Electroanatomical Mapping of the Urinary Bladder

Abstract

A noncontact mapping system (EnSite) was used for electroanatomical mapping of the bladder simultaneously with pressure flow study in three women with lower urinary tract symptoms. We selected the periods of obvious detrusor activity. Data were processed to remove baseline drift, and an envelope of electrovesicography (EVG) data was created. The correlation coefficient for the correlation between between the EVG envelope and the detrusor pressure (Pdet) was calculated. Bladder geometry was successfully created in all 3 patients. Simultaneous recording of EVG and pressure flow data was successful in 1 patient. Scatter plots were made of the highest correlation coefficient, showing a positive correlation between the Pdet and the envelope, and negative correlation between abdominal pressure (Pabd) and the envelope. Minimal electrical activity could be observed. Significant weak to moderate correlation coefficients were found for the correlations between Pdet and EVG and between Pabd and EVG.

Cardiac electrophysiology catheters for electrophysiological assessments of the lower urinary tract—A proof of concept ex vivo study in viable ureters

“…In this work we use cardiac electrophysiology catheters and needle electrodes to provide quantitative values regarding propagation velocities, pacing threshold, activation patterns, and refractory time in the ureteric smooth muscle. Our study extends the results of two previous studies which provided qualitative insight on the use of commercially available cardiac electrophysiology equipment for detecting electrical activity in the urinary smooth muscle (bladder). To the best knowledge of the authors, the present work is the first in the lower urinary tract to: i) provide quantitative measurements of propagating electrical activity by means of catheter‐based electrodes, in a well‐defined ex vivo stimulation protocol; and ii) compare those recordings with conventional needle electrodes.…”

“…Since needle electrodes always had contact with the tissue, the latter point would mainly involve the cardiac catheters, where it is more difficult to assess the contact between electrode and tissue. Contactless recordings were shown in the urinary tract by Frag et al, however the amplitude of the signals may be different between contact and contactless recordings (most probably lower amplitudes are associated with contactless recordings) and may justify our unsuccessful recordings using cardiac catheters. Catheter design could be optimized to improve electrode‐tissue contact (e.g., catheters with inflatable balloon).…”

“…To the best of our knowledge, only two very recent studies have attempted the measurement of electrophysiological signals in the lower urinary tract using cardiac catheters. These investigations were done directly in vivo in urinary bladders of volunteers.…”

Underactive bladder in aging rats is associated with a reduced number of serotonin‐expressing cells in the urethra and is improved by serotonin application to the urethra

“…However, a recent study showed a good correlation between pressure flow studies and BVE in women . Moreover, a BVE <60% is commonly used to define DU . Therefore, we believe that the BVE of 48% in the aged female rats used in this study is a robust indicator of DU.…”

“…17 Moreover, a BVE <60% is commonly used to define DU. 18 Therefore, we believe that the BVE of 48% in the aged female rats used in this study is a robust indicator of DU.…”