The aim of the study is to evaluate changes in autonomic nervous system following treatment with anticholinergic medication for OAB symptoms.

Heart variability as a measure of the functioning of the autonomic nervous system will be recorded before and three months following treatment with solifenacin succinate 10 mg daily.

30 women with clinical diagnosis of overactive bladder will be recruited for the study. An ECG strip for fifteen minutes at rest will be recorded through a 12-bit analog/digital data acquisition card (National Instruments, Austin TX) with a sampling frequency of 200 Hz and stored in a computer for offline studies. The digitized ECG signals will than processed and analyzed via dedicated robust software to detect the R wave peaks. The R point of each QRS complex was defined and the interval between two consecutive R points (the R-R interval) was computed. All R-R intervals will be visually inspected and manually edited if necessary to exclude background noise and artifacts. The edited segments accounts for less than 1% in each patient. A "clean" 2-5-min segment (preferably unedited) will be used for the analyses. An autoregressive model with the order of 16 was will be used to estimate the power spectrum densities of HRV. The power spectra are quantified by measuring the area under the following frequency bands: low-frequency (LF) (0.04-0.15 Hz) known to represents sympathetic activity, and high-frequency (HF) (0.15-0.4 Hz) which represents parasympathetic activity.

Inclusion Criteria:

Clinical diagnosis of OAB

Exclusion Criteria:

1) stress urinary incontinence and voiding symptoms, 2) pregnancy, 3) pathological conditions that can interfere with the ANS, (e.g. coronary heart disease, heart failure, or other cardiac conditions, hypertension, neurological diseases or diabetes , 4) medications that can interfere with the ANS, including beta-receptor agonists or antagonists, antiarrhythmic agents or antihypertensive drugs, anticholinergic agents or adrenergic alpha-antagonists, tricyclic or serotoninergic antidepressants.

Patients were diagnosed as having OAB syndrome by an urogynecologist based on their clinical symptoms (urinary urgency, with or without urinary urgency incontinence, urinary frequency or nocturia).