Abnormal initiation and conduction of slow-wave activity in gastroparesis, defined by high-resolution electrical mapping.

Background & Aims Interstitial cells of Cajal (ICC) generate slow waves. Disrupted ICC networks and gastric dysrhythmias are each associated with gastroparesis. However, there are no data on the initiation and propagation of slow waves in gastroparesis because research tools have lacked spatial resolution. We applied high-resolution electrical mapping to quantify and classify gastroparesis slow-wave abnormalities in spatiotemporal detail. Methods Serosal high-resolution mapping was performed using flexible arrays (256 electrodes; 36 cm 2 ) at stimulator implantation in 12 patients with diabetic or idiopathic gastroparesis. Data were analyzed by isochronal mapping, velocity and amplitude field mapping, and propagation animation. ICC numbers were determined from gastric biopsy specimens. Results Mean ICC counts were reduced in patients with gastroparesis (2.3 vs 5.4 bodies/field; P −1 ; P = .002) and increased amplitudes beyond a low base value (415 vs 170 μV; P = .002). Conclusions High-resolution mapping revealed new categories of abnormal human slow-wave activity. Abnormalities of slow-wave initiation and conduction occur in gastroparesis, often at normal frequency, which could be missed by tests that lack spatial resolution. Irregular initiation, aberrant conduction, and low amplitude activity could contribute to the pathogenesis of gastroparesis.