Optimal cardiac resynchronization therapy: an in-silico investigation using a whole-heart model

Cardiac resynchronization therapy (CRT) is indicated in patients with heart failure and consists of the implantation of a pacemaker to restore the coordination of ventricles contraction. However, in one-third of the patients CRT fails to improve clinical parameters owing to the sub-optimal position of the pacing leads, which can be improved by running dedicated clinical trials. However, the recruitment of patients is a bottleneck for clinical trials and digital twins of the human heart have recently been proposed as a viable alternative. In this study, we rely on an unprecedented cardiovascular numerical model which is GPU–accelerated to replicate the full cardiac dynamics within a few hours. Specifically, cardiac dyssynchrony is induced by blocking the left bundle branch in the electrophysiology system, which yields a delay in the electrical activation of the ventricular myocardium and a reduced ejection fraction. A CRT is then implanted in-silico by mounting three leads: one in the right atrium, one in the right ventricle and another in the left ventricle. The optimal positioning of the last lead is determined by considering several pacing sites across the coronary venous system. The numerical results confirm the reliability of the method, thus moving towards an effective use of multiphysics modelling in digital medicine.