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

Abstract

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. Three monopolar silver-silver chloride electrodes were sutured to the anterior liver surface under anaesthesia. A recording session of 60 min was performed daily for 10 days. The effect of temporary clamping of the hepatic artery and portal vein, and of liver insult by irradiation, on the hepatic electric activity was also studied. Electric waves were recorded from the three electrodes. They were monophasic with a positive deflection, had identical frequency and amplitude from the three electrodes, and were reproducible when the test was repeated in the same animal. The mean frequency was 10.6 +/- 1.8 cycles/s and amplitude 63.7 +/- 11.4 microV. Fast activity spikes and abnormal waves were not encountered. Temporary occlusion of the hepatic artery and portal vein produced irregularities in the wave frequency and amplitude; the wave dysrhythmia disappeared after clamp release. The EHG following liver insult by irradiation exhibited two patterns: silent and dysrhythmic. A normal EHG could be characterized in the canine model. A dysrhythmic pattern was produced when liver vessels were clamped and following liver 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.