QT dispersion induced by local temperature variations

Abnormally long and short QT intervals (QTi) have been shown to be associated with an increased risk for life-threatening ventricular arrhythmias and sudden cardiac death. Because of its electrophysiological effects temperature can influence this parameter. Therefore hypothermia or/and hyperthermia can be used for modulate QTi in studies with experimental models. In this work, a novel electrode-device to perform epicardial mapping and simultaneous thermal modifications is presented. In ten preparations of isolated rabbit hearts (Langendorff-perfused) changes in QTi was analyzed in two different left ventricular areas. One area was thermally modified, while the other remained in basal conditions, the QTi were measured in both areas. During hypothermia the differences between them increased mainly due to the prolongation of the QTi in altered area. hyperthermia had the opposite effect.