Activation Time Determination by High‐Resolution Unipolar and Bipolar Extracellular Electrograms in the Canine Heart

摘要: Activation Time Determination by High-Resolution Electrograms. Introduction: To identify the optimal criteria for activation time (AT) determination of bipolar electrograms from normal hearts, a high-resolution cross electrode array comprising 128 unipolar electrodes 500-μm spacing was used to record extracellular potentials left ventricular epicardium 12 dog hearts. Methods and Results: Recordings were made during broad wavefront propagation (B wave) local elliptical (E wave). Characteristics 863 (1-mm spacing) constructed data standardized differences in polarity, then classified morphologically. Features AT compared negative peak firrst temporal derivative electrogram situated mid-way between bipoles. During B wave, three distinct morphologies observed: unipbasic (61%), biphasic (23%), triphasic (16%). Peak voltage uniphasic signals best predictor (error: 0.6 ± msec 0.8 msec, respectively). E parallel orientation bipoles with respect direction impulse resulted (> 99%), while perpendicular bipoles, morphology variable. For both longitudinal transverse propagation, bipole orientation, less reliable along fiber axes. Increasing interpolar distance degradation accuracy wave (from at 1 mm 1.1 1.2 7 mm) 0.4 0.3 3.1 2.9 mm). Conclusions: (1) The is sensitive direction, distance; (2) AT, but only wave; (3) maximum 2 are minimally required accurate initiated near recording electrodes; (4) impulses site tissue, bipbasic or almost certainly indicates that oriented irrespective orientation.