Urgency degree and bladder contraction velocity: sequential changes in women with idiopathic detrusor overactivity

In patients with idiopathic detrusor overactivity (DO) who showed storage symptoms worsening with time, we checked whether and which urodynamic parameter changes are associated with an increased urgency degree.

We analyzed retrospectively the urodynamic findings in 54 women -27 with storage symptoms (Group A, mean age 32 +/- 7 years) and 27 controls (Group B, mean age 30 +/- 9 years). These latter had a history of recurrent UTIs (urinary tract infections), but when seen by us had no UTI, DO, lower urinary tract symptoms, or any other pathological finding. Group A had a first urodynamic examination when first referred (time 1) and were re-assessed a mean of 16 months later (time 2) for worsened storage symptoms.

In Group A, an idiopathic DO was shown at both times 1 and 2; urgency of voiding could be delayed during cystometry for >or=2 min (= moderate urgency) at time 1 and for <2 min (= severe urgency) at time 2; detrusor contraction strength or contractility proved higher than in Group B (P < 0.001) and increased from time 1 to time 2 (P < 0.001), detrusor shortening velocity being always the major component of the higher contractility levels.

A DO-related increase in bladder contractility may have been further enhanced by severe urgency through a positive feedback mechanism. The urgency degree proved closely associated in DO patients with the level of detrusor shortening velocity rather than with detrusor pressure.