Herein disclosed is a method of detecting and identifying the source of abnormal electrical currents in the heart to assist in ablating these currents, comprising the use of contact or non-contact temperature measurement devices. In an embodiment, source of abnormal electrical activity of the heart and its attached arteries and veins show different temperature patterns from normal segments. In an embodiment, the method further comprises analyzing the temperature of the chamber of interest, and determining regions of low or high temperature by extension metabolic activity. In an embodiment, the method comprises measuring myocardial temperature comprising placing an array of thermocouples imbedded on a basket in the cardiac chamber. In an embodiment, the thermocouples are placed in contact with the myocardial tissue.
