Electrogastrography: Poor correlation with antro-duodenal manometry and doubtful clinical usefulness in adults

Table 1 Electrogastrography (EGG) and antroduodenal manometry (ADM) variables

1 EGG variables
	(1) Preprandial (fasting) and postprandial percentage of time with dominant frequency in:
	Bradygastria (0.5-2 cycles per minute)
	Normogastria (2-4 cycles per minute) (0.5-2 cycles per minute)
	Tachygastria (4-10 cycles per minute)
	(2) Pre- and postprandial power attributed to the three frequency bands (bradygastria, tachygastria and normogastria)
	(3) Pre- and postprandial dominant power instability co-efficient (DPIC)
	(4) Pre- and postprandial dominant frequency instability co-efficient (DFIC)
	(5) Pre- and postprandial dominant frequency (DF)
	(6) Pre and postprandial period dominant power (PDP)
	(7) Power ratio (ratio of postprandial to preprandial power of dominant frequency)
2 ADM variables
	(1) Pre- and postprandial motility index (MI)
	(2) Pre- and postprandial contractile frequency
	(3) Pre- and postprandial median amplitude
	(4) MI ratio (ratio between postprandial and preprandial motility index)
	(5) Amplitude ratio (ratio between postprandial and preprandial amplitude)

Table 2 Correlation matrix (r-values) for parameters from antroduodenal manometery and electrogastrography (n = 144)

Parameters	Pre MI1	Post MI1	MI ratio§	Pre Freq	Post Freq	Pre Amp1	Post Amp1	Amp Ratio1
Pre-Brady power1	0.15	0.01	-0.10	0.10	0.01	0.08	0.06	-0.01
Pre-Normo power1	0.06	0.03	-0.01	0.10	0.05	-0.01	-0.01	0.00
Pre-Tachy power1	0.10	0.05	-0.03	0.13	0.07	0.01	0.00	-0.01
Pre-Brady DF%	0.06	-0.01	-0.05	0.05	0.01	-0.09	0.08	0.12
Pre-Normo DF%	0.05	0.09	0.06	0.08	0.08	0.06	0.14	0.06
Pre-Tachy DF%	-0.03	-0.13	-0.11	-0.07	-0.12	-0.02	-0.18a	-0.11
Pre-DFIC	-0.04	0.04	0.06	-0.12	0.02	0.07	0.03	-0.04
Pre-DPIC	-0.01	-0.13	-0.12	-0.12	-0.13	0.09	-0.10	-0.14
Pre-DF	-0.08	-0.11	-0.05	-0.10	-0.10	-0.04	-0.17a	-0.09
Pre-PDP1	-0.09	0.01	0.08	0.00	0.03	-0.02	-0.04	-0.02
Post-Brady power1	0.04	-0.04	-0.07	0.13	-0.04	-0.10	0.02	0.09
Post-Normo power1	0.09	-0.01	-0.07	0.13	0.04	-0.03	-0.04	-0.01
Post-Tachy power1	0.08	0.01	-0.05	0.15	0.03	-0.06	-0.02	0.03
Post-Brady DF%	0.00	0.01	0.01	-0.02	-0.07	-0.06	0.01	0.05
Post-Normo DF%	-0.03	-0.03	-0.01	-0.06	-0.04	0.06	0.06	0.00
Post-Tachy DF%	0.02	-0.04	-0.05	0.05	-0.02	-0.05	-0.09	-0.02
Post-DFIC	0.04	0.03	-0.01	0.11	0.08	-0.09	-0.11	-0.01
Post-DPIC	-0.06	-0.1a	-0.14	-0.09	-0.17a	0.02	-0.18a	-0.15
Post-DF	0.04	-0.01	-0.04	0.06	0.00	-0.05	0.00	0.04
Post-PDP1	0.06	-0.01	-0.04	0.08	0.04	0.01	-0.02	-0.03
Power ratio1	0.04	-0.04	-0.07	0.04	-0.01	-0.02	-0.04	-0.01

¹Log values,

^aP < 0.05.

Table 3 Electrogastrography parameters among various diagnostic groups

EGG parameter	Chronic intestinal pseudo-obstruction (n = 11)	Enteric dysmotility(n = 22)	Irritable bowel syndrome(n = 52)	Functional dyspepsia/gastroparesis (n = 13)	Slow transit constipation(n = 26)
Preprandial
Log Brady power	2.9 ± 0.4	2.8 ± 0.5	2.7 ± 0.5	2.7 ± 0.4	2.6 ± 0.4
Log Normo power	3.8 ± 0.5a	3.7 ± 0.5	3.6 ± 0.5	3.6 ± 0.5	3.5 ± 0.5
Log Tachy power	3.7 ± 0.4a	3.5 ± 0.5	3.3 ± 0.4	3.4 ± 0.4	3.3 ± 0.4
Brady DF%	2.7 (0-16.2)	1.8 (0-17.5)	0 (0-15.2)	0 (0-10.3)	2 (0-14.3)
Normo DF%	89.7 (0-100)	88.2 (36.2-100)	92.0 (38.6-100)	89.8 (59-100)	87.7 (30.8-100)
Tachy DF%	6.0 (0-100)	8.8 (0-61.7)	5.1 (0-61.4)	6.5 (0-73.7)	6.1 (0-69.2)
DFIC	22 (3-51)	32 (5-68)	23 (3-75)a	31 (1-70)	30 (3-69)
DPIC	77 (40-165)	67 (33-169)	64 (39-145)	65 (31-101)	60 (47-159)
DF	3.05 (2.58-11.25)	3.05 (2.34-3.98)	3.05 (2.11-6.05)	3.05 (2.58-3.75)	3.05 (2.11-8.91)
Log PDP	2.4 ± 0.6a	2.0 ± 0.5	2.1 ± 0.6	2.1 ± 0.5	1.9 ± 0.5
Postprandial
Log Brady power	3.0 ± 0.4	3.0 ± 0.5	2.9 ± 0.4	2.9 ± 0.5	2.8±0.5
Log Normo power	4.1 ± 0.3	4.1 ± 0.5	4.0 ± 0.5	4.1 ± 0.7	3.7 ± 0.5b
Log Tachy power	3.9 ± 0.4	3.8 ± 0.5a	3.6 ± 0.4	3.8 ± 0.6	3.5 ± 0.4a
Brady DF%	0 (0-5.8)	0 (0-5.0)	0 (0-14.5)	0 (0-17.1)	1.8 (0-20)b
Normo DF%	92.3 (0-100)	96.1 (32.1-100)	96.5 (62.5-100)a	95.5 (32-100)	87.2 (56.5-100)d
Tachy DF%	5.8 (0-100)	1.8 (0-66)	3.1 (0-18.8)	1.9 (0-21.1)	9.3 (0-33)b
DFIC	18 (4-63)	16 (2-62)	15 (3-77)a	27 (5-56)	27 (8-72)b
DPIC	67 (59-81)	56 (35-110)	70 (34-129)	61 (30-82)	64 (39-108)
DF	3.05 (2.58-9.14)	3.28 (2.34-9.61)	3.05 (2.58-3.75)	3.28 (2.11-10.08)	3.05 (2.34-3.75)
Log PDP	2.5 ± 0.5	2.5 ± 0.5	2.4 ± 0.5	2.5 ± 0.8	2.1 ± 0.6b
Log Power ratio	0.2 ± 0.5	0.5 ± 0.4	0.4 ± 0.4	0.5 ± 0.6	0.2 ± 0.5