Including Purkinje fibres in digital twin models lengthened VT vulnerability window to 51.67±18.33 ms vs 15±5 ms without and increased multiple reentry circuits.
Does the inclusion of Purkinje fibres in biventricular digital twins affect ventricular tachycardia susceptibility and dynamics?
Incorporating Purkinje fibres into biventricular digital twins significantly extends the arrhythmia vulnerability window and promotes multiple reentry circuits, highlighting their importance in modeling ventricular tachycardia susceptibility.
Absolute Event Rate: 0% vs 0%
Abstract Background Ventricular tachycardia (VT) is a life-threatening arrhythmia often associated with structural heart disease. Computational models, such as biventricular digital twins (BDT), have been increasingly used to study VT mechanisms and optimise treatment strategies. The Purkinje fibre network plays a crucial role in ventricular conduction. Furthermore, discrete Purkinje sources can serve as key triggers for ventricular arrhythmia; however, their specific contribution to the initiation and maintenance of VT remains not fully understood. Purpose This study aims to investigate the role of Purkinje fibres in the generation and sustenance of VT within a BDT framework, providing insights into their electrophysiological (EP) influence on arrhythmogenic substrate and conduction patterns. Methods Personalised BDTs were constructed based on CMR imaging, EGM, and ECG data, incorporating personalised fibre orientation, scar and EP parameters, with explicit modelling of the Purkinje network. BDTs were calibrated using clinical local activation time (LAT) data: the pacing site in BDT was identified using clinical LAT map, as the primary reference point, while a secondary calibration point selected from healthy tissue at the LV basal endocardium, ensuring a scar-free path between the two points. Conductivity of the Purkinje fibres was iteratively adjusted in the BDT to align the LAT at the parameter point with clinical LAT. VT induction was performed under two conditions: with and without Purkinje fibres. Key EP parameters, including reentry circuits and vulnerability window, were analysed to assess the impact of Purkinje fibre activation on VT dynamics (Fig1). Results Three personalised BDTs were developed using clinical data from VT patients. VT induction simulations with and without Purkinje fibres showed that the arrhythmia vulnerability window was longer for BDT with Purkinje fibres (51.67±18.33 ms) and than without (15±5 ms). Reentry circuit analysis showed that multiple reentry circuits formed when Purkinje fibres were included, with a significantly higher number than in the absence of Purkinje fibres. Additionally, variations in Purkinje fibre conductivity influenced VT dynamics; doubling the conductivity shortened the vulnerability window (23.33±8.33 ms) and initiated distinct reentry circuits (Fig2). Conclusions Our findings suggest that Purkinje fibres significantly contribute to VT susceptibility by extending the arrhythmia vulnerability window and promoting multiple reentry circuits. These results highlight the importance of incorporating Purkinje fibre dynamics into computational models for a more accurate assessment of VT risk and evaluation of therapeutic strategies.Study overview Reentry circuits & vulnerability window
Cheng et al. (Sat,) reported a other. Including Purkinje fibres in digital twin models lengthened VT vulnerability window to 51.67±18.33 ms vs 15±5 ms without and increased multiple reentry circuits.