Disease severity, arrhythmogenesis, and fibrosis are related to longer action potentials in tetralogy of Fallot.

Functional and structural tissue remodelling may explain arrhythmic activity in TOF patients, even at a very young age. Surprisingly, clinical acyanosis appears to be associated with more severe arrhythmogenic remodelling. Further research into the clinical drivers of structural and electrical myocardial alterations, and the relation between them, is needed to identify predictive factors for patients at risk. Central illustration: summary diagram of essential study results. Note that not all results are depicted here. For more detail, see text. APA action potential amplitude, APD action potential duration, AUC area under the curve, TOF tetralogy of Fallot.