Electropotential and Pressure Variations in the Normal Human Urinary Bladder

Abstract

From a study of synchronous electropotential and pressure curves secured from individuals with normal bladder function it was apparent that a remarkable similarity in form was present. The 1st change in pressure was in each case a diminution approx. coincident with the initial, or "A" deflection of the electromyogram. A more sustained rise in pressure followed, closely corresponding with the "B" deflection of the electropotential record. Both oscillo-graphic tracings then returned to their base-lines. Shifts in potential always preceded alterations in pressure by an avg. of 0.66 sec. This interval was prolonged in the neurogenic bladder of the paraplegic patient to as much as 2.6 sec. (avg., 1.12 sec.) On occasion, entirely typical, spontaneous potential changes took place in all subjects when no significant alteration in intra-vesical pressure could be detected. Conversely, pressure changes might be evoked without alteration of potential in the vesicle musculature. These observations were interpreted as an indication that potential and pressure changes in the bladder are not invariably interrelated in a quantitative manner, although the potential shifts, as recorded, were indeed reflections of muscular activity of the bladder and not the product of electrode movement or other artifact.