Transcutaneous Electrorectography: Human Electrorectogram from Surface Electrodes

Shafik, Ahmed; Nour, Ashraf; Fattah, Alia Abdel

doi:10.1159/000201279

Cited by 23 publications

(24 citation statements)

References 6 publications

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“…Smooth muscle EMG is in the low frequency range. Also the rectum possesses such activity and an electrorectogram could be recorded intrarectally and percutaneously (Shafik, 1993b(Shafik, , 1994Shafik et al, 1995) (Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

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Transmission of Rectal Electric Waves: Is it through Circular or Longitudinal Smooth Muscle Layers or Both?

Shafik

El-Sibai

2001

Archives of Physiology and Biochemistry

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The rectum possesses electric activity in the form of pacesetter (PPs) and action potentials (APs). In recent studies we suggested that the waves are not initiated by the extrarectal autonomic innervation but might be triggered by a 'rectosigmoid pacemaker' and are transmitted in the rectal wall through the rectal musculature and not the enteric nerve plexus. To investigate whether the rectal waves are transmitted through the circular or longitudinal muscle layer, the rectum of 18 mongrel dogs was exposed under anesthesia through an abdominal incision. Three electrodes were applied to the rectal wall (longitudinal muscle layer) and another 3 electrodes to the circular muscle; the latter was exposed by splitting apart the fibers of the longitudinal muscle. Rectal electric activity and pressure were recorded from the 6 electrodes before and after performing individual myotomy of the rectal longitudinal (9 dogs), circular (9 dogs), and then the whole muscle layers (18 dogs). The myotomy was performed proximal to and between the electrodes. Pacesetter (PPs) and action potentials (APs) were recorded from the 3 electrodes on the longitudinal muscle but no waves were registered from those on the circular muscle. After longitudinal muscle myotomy was performed between electrodes 1 and 2, PPs and APs were recorded from electrode 1 but not 2 and 3 and when performed proximally to electrode 1, no waves were registered. The rectal pressure increased concomitantly with occurrence of APs. Circular muscle myotomy effected no change in the rectal electric activity recorded from the 3 electrodes applied to the longitudinal muscle. In total muscle myotomy, the electric waves were recorded from the electrodes proximal but not distal to the myotomy. We propose that the motile activity of the rectal longitudinal muscle is initiated by the electric activity which appears to be triggered by the rectosigmoid pacemaker, while that of the circular muscle fibers is believed to be initiated by the stretch reflex induced by rectal distension. This concept is evidenced not only by the current findings but also by the histologic structure of the rectal musculature being of the unitary type of smooth muscles.

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Section: Introductionmentioning

confidence: 99%

“…Electrorectogram of a normal subject showing pacesetter and action potentials (fromShafik et al, 1995).…”

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confidence: 99%

Transmission of Rectal Electric Waves: Is it through Circular or Longitudinal Smooth Muscle Layers or Both?

Shafik

El-Sibai

2001

Archives of Physiology and Biochemistry

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“…1). The PPs have a regular rhythm with a mean Ϯ SD frequency of 2.6 Ϯ 0.4 cycles/min (range, 2-4), amplitude of 1.9 Ϯ 0.6 mV (range, 1-3), and velocity of conduction of 4.2 Ϯ 0.9 cm/s (range, [3][4][5][6]. The waves were triphasic with a small positive, large negative, and another small positive deflection [4 -6] (Fig.…”

Section: Introductionmentioning

confidence: 99%

Rectal Pacing: Pacing Parameters Required for Rectal Evacuation of Normal and Constipated Subjects

Shafik¹,

El-Sibai²

2000

Journal of Surgical Research

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“…It manifested as slow waves or pacesetter potentials (PPs) which may be followed by fast activity spikes or action potentials. The waves were recorded either transluminally or percutaneously (4,17,18,22). The electrogram exhibited wave abnormalities in disorders of the aforementioned organs (4,5,11,12,15,16,23,24).…”

Section: Introductionmentioning

confidence: 99%

Transcutaneous electrohepatogram in humans

Shafik

1999

Front Biosci

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We could recently characterize a normal "electrohepatogram" (EHG) in a canine model. It consisted of monophasic positively deflected slow waves or pacesetter potentials (PPs). A "dysrhythmic EHG" was produced when the liver was insulted by hepatic vessel clamping or liver irradiation.The postulation that electrohepatography might act as an investigative tool in liver diseases prompted the author to develop the EHG percutaneously in humans. 23 healthy volunteers (16 men, 7 women; mean age 38.6 years) and 13 patients (8 men, 5 women; mean age 34.2 years) with huge supraumbilical ventral hernia were studied. The liver was exposed during the ventral hernia repair and 3 electrodes were sutured to the liver capsule. The optimal position for percutaneous recording was identified. The 3 electrodes were placed, 5 cm apart, on a transverse line, parallel to and 1.5-2 cm below, the costal margin. PPs were recorded from the 3 electrodes applied directly to the liver and from those applied to the skin. The wave was monophasic and positively deflected with a mean frequency of 8.3 cycle/s and amplitude of 56.5 µV. The PPs had the same frequency and amplitude from the 3 electrodes applied to the same subject. The percutaneously recorded waves were identical with those recorded directly from the liver. A percutaneous EHG could be characterized for the normal liver in humans. It might show changes in liver diseases and thus act as an investigative tool in the diagnosis of such conditions.

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Transcutaneous Electrorectography: Human Electrorectogram from Surface Electrodes

Cited by 23 publications

References 6 publications

Transmission of Rectal Electric Waves: Is it through Circular or Longitudinal Smooth Muscle Layers or Both?

Transmission of Rectal Electric Waves: Is it through Circular or Longitudinal Smooth Muscle Layers or Both?

Rectal Pacing: Pacing Parameters Required for Rectal Evacuation of Normal and Constipated Subjects

Transcutaneous electrohepatogram in humans

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