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Cyclic frequency variations: A new characteristic of gastric myoelectric activity
October
ABSTRACTS
1994
IS DIABETIC GASTROPARESIS (DG) ASSOCIATED WITH VAGAL OR NONVAGAL AUTONOMIC NEUROPATHY? JS Rew ST Lee, RC Glena, JJ Hsu, WY Chey, CH Kim. Eof Medicine, University of Rochester, Rochester, NY. Vagal autonomic neuropathy has been implicated as a major pathogenetic mechanism of DG; however, the exact site of cholinergic dysfunction remains unknown. Aim: To determine whether or not cholinergic defect seen in DGis vagal or nonvagal. Methods: We studied 4 pts. with DG (mean age: 25.8 yrs) and 5 healthy controls (mean age: 37.8 yrs). Vagal and nonvagal cholinergic function were assessed by pancreatic polypeptide (PP) responses to insulin-induced hypoglycemia (Regular-Insulin, 3OmU/M’/min: J Clin Invest 61:781, 1978) and to bolus injection of secretin Q&kg: J Clin Endocrinol Metab 50:1094, 1980), respectively. PP was measured by radioimmunoassay. &&g: PP responses to secretin and insulin-induced hypoglycemia in DG were similar to the responses noted in the control group. However, the pattern of PP response in DG was highly variable (see Table).
Controls (n=5)
Cholinernic Vagal (+)
Diabetic Gastroparesis Case 1 Case 2 Case 3 Case 4
(+) (+) (-) (-)
(+) normal response
Inteerity Nonvaeal (+)
(+) (+) (+) (-)
(-) impaired response
Conclusions: Our results suggest that 1) DG is not necessarily associated with cholinergic dysfunction and 2) the cholinergic defect seen in DG is heterogeneous.
PACESETTER POTENTIAL CONDUCTION VELOCITY PREDICTS ROUX-EN-Y FUNCTIONAL ACTIVITY. sJDZ Chen, X. Yi, B. Schirmer. Depts. Liao -I UniInternal Medicine, and of Surgery versity of VA, Charlottesville, VA myoelectric Various abnormalities of activity are associated with the symptoms of We investigated which "ROUX limb syndrome." myoelectric parameters most closely correlated with the recovery of Roux limb funcRecordings tion from postoperative ileus. Roux limb patients undergoing of eight creation and intraoperative placement of bipolar seromuscular electrodes were obtained daily during the first week following surgery then weekly until one month postopThere were no significant diferatively. potential pacesetter ferences in the frequencies, amplitudes, or the percentage of pacesetter potentials with associated spike potentials when comparing tracings from postoperative day (POD) 1 to one month. velocity However, pacesetter conduction increased significantly from POD 1 to 7 (0.745.27 to 1.755.65 cm/set, p<.O5), and showed no significant increase thereafter to one month (2.02k.62 set). Conduction velocity correlated significantly with postoperative days 1 to 7 (r=.874, p=.OO4) and cliniConduction cal recovery of bowel function. velocity appears to be the most accurate parameter with which to measure recovery of Roux limb function from postoperative ileus, and may be an important parameter to measure in clther motility disorders.
