Gregory O'Grady1, Timothy R Angeli2, Peng Du2, Chris Lahr3, Wim J E P Lammers4, John A Windsor5, Thomas L Abell3, Gianrico Farrugia6, Andrew J Pullan7, Leo K Cheng7. 1. Department of Surgery, University of Auckland, Auckland, New Zealand; Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand. Electronic address: gog@ps.gen.nz. 2. Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand. 3. Division of Gastroenterology, University of Mississippi Medical Center, Jackson, Mississippi. 4. Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Department of Physiology, UAE University, United Arab Emirates. 5. Department of Surgery, University of Auckland, Auckland, New Zealand. 6. Division of Enteric Neurosciences, Mayo Clinic, Rochester, Minnesota. 7. Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Department of Surgery, Vanderbilt University, Nashville, Tennessee.
Abstract
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 < .001). Slow-wave abnormalities were detected by high-resolution mapping in 11 of 12 patients. Several new patterns were observed and classified as abnormal initiation (10/12; stable ectopic pacemakers or diffuse focal events; median, 3.3 cycles/min; range, 2.1-5.7 cycles/min) or abnormal conduction (7/10; reduced velocities or conduction blocks; median, 2.9 cycles/min; range, 2.1-3.6 cycles/min). Circumferential conduction emerged during aberrant initiation or incomplete block and was associated with velocity elevation (7.3 vs 2.9 mm s(-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.
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 < .001). Slow-wave abnormalities were detected by high-resolution mapping in 11 of 12 patients. Several new patterns were observed and classified as abnormal initiation (10/12; stable ectopic pacemakers or diffuse focal events; median, 3.3 cycles/min; range, 2.1-5.7 cycles/min) or abnormal conduction (7/10; reduced velocities or conduction blocks; median, 2.9 cycles/min; range, 2.1-3.6 cycles/min). Circumferential conduction emerged during aberrant initiation or incomplete block and was associated with velocity elevation (7.3 vs 2.9 mm s(-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.
Authors: Thomas L Abell; Michael Camilleri; Kevin Donohoe; William L Hasler; Henry C Lin; Alan H Maurer; Richard W McCallum; Thomas Nowak; Martin L Nusynowitz; Henry P Parkman; Paul Shreve; Lawrence A Szarka; William J Snape; Harvey A Ziessman Journal: Am J Gastroenterol Date: 2007-11-19 Impact factor: 10.864
Authors: Peng Du; G O'Grady; J U Egbuji; W J Lammers; D Budgett; P Nielsen; J A Windsor; A J Pullan; L K Cheng Journal: Ann Biomed Eng Date: 2009-02-18 Impact factor: 3.934
Authors: Wim J E P Lammers; Luc Ver Donck; Betty Stephen; Dirk Smets; Jan A J Schuurkes Journal: Gastroenterology Date: 2008-07-22 Impact factor: 22.682
Authors: Timothy R Angeli; Peng Du; Niranchan Paskaranandavadivel; Patrick W M Janssen; Arthur Beyder; Roger G Lentle; Ian P Bissett; Leo K Cheng; Gregory O'Grady Journal: J Physiol Date: 2013-05-27 Impact factor: 5.182
Authors: Jerry Gao; Peng Du; Greg O'Grady; Rosalind Archer; Gianrico Farrugia; Simon J Gibbons; Leo K Cheng Journal: J R Soc Interface Date: 2013-06-26 Impact factor: 4.118