A Computational Model of the Canine Pulmonary Veins Sleeves

The cellular electrophysiological properties of the pulmonary vein sleeves (PVS), the intersection between pulmonary veins and left atrium, were reported few decades ago. However, the clinical significance of pulmonary vein sleeves was not found until recently. In patients with atrial fibrillation, it was found that ectopic foci existed in the pulmonary vein sleeves. Therefore, electrophysiological studies on PVS have drawn a lot of attention recently. For example, in the experiments of dogs and rabbits, besides the fast response type of action potential, various pacemakerlike automaticities and triggered activities, e.g., early afterdepolarizations (EAD), delayed afterdepolarizations (DAD), have been demonstrated in the PVS under physiological or pathophysiological situations (see [Hocini et al., 2002], [Ehrlich et al., 2003], [Hojo et al., 2003], [Wang et al., 2003, 2005], [Po et al., 2005], [Chen et al., 2000, 2001, 2002-a, 2002-b, 2002-c, 2003-a, 2003-b, 2003-c, 2004-a, 2004-b]). In this study, we have developed a mathematical model which fits well the experiments for the canine PVS in [44]. Using this model, besides the normal response of the PVS cells we have also successfully reproduced the experimentally observed frequency responses and ischemia/hyperkalemia phenomena.