How to assess and treat right ventricular electromechanical dyssynchrony in post-repair tetralogy of Fallot: insights from imaging, invasive studies, and computational modelling.

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.

Natural History of Nonsurgical Complete Atrioventricular Block in Children and Predictors of Pacemaker Implantation.

Background: Data on the natural history of complete atrioventricular block (CAVB) in children are scarce, and criteria for pacemaker (PM) implantation are based on low levels of evidence.

Objectives: This study aimed to evaluate the natural course and predictors of PM implantation in a nationwide cohort of pediatric patients with nonsurgical CAVB.

Methods: All children with CAVB in the absence of structural heart disease presenting from 1977 to 2016 were retrospectively identified, yielding 95 subjects with a mean age of 4.

Influence of fenestration on long-term Fontan survival.

Introduction: Fenestration in the total cavopulmonary connection system may improve the outcome of patients with significant risk factors for Fontan haemodynamics. Our study aims to analyse the difference in long-term survival between non-fenestrated and fenestrated patients.

Methods: All consecutive patients (n = 351) who underwent total cavopulmonary connection between 1992 and 2016 were identified.

Is left bundle branch block pattern on the ECG caused by variable ventricular activation sequence?

Background: The presence and extent of ventricular dyssynchrony are currently assessed from the QRS complex morphology and width. However, similar electrocardiography (ECG) pattern may be caused by variable ventricular activation sequence. This may then contribute to interindividually different response to cardiac resynchronization therapy (CRT).