Estudo da variabilidade da frequência cardíaca e medidas hemodinâmicas em crianças e adolescentes com sintomas do trato urinário inferior

Abstract

The lower urinary tract dysfunction (LUTD) is a broad term that describes the full spectrum of functional changes in any of the stages of micturition (filling or emptying). This term encompasses different symptoms and conditions such as urinary incontinence, enuresis and overactive bladder (OAB). The autonomous nervous system (ANS) participates in the control of the lower urinary tract and digestive system, any alteration of the ANS may cause dysfunctions of both organ systems. The aim of the study is to analyze and compare the pattern of changes amongst heart rate variability (HRV) and hemodynamic measurements in children and adolescents with and without LUTD. The cases were composed of 32 subjects (22 female and 10 male) and the control group of 29 subjects (15 male and 14 female) (p= 0.10). The evaluation included body mass index (BMI), DVSS (Disfunctional Voiding Scoring System, SDQ (strengths and difficulties questionnaire), SDSC (the sleep disturbance scale for children), Rome IV criteria and a questionnaire about physical activity, ultrasound, uroflowmetry with electromyography. The study of the SNA was performed with a Finometer during rest, during deep respiration (parasympathetic stress) and during orthostatic position (predominant sympathetic stress). During rest, a smaller interval RR was found 740ms vs. 796ms, (p=0.014) within the cases of overactive bladder (OAB). Under deep respiration the same was observed within cases of LUTS 756ms vs. 825ms, (p=0.049), OAB 760ms vs. 825ms, (p=0.037) and enuresis (719ms vs. 825ms (p=0.036). SDNN under deep respiration was 50.3ms vs. 60.6ms, (p=0.052) for OAB cases and 74.1ms vs. 103.4ms (p=0.009) for cases of enuresis. The total power (TP) under the same condition was 5880 ms2 vs. 9443 ms2 (p=0.054) for OAB and 5401 ms2 vs. 9443 ms2 (p=0.023) for cases of enuresis. The hemodynamic measurements during rest for LUTS cases were: stroke volume 36.5ml vs. 50.8ml (p=0.050) and cardiac output (2.86 ml/s vs. 3.93ml/s, (p=0.034). For OAB cases, stroke volume 39.2 ml vs. 50.8 ml (p=0.046) and for Enuresis cases, stroke volume 39.3ml vs. 50.8 ml (p=0.030) and cardiac output (2.91ml/s vs. 3.93ml/s (p=0.036). The present study evaluated HRV as well as hemodynamic measurements and was able to point out that lower parasympathetic responses and higher sympathetic responses were found specially within cases of enuresis, which is compatible with recent studies. Hypoactivity of the parasympathetic system and faster response of the sympathetic system was seen within the case group, especially within cases of enuresis and overactive bladder. Our results showed that there are differences in HRV and hemodynamics measurements in children and adolescents with LUTS, especially those with enuresis and OAB.