Effects of local temperature variation on ventricular fibrillation dominant frequency

By inducing controlled changes in the electrophysiologic properties of the whole heart, numerous studies have analysed the onset and maintenance mechanisms of ventricular arrhythmias. In this contribution a new method that cause local heterogeneities in the cardiac tissue is explained. A specific device, based on the Peltier effect, has been developed to quantify, in an experimental model (Langendorff-perfused), the temperature dependence of the dominant frequency (DF) during ventricular fibrillation (VF). This device performs changes of temperature above and below the basal value. With a drop of temperature, a valuable decrease of DF in the affected area, was observed. The differences between every step and control (37/spl deg/C) were significant, and the correlation of DF with temperature was high. At 42/spl deg/C the fibrillation signals showed the main degree of organization, and the highest DF value.