Su1451 Dynamic Antral Scintigraphy Identifies Patterns of Gastric Contractility in Patients With Upper GI Motility Disorders: Comparison to Conventional Gastric Emptying Scintigraphy Data

Abstract

Introduction. Diabetic gastroparesis is defined as delayed gastric emptying not caused by obstruction or structural abnormality. Normal function of the gastric and intestinal mechanical activity is mediated by slow wave electrical activity in the stomach and small bowel. Previous studies using both electrogastrogram and magnetogastrogram have shown gastric slowwave dysrhythmias associated with gastroparesis, but no study has yet examined possible effects of gastroparesis on the intestinal slow wave. Methods. We recorded intestinal slow waves in diabetic patients with gastroparesis (N=7) and healthy controls (N=7) using the magnetoenterogram (MENG), which uses a Superconducting QUantum Interference Device (SQUID) to convert magnetic fields associated with intestinal slow waves into voltage signals. Second Order Blind Identification (SOBI) was used to reduce noise and isolate the intestinal slow wave signal from confounding magnetic artifact, and we computed the power spectrum of the intestinal slow wave using a Fast Fourier Transform technique. We analyzed dominant frequency, amplitude and percentage of power distributed (PPD) in brady, normo and tachyarrhythmic frequency ranges. Results. In gastroparesis patients, we found a significant decrease in postprandial dominant intestinal slow wave frequency from 10.2 ± 0.4 cpm to 8.8 ± 0.5 cpm (p<0.05) whereas the dominant frequency for control subjects increased from 9.9 ± 0.5 cpm to 10.8 ± 0.4 cpm (p<0.05). We did not observe significant differences in preand postprandial PPDs computed from controls or patients. Conclusions. Diabetic gastroparesis is associated with bradyarrhythmia, but not uncoupling, of the intestinal slow wave. Biomagnetic measurements of the MENG can assess intestinal slow wave activity in healthy and diseased tissue noninvasively.