The electrovaginogram: study of the vaginal electric activity and its role in the sexual act and disorders

We investigated the hypothesis that the vagina generates electric waves which effect vaginal contraction during penile thrusting.

In 24 healthy female volunteers, the electric waves of the vagina were recorded by two electrodes applied to its wall. The vaginal pressure was registered by a manometric tube. The electric waves and vaginal pressure were recorded at rest and on vaginal distension by condom in increments of 10 ml of carbon dioxide. The test was repeated after vaginal anesthetization proximally and distally to the electrodes.

Slow waves (SWs) were recorded from the two electrodes with regular rhythm and similar frequency, amplitude and conduction velocity. They were randomly followed or superimposed by action potentials (APs). Vaginal pressure increase was coupled with APs. Large-volume condom distension significantly increased the electric waves’ variables and pressure. Upon vaginal anesthetization, the electric waves were recorded proximal but not distal to the anesthetized area.

Electric waves could be recorded from the vagina. They spread caudad. A pacemaker was postulated to exist at the upper vagina evoking these waves. The electric waves seem to be responsible for the vaginal contractile activity. Large-volume vaginal distension effected an increase in the vaginal electric waves and pressure which probably denotes increased vaginal muscle contraction. It appears that penile thrusting during coitus stimulates the vaginal pacemaker which effects an increase in vaginal electric activity and muscle contractility and thus leading to an increase in sexual arousal. The vaginal pacemaker seems to represent the G spot, which is claimed to be a small area of erotic sensitivity in the vagina. The electrovaginogram may act as a diagnostic tool in the investigation of sexual disorders.