Study of the electric activity of the liver with identification of a normal 'electrohepatogram' in a canine model

Objective The electric activity of the liver was studied in 14 mongrel dogs , aiming at characterizing a normal electrohepatogram (EHG) that might act as a standard for abnormal recordings in hepatic pathological conditions. Methods Three monopolar silver-sliver chloride electrodes were sutured to t he anterior liver surface under anaesthesia. A recording session of 60 min was performed daily for 10 days. The effect of temporary clamping of the he patic artery and portal vein, and of liver insult by irradiation, on the he patic electric activity was also studied. Results Electric waves were recorded from the three electrodes. They were m onophasic with a positive deflection, had identical frequency and amplitude from the three electrodes, and were reproducible when the test was repeate d in the same animal. The mean frequency was 10.6 +/- 1.8 cycles/s and ampl itude 63.7 +/- 11.4 mu V. Fast activity spikes and abnormal waves were not encountered. Temporary occlusion of the hepatic artery and portal vein prod uced irregularities in the wave frequency and amplitude; the wave dysrhythm ia disappeared after clamp release. The EHG following liver insult by irrad iation exhibited two patterns: silent and dysrhythmic. Conclusion A normal EHG could be characterized in the canine model. A dysrh ythmic pattern was produced when liver vessels were clamped and following l iver injury. It is suggested that in liver diseases, the normal EHG pattern is deranged and might thus act as a diagnostic tool in such conditions. Eu r J Gastroenterol Hepatol 11:1239-1243 (C) 1999 Lippincott Williams & Wilki ns.