Overdrive Pacing Assimilation in a Personalized Human Heart Model

The key feature of the heart muscle is its electrical activity since it manages the myocardium contraction and the entire heart pump function. Heart rhythm disturbances such as paroxysmal tachycardia can be life-threatening and thus must be treated immediately. Overdrive pacing is a novel out-of-hospital low-voltage way of heart electrotherapy and is simulated in the present paper. DT-MRI data is used to construct a volumetric model of the cardiac left ventricle. A two-variable cell-level model and a fibers direction model are incorporated to calculate electrical excitation in the anisotropic tissue. A scroll wave is created first to simulate ventricular tachycardia. Low-energy overdrive pacing is applied then to shift the scroll wave toward the fibrous ring, where it disappears. This will stop the re-entry and treat the arrhythmia. The interval of effective pacing periods is determined with the use of different electrodes. The cycle lengths are measured at a detector and analyzed to elucidate the rhythm assimilation. The pacing was successful despite the Mobitz effect in some cases.