OF
PAPERS
CYCLIC FREQUENCY VARIATIONS: A NEW CHARACTERISTIC OF GASTRIC MYOELECTRIC ACTIVITY. P. Zacchi Deutschbein, R. Kuhlbusch, P. Auer, H. J. Lfibke. P. Enck. H&rich Heine Hospitals, Dept. of University Gastmenterology, Dtlsseldorf, Germany. We previously demonstrated cyclic frequency changes of gastric myoelectric activity in newborns (J Gastrointest Mot 5, lQQ3:227), but no data exist on gastric frequency pattern in adults. It is well known that cyclic frequency variations occur in the heart, which are regulated by autonomic nervous system. Our aim was to verify the presence of gastric cyclic frequency variations in adults and to correlate them to variations of heart rate. METHODS. We studied 6 healthy female subjects (mean age 26 yrs, range 23-37 yrs). Electrogastrography was performed for 90 min before and 90 min after a solidlliouid meal. usina a oair of bioolar electrodes oositioned over the stomach. Data we~reconied onto a tape recorder for offline analysis of the frequency spectrum performed by a Fast Fourier Transformation. Minute-to- minute identification of the dominant frequency was performed. Median values for consecutive 5 minute intervals were calculated and plotted over the time to visually identifv cvclic variation and to calculate the variation coefficient of the dominant frequency. Conventional electrocardiogram was performed in all subjects in supine position. Beat-to-beat frequency variations were identified by a computerized electmcardiograph (ProSciCard System, MedySyst, Linden, Germany). and a variation coefficient was calculated. RESULTS.1) Gastric mean dominant frequency was 0.0437 + 0.005 Hz (mean + SD) preprandially and 0.0443 +,0.005 Hz during postprandial period. 2) A cyclic change of the gastnc dominant frequency was detected in 7/8 subjects during preprandial period and in 616 subjects postprandially; the cycle length was not significantly different between both periods (26.1 + 7.2 min and 24.19 + 10.27 min, respectively). 3) The variation coefficient of gastric cyclic activity was lower, but not significantly. before than after the meal (14.1 + 5.7% and 21.4 + 6.4%. respectively). 4) The variability of heart frequency and of gastric frequency of preprandial period was not significantly correlated (6.2 + 1 .Q% and 14.1 + 5.7% respectively; p>O.O5). CONCLUSION. Gastric electric activity in adults exhibits frequency variations which were, uptoday. never demonstrated. This cyclic activity is not disrupted by the meal. The wntml mechanisms of this activity might be related to those regulating heart rate variability. (Supported by a grant from Deutsche Forschungsgemeinschafl, EN 50/l 0).
DETERMINATION OF RESPIRATORY MOVEMENT OF THE ESOPHAGEAL SPHINCTER FROM MANDMETRIC DATA.
LOWER
J.A. Rinaldo Jr.. J.H. Steinbach. S. Zamani. G. GosseQ, A. Babaknia. N. Izima. M. Barn University of California and VA Medical Center, San Diego, California and Providence Hospital, Southfield, Michigan. In the opossum, all of the lower esophageal sphincter [LES] is in the abdominal cavity. However, during pull-throughs of the sphincter, respiratory pressure changes and respiratory inversion points [RIP] are seen. HYPOTHESIS: The expiratory pressure profile will match the inspiratory pressure profile shifted by a coefficient whose magnitude can be estimated from the experimental data. METHODS: Manometric records were made of pull-throughs of the LES during quiet respiration in 11 anesthetized opossums. Pressure is a function of distance from the teeth [z]. Data at end-inspiration [Pi(z)] and endexpiration [P=(z)] were digitized. Pressures between the observed endinspiratory points were obtained by linear interpolation. The first model used was P,(z)=Pi(z+B1). A second model allowed pressure differences before and after the RIP; P,(z)=Pi(z+Bt) + B2 + Bgsrror function{(z-RIP)/B,}. RESULTS: The mean plus or minus the standard error of the B,‘s found for each animal by non-linear regression were 0.222kO.039 cm. The sum of squares deviation [SS] from the model was only 19% of the total SS of the observed points. Fitting the extra three constants only reduced the SS by an additional 8%. B,=0.202+0.036 cm. Calculation of Bt only from data proximal to the RIP yielded values (Bt= 0.216 +D.O42) in good agreement (r= .98) with the values of the second model. CONCLUSION: Most of the variations in the opossum LFS pressures with respiration are due to movement of the tonically contracted LES with respect to the catheter, not to phasic muscular contractions. APPLICATION: Since the major component of the human reflux barrier proximal to the RIP is thought to be from the LES, data from normal human volunteers proximal to the RIP was also analyzed by the last method. Here Bt was found as 0.206+.039 cm.
