A transmurality evaluation apparatus or probe, method for manufacturing a transmurality evaluation apparatus of probe, and method for assessing the transmurality of a lesion. In one aspect, the transmurality evaluation apparatus or probe generally includes a handheld elongate housing (30), wiring (20) having a first end and a second end, at least one tissue contact (26) electrically coupled to the wiring first end, and a terminal connector (28) electrically coupled to the wiring second end. In another aspect, the method for assessing the transmurality of a lesion generally includes establishing a first electrogram of the first region of tissue, ablating a second region of tissue to form an ablated lesion, establishing a second electrogram of the first region of tissue, and comparing the first and second electrograms to assess transmurality of the ablated lesion.