Detrusor after-contraction on ambulatory urodynamics in symptomatic women.

Objectives
To investigate the association between detrusor after-contraction and urodynamic parameters in a cohort of patients undergoing urodynamic studies by ambulatory monitoring.

Methods
All symptomatic adult female patients with non-neurogenic lower urinary tract dysfunction having ambulatory monitoring over the period January 1998 to January 2014 were included. Urodynamic traces were reviewed to identify detrusor after-contraction. Measured urodynamic variables were Qmax (mL/s), Vvoid (mL) and Pdet.Qmax (cmH2O). Student's unpaired t-test was used to compare the mean of the variable in the detrusor after-contraction and non-detrusor after-contraction groups.

Results
We identified 331 women with a median age of 50 years (range 16–82). Detrusor after-contraction was seen after at least one void in 122 patients giving a prevalence of 37%. A total of 167 (51%) patients had detrusor overactivity. Diagnosis of detrusor overactivity was associated with the presence of detrusor after-contraction (P < 0.05). Overall, patients with detrusor after-contraction had a statistically higher mean Pdet.Qmax (32 vs 28 cmH2O, P = 0.04) and lower mean voided volume (300 vs 378 mL, P < 0.001).

Conclusion
These findings suggest a relatively high prevalence of detrusor after-contraction during ambulatory monitoring, and an association between detrusor overactivity, Vvoid, Pdet.Qmax and detrusor after-contraction recorded during ambulatory monitoring. Therefore, a link between detrusor after-contractions and the syndrome of overactive bladder can be postulated.