Computer modelling of cardiac repolarisation

The origin of the T wave shape, the electrocardiographic manifestation of left ventricular repolarisation, is still unclear. No explanation has been given for its asymmetrical shape and upright orientation in normal subjects and its tall, symmetrical shape with inverted orientation commonly observed in heart pathologies. In this study a new and simple mathematical model of repolarisation of the left ventricle and of the associated body potentials is proposed. By choosing three different repolarisation sequences for the left ventricle, T waves with normal orientation and with pathologically inverted orientation were simulated. Using a normal experimental repolarisation sequence, the T waves in the simulated 12 lead ECG appeared as in normal subjects. Inverted, tall and symmetrical T waves were obtained using two abnormal repolarisation sequences (inverted epicardial repolarisation, inverted transmural repolarisation) increasing the value of dispersion towards 150 ms. Results from this work strongly suggest that the origin of tall, symmetrically: inverted T waves are an increased dispersion of repolarisation in the left ventricle and an abnormal repolarisation sequence