Department of Surgery/Division of Urology, VCU Medical Center, West Hospital, Virginia Commonwealth University School of Medicine, 7th Floor, Room 7205, 1200 East Broad Street, PO Box 980118, Richmond, VA, 23298-0118, USA.
Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University School of Engineering, Richmond, VA, USA.
World J Urol. 2017 Aug;35(8):1255-1260. doi: 10.1007/s00345-016-1994-0. Epub 2016 Dec 26.
Low amplitude rhythmic contractions (LARC) occur in detrusor smooth muscle and may play a role in storage disorders such as overactive bladder and detrusor overactivity. The purpose of this study was to determine whether LARC frequencies identified in vitro from strips of human urinary bladder tissue correlate with in vivo LARC frequencies, visualized as phasic intravesical pressure (p ) waves during urodynamics (UD).
After IRB approval, fresh strips of human urinary bladder were obtained from patients. LARC was recorded with tissue strips at low tension (<2 g) and analyzed by fast Fourier transform (FFT) to identify LARC signal frequencies. Blinded UD tracings were retrospectively reviewed for signs of LARC on the p tracing during filling and were analyzed via FFT.
Distinct LARC frequencies were identified in 100% of tissue strips (n = 9) obtained with a mean frequency of 1.97 ± 0.47 cycles/min (33 ± 8 mHz). Out of 100 consecutive UD studies reviewed, 35 visually displayed phasic p waves. In 12/35 (34%), real p signals were present that were independent of abdominal activity. Average UD LARC frequency was 2.34 ± 0.36 cycles/min (39 ± 6 mHz) which was similar to tissue LARC frequencies (p = 0.50). A majority (83%) of the UD cohort with LARC signals also demonstrated detrusor overactivity.
During UD, a subset of patients displayed phasic p waves with a distinct rhythmic frequency similar to the in vitro LARC frequency quantified in human urinary bladder tissue strips. Further refinements of this technique may help identify subsets of individuals with LARC-mediated storage disorders.
低振幅节律性收缩（LARC）发生在逼尿肌平滑肌中，可能在储存障碍中起作用，如膀胱过度活动症和逼尿肌过度活动。本研究的目的是确定从人膀胱组织条带体外鉴定的 LARC 频率是否与尿动力学（UD）期间作为相发性膀胱内压（p）波可视化的体内 LARC 频率相关。
在 IRB 批准后，从患者中获得新鲜的人膀胱组织条带。在低张力（<2g）下记录 LARC，并通过快速傅里叶变换（FFT）进行分析，以确定 LARC 信号频率。回顾性地审查 UD 描记图中充盈时 p 描记图上 LARC 的迹象，并通过 FFT 进行分析。
用 9 个组织条带（n=9）以 1.97±0.47 个/分钟（33±8mHz）的平均频率鉴定出明显的 LARC 频率。在 100 次连续 UD 研究中，35 次显示出相发性 p 波。在 12/35（34%）中，存在与腹部活动无关的真实 p 信号。平均 UD LARC 频率为 2.34±0.36 个/分钟（39±6mHz），与组织 LARC 频率相似（p=0.50）。具有 LARC 信号的 UD 队列的大多数（83%）也表现出逼尿肌过度活动。
在 UD 期间，一部分患者显示出具有相似的节律性频率的相发性 p 波，类似于体外定量的人膀胱组织条带中的 LARC 频率。这种技术的进一步改进可能有助于识别具有 LARC 介导的储存障碍的亚组个体。
