Effects of electrode size and spacing on the resolution of intracardiac electrograms

Abstract

Our calculations suggest that if electrodes could be constructed to have negligible dimensions compared with those in use today, we would increase resolution by about one order of magnitude at most.

High-Resolution Mapping of Ventricular Scar

“…16 In more recent work, Stinnett-Donnelly, et al showed using computational and in-vitro models that resolution is impacted by electrode size, interelectrode spacing, and distance from the source. 17 …”

Three‐dimensional myocardial scar characterization from the endocardium: Usefulness of endocardial unipolar electroanatomic mapping

“…1,4 BP EGMs are constructed from two UNIP signals generated from two electrodes typically separated by several millimeters, a configuration that results in a narrower "field of view" of the BP signal when compared with the UNIP signal construction. 1,[7][8][9][10][11][12][13][14][15] In the case of UNIP mapping, such variables may influence both the endo UNIP absolute voltage and the initial polarity of the UNIP signal. This phenomenon of remote signal attenuation justifies why BP mapping is preferred over UNIP mapping to characterize the myocardial tissue contiguous to the mapping catheter.…”

“…In the clinical scenario of ventricular tachycardia (VT) ablation, this phenomenon would explain why some low amplitude endo BP late potentials indeed belong to ventricular sites at a distance of up to a centimeter and can only be eliminated by epi ablation. 9 In an animal model evaluating BP and UNIP EGM characteristics using microelectrodes embedded at the catheter tip, UNIP EGM amplitude was significantly lower in areas of normal tissue recorded with the microelectrodes in comparison to the standard 3.5-mm electrode, 5.7±2.3 mV (median 5.2 mV) vs 8.2 ±2.9 mV (median 7.8 mV), respectively, with the fifth percentile also lower with microelectrodes (2.9 vs 4.1 mV). 1,[7][8][9][10][11][12][13][14][15] In the case of UNIP mapping, such variables may influence both the endo UNIP absolute voltage and the initial polarity of the UNIP signal.…”

“…1,[7][8][9][10][11][12][13][14][15] In the case of UNIP mapping, such variables may influence both the endo UNIP absolute voltage and the initial polarity of the UNIP signal. 9,15 Far-field signals usually have lower frequency content than nearfield signals, and thus high-pass filtering at 30 Hz up to 100 Hz (instead of the minimally filtered UNIP signal at 0.5-2 Hz) may attenuate the contribution of remote activity to the UNIP EGM ( Figure 2). 7,13 The ability to pick up distant myocardial disease during UNIP mapping with small electrodes from closely spaced multielectrode catheters remains a matter of controversy and requires additional study and validation.…”

Cardiac mapping and pulmonary vein isolation using a novel ablation catheter with tip minielectrodes

“…It has been previously described by our study group and others that spatial resolution of catheters highly depends on electrode size and interelectrode spacing. 7,13,14 Identification of myocardial substrate and crucial ablation spots depends on the catheter and the electrode configuration. The extend of left atrial lesions is correlated to cerebral lesions and injury of atrial wall.…”