1239
ABSTRACTS
1994
IS DIABETIC GASTROPARESIS (DG) ASSOCIATED WITH VAGAL OR NONVAGAL AUTONOMIC NEUROPATHY? JS Rew ST Lee, RC Glena, JJ Hsu, WY Chey, CH Kim. Eof Medicine, University of Rochester, Rochester, NY. Vagal autonomic neuropathy has been implicated as a major pathogenetic mechanism of DG; however, the exact site of cholinergic dysfunction remains unknown. Aim: To determine whether or not cholinergic defect seen in DGis vagal or nonvagal. Methods: We studied 4 pts. with DG (mean age: 25.8 yrs) and 5 healthy controls (mean age: 37.8 yrs). Vagal and nonvagal cholinergic function were assessed by pancreatic polypeptide (PP) responses to insulin-induced hypoglycemia (Regular-Insulin, 3OmU/M’/min: J Clin Invest 61:781, 1978) and to bolus injection of secretin Q&kg: J Clin Endocrinol Metab 50:1094, 1980), respectively. PP was measured by radioimmunoassay. &&g: PP responses to secretin and insulin-induced hypoglycemia in DG were similar to the responses noted in the control group. However, the pattern of PP response in DG was highly variable (see Table).
Controls (n=5)
Cholinernic Vagal (+)
Diabetic Gastroparesis Case 1 Case 2 Case 3 Case 4
(+) (+) (-) (-)
(+) normal response
Inteerity Nonvaeal (+)
(+) (+) (+) (-)
(-) impaired response
Conclusions: Our results suggest that 1) DG is not necessarily associated with cholinergic dysfunction and 2) the cholinergic defect seen in DG is heterogeneous.
PACESETTER POTENTIAL CONDUCTION VELOCITY PREDICTS ROUX-EN-Y FUNCTIONAL ACTIVITY. sJDZ Chen, X. Yi, B. Schirmer. Depts. Liao -I UniInternal Medicine, and of Surgery versity of VA, Charlottesville, VA myoelectric Various abnormalities of activity are associated with the symptoms of We investigated which "ROUX limb syndrome." myoelectric parameters most closely correlated with the recovery of Roux limb funcRecordings tion from postoperative ileus. Roux limb patients undergoing of eight creation and intraoperative placement of bipolar seromuscular electrodes were obtained daily during the first week following surgery then weekly until one month postopThere were no significant diferatively. potential pacesetter ferences in the frequencies, amplitudes, or the percentage of pacesetter potentials with associated spike potentials when comparing tracings from postoperative day (POD) 1 to one month. velocity However, pacesetter conduction increased significantly from POD 1 to 7 (0.745.27 to 1.755.65 cm/set, p<.O5), and showed no significant increase thereafter to one month (2.02k.62 set). Conduction velocity correlated significantly with postoperative days 1 to 7 (r=.874, p=.OO4) and cliniConduction cal recovery of bowel function. velocity appears to be the most accurate parameter with which to measure recovery of Roux limb function from postoperative ileus, and may be an important parameter to measure in clther motility disorders.
