those with predominant pulmonary regurgitation (median decrease 11%). The model simulated post-PVR decreased EDV for the majority and suggested an increase of Qeff-both in line with published data. CONCLUSIONS: This study used a biomechanical model to synthesize multiple clinical inputs and give an insight into RV health. Individualized modeling allows us to predict the RV response to PVR. Initial data suggest that residual RVOTO imposes greater ventricular work than isolated pulmonary regurgitation.

CONTEXTE :: Une modélisation biomécanique du cœur peut être utilisée pour intégrer des sources de données multiples (électrocardiographie, imagerie, hémodynamique invasive). Le but de cette étude était d’utiliser cette approche pour une cohorte de patients atteints de tétralogie de Fallot aprèsr réparation complète (TdFr) pour évaluer, au niveau du ventricule, les influences comparatives de la sténose résiduelle de la voie d’éjection du ventricule droit (SVEVD) et de la régurgitation pulmonaire. MÉTHODES :: Vingt patients atteints de TdFr ayant subi un remplacement percutane de la valve pulmonaire (RVP) et une imagerie par résonance magnétique cardiovasculaire ont été inclus dans cette étude rétrospective. Des modèles biomécaniques adaptés à chaque patient et à sa physiologie (avant et après le RVP) ont été créés et utilisés pour estimer la contractilité myocardique du ventricule droit (VD). La capacité des modèles à capturer les changements post-RVP du volume télédiastolique (VTD) du VD et du débit effectif dans l’artère pulmonaire (Qeff) a également été comparée aux valeurs attendues. RÉSULTATS :: La contractilité du VD avant le RVP (moyenne 66 ± 16 kPa, moyenne ± déviation standard)) était plus élevée chez les patients atteints de TdFr par rapport au VD normal (38–48 kPa) (P < 0,05). La contractilité a diminué de manière significative chez tous les patients après le RVP (P < 0,05). Les patients présentant une SVEVD prédominante ont montré une plus grande réduction de la contractilité (diminution médiane de 35 %) après le RVP que ceux présentant une régurgitation pulmonaire prédominante (diminution médiane de 11 %). Le modèle a simulé une diminution du VTD-VD après le RVP pour la majorité des patients et a suggéré une augmentation du Qeff, ce qui est conforme aux données publiées. CONCLUSIONS :: Cette étude a utilisé un modèle biomécanique pour synthétiser de multiples données cliniques et donner un aperçu de l’état de santé du VD. La modélisation individualisée nous permet de prédire la réponse du VD au RVP. Les premières données suggèrent que la SVEVD résiduelle impose un travail ventriculaire plus important que la régurgitation pulmonaire isolée.

• MeSH
• Models, Biological * MeSH
• Heart Valve Prosthesis Implantation methods   MeSH
• Adult MeSH
• Tetralogy of Fallot surgery   MeSH
• Hemodynamics physiology   MeSH
• Pulmonary Valve Insufficiency congenital   diagnosis   surgery   MeSH
• Cardiac Surgical Procedures methods   MeSH
• Humans MeSH
• Magnetic Resonance Imaging, Cine MeSH
• Abnormalities, Multiple * MeSH
• Follow-Up Studies MeSH
• Pulmonary Valve abnormalities   diagnostic imaging   surgery   MeSH
• Reoperation MeSH
• Retrospective Studies MeSH
• Heart Ventricles diagnostic imaging   physiopathology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Observational Study MeSH
• Research Support, Non-U.S. Gov't MeSH