Figure 2 (A). Ablation catheter with three microelectrodes (MEs) circumferentially equipped on the distal tip (Qdot MicroTM; Biosense Webster, Diamond Bar, California).
(B) The standard bipolar electrode and MEs in contact with the tissue. Note that the signals were detected by both the standard bipolar electrode and MEs (arrow heads).
(C) The catheter in contact with the tissue parallelly, leading to a lack of contact between the MEs and the tissue. Note that the near-field signals were detected by the standard bipolar electrode (arrow heads) without detection of any corresponding signals by the ME. Abbreviations as in Figure 1.