OF
PAPERS
CYCLIC FREQUENCY VARIATIONS: A NEW CHARACTERISTIC OF GASTRIC MYOELECTRIC ACTIVITY. P. Zacchi Deutschbein, R. Kuhlbusch, P. Auer, H. J. Lfibke. P. Enck. H&rich Heine Hospitals, Dept. of University Gastmenterology, Dtlsseldorf, Germany. We previously demonstrated cyclic frequency changes of gastric myoelectric activity in newborns (J Gastrointest Mot 5, lQQ3:227), but no data exist on gastric frequency pattern in adults. It is well known that cyclic frequency variations occur in the heart, which are regulated by autonomic nervous system. Our aim was to verify the presence of gastric cyclic frequency variations in adults and to correlate them to variations of heart rate. METHODS. We studied 6 healthy female subjects (mean age 26 yrs, range 23-37 yrs). Electrogastrography was performed for 90 min before and 90 min after a solidlliouid meal. usina a oair of bioolar electrodes oositioned over the stomach. Data we~reconied onto a tape recorder for offline analysis of the frequency spectrum performed by a Fast Fourier Transformation. Minute-to- minute identification of the dominant frequency was performed. Median values for consecutive 5 minute intervals were calculated and plotted over the time to visually identifv cvclic variation and to calculate the variation coefficient of the dominant frequency. Conventional electrocardiogram was performed in all subjects in supine position. Beat-to-beat frequency variations were identified by a computerized electmcardiograph (ProSciCard System, MedySyst, Linden, Germany). and a variation coefficient was calculated. RESULTS.1) Gastric mean dominant frequency was 0.0437 + 0.005 Hz (mean + SD) preprandially and 0.0443 +,0.005 Hz during postprandial period. 2) A cyclic change of the gastnc dominant frequency was detected in 7/8 subjects during preprandial period and in 616 subjects postprandially; the cycle length was not significantly different between both periods (26.1 + 7.2 min and 24.19 + 10.27 min, respectively). 3) The variation coefficient of gastric cyclic activity was lower, but not significantly. before than after the meal (14.1 + 5.7% and 21.4 + 6.4%. respectively). 4) The variability of heart frequency and of gastric frequency of preprandial period was not significantly correlated (6.2 + 1 .Q% and 14.1 + 5.7% respectively; p>O.O5). CONCLUSION. Gastric electric activity in adults exhibits frequency variations which were, uptoday. never demonstrated. This cyclic activity is not disrupted by the meal. The wntml mechanisms of this activity might be related to those regulating heart rate variability. (Supported by a grant from Deutsche Forschungsgemeinschafl, EN 50/l 0).
DETERMINATION OF RESPIRATORY MOVEMENT OF THE ESOPHAGEAL SPHINCTER FROM MANDMETRIC DATA.
LOWER
J.A. Rinaldo Jr.. J.H. Steinbach. S. Zamani. G. GosseQ, A. Babaknia. N. Izima. M. Barn University of California and VA Medical Center, San Diego, California and Providence Hospital, Southfield, Michigan. In the opossum, all of the lower esophageal sphincter [LES] is in the abdominal cavity. However, during pull-throughs of the sphincter, respiratory pressure changes and respiratory inversion points [RIP] are seen. HYPOTHESIS: The expiratory pressure profile will match the inspiratory pressure profile shifted by a coefficient whose magnitude can be estimated from the experimental data. METHODS: Manometric records were made of pull-throughs of the LES during quiet respiration in 11 anesthetized opossums. Pressure is a function of distance from the teeth [z]. Data at end-inspiration [Pi(z)] and endexpiration [P=(z)] were digitized. Pressures between the observed endinspiratory points were obtained by linear interpolation. The first model used was P,(z)=Pi(z+B1). A second model allowed pressure differences before and after the RIP; P,(z)=Pi(z+Bt) + B2 + Bgsrror function{(z-RIP)/B,}. RESULTS: The mean plus or minus the standard error of the B,‘s found for each animal by non-linear regression were 0.222kO.039 cm. The sum of squares deviation [SS] from the model was only 19% of the total SS of the observed points. Fitting the extra three constants only reduced the SS by an additional 8%. B,=0.202+0.036 cm. Calculation of Bt only from data proximal to the RIP yielded values (Bt= 0.216 +D.O42) in good agreement (r= .98) with the values of the second model. CONCLUSION: Most of the variations in the opossum LFS pressures with respiration are due to movement of the tonically contracted LES with respect to the catheter, not to phasic muscular contractions. APPLICATION: Since the major component of the human reflux barrier proximal to the RIP is thought to be from the LES, data from normal human volunteers proximal to the RIP was also analyzed by the last method. Here Bt was found as 0.206+.039 cm.
1239