Thick-film multielectrode device for thermal modifications in isolated heart experiments

Previous works have been focused in studying the effects of global temperature changes on the heart. In this contribution a new method to cause thermal modifications in only a limited area of the cardiac tissue, and its experimental application, are explained. The developed device, based on thick-film technology and Peltier effect, was applied to quantify the temperature dependence of electrophysiological parameters in isolated rabbit hearts (Langendorff-perfused). The thermal changes were efficiently achieved in a short time and with sufficient precision. We obtained valuable information about how the local temperature affects the refractoriness, conduction velocity, or activation frequency during constant stimulation or ventricular fibrillation (VF).