The electrovesicogram in the overactive bladder: role in determining pathogenesis and diagnostic significance.

We investigated the hypothesis that the abnormal contractility of the smooth musculature of the overactive bladder (OAB) may be due to derangement of its electrical activity. Percutaneous electrovesicography was performed in 22 patients (mean age 46.3 years, 12 men, ten women) with OAB and 14 healthy volunteers (mean age 45.6 years, eight men, six women). Recording was performed with the bladder full and empty. Three electrodes were applied suprapubically and one reference electrode was applied to a lower limb. Reproducible regular triphasic slow waves (SWs) were recorded in the volunteers. The pattern of the full and empty bladder were similar except for the higher amplitude of the waves in the former (P < 0.05). The OAB patients showed a "dysrhythmic" pattern with irregular frequency, amplitude and conduction velocity in both the empty and full bladders. We obtained tachyrhythmic, bradyrhythmic and arrhythmic areas in the same recording. The OAB exhibited a "dysrhythmic" electrical pattern with areas of different electrical activity in the same recording. The tachyrhythmic, bradyrhythmic and arrhythmic areas are suggested to explain the abnormal vesical contractions and clinical manifestations of OAB. Further studies are required to investigate the cause of the dysrhythmic pattern and the electrovesicogram is suggested as an investigative tool in OAB diagnosis.