A new and automated method for objective analysis of detrusor rhythm during the filling phase

Klausner, Adam P.; King, Ashley; Byrne, Michael D.; Habibi, Joseph; Li, Kai; Sabarwal, Vikram; Speich, John E.; Ratz, Paul H.

doi:10.1007/s00345-013-1084-5

Cited by 2 publications

(3 citation statements)

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“…; Klausner et al. ). If SRC and QS‐induced myogenic contraction are due to a common population of actomyosin crossbridges and are regulated by a common mechanism, then QS is a potential mechanical probe to study SRC regulation and its alteration in overactive bladder.…”

Section: Discussionmentioning

confidence: 97%

“…Elevated levels of RC have been shown in patients with overactive bladder disorder (Kinder and Mundy 1987 ; Drake et al 2005 ); however, a pathological link between RC and overactive bladder has not been determined. Furthermore, SRC in human and rabbit bladder often has an inconsistent amplitude and/or frequency (Sibley 1984 ; Byrne et al 2013 ) and requires complex analysis to quantify (Byrne et al 2013 ; Klausner et al 2013 ). If SRC and QS-induced myogenic contraction are due to a common population of actomyosin crossbridges and are regulated by a common mechanism, then QS is a potential mechanical probe to study SRC regulation and its alteration in overactive bladder.…”

Section: Discussionmentioning

confidence: 99%

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Evidence for a common mechanism for spontaneous rhythmic contraction and myogenic contraction induced by quick stretch in detrusor smooth muscle

et al. 2013

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Detrusor smooth muscle exhibits myogenic contraction in response to a quick stretch (QS) as well as spontaneous rhythmic contraction (SRC); however, whether the same population of actomyosin crossbridges with a common regulatory mechanism is responsible for these two types of contraction has not been determined. Detrusor strips from New Zealand white rabbit bladders were allowed to develop SRC at a reference muscle length (Lref), or rhythmic contraction (RC) was induced with tetraethylammonium (TEA). Multiple 10-msec stretches of 15% Lref were then imposed at Lref randomly during the rhythm cycle, and the nadir-to-peak (NTP) tension amplitude of the resulting myogenic contraction was measured. The amplitude and period of the rhythm cycle were measured prior to each QS. NTP was larger when a QS was imposed during a portion the cycle when tension was smaller (n = 3 each SRC and TEA-induced RC). These data suggest that when the rhythmic mechanism was mostly inactive and tension was near a minimum, a larger portion of a shared population of crossbridges was available to produce a myogenic response to a QS. Rho kinase, cyclooxygenase-1, and cyclooxygenase-2 inhibitors (H-1152, SC-560, and NS-398) affected SRC amplitude and NTP amplitude following a QS to the same degree (n = 3 each drug), providing additional evidence to support the hypothesis that a common mechanism is responsible for SRC and myogenic contraction due to QS. If a common mechanism exists, then QS is a potential mechanical probe to study SRC regulation and its alteration in overactive bladder.

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Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Evidence for a common mechanism for spontaneous rhythmic contraction and myogenic contraction induced by quick stretch in detrusor smooth muscle

et al. 2013

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“…Several previous studies have used FFT and other methods to quantify LARC in preclinical animal models. [ 2 , 3 , 7 , 11 , 16 – 21 ] Streng et al . observed LARC with a slow frequency of approximately 4 cycles/minute in anesthetized rats,[ 18 ] Byrne et al, identified a slow LARC frequency of 1.8 cycles/minute in rabbit detrusor strips,[ 7 ] and Lentle et al .…”

Section: Discussionmentioning

confidence: 99%

Automated quantification of low amplitude rhythmic contractions (LARC) during real-world urodynamics identifies a potential detrusor overactivity subgroup

et al. 2018

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ObjectivesDetrusor overactivity (DO) is characterized by non-voiding detrusor smooth muscle contractions during the bladder filling phase and often contributes to overactive bladder. In some patients DO is observed as isolated or sporadic contractions, while in others DO is manifested as low amplitude rhythmic contractions (LARC). The aim of this study was to develop an objective method to quantify LARC frequencies and amplitudes in urodynamic studies (UDS) and identify a subgroup DO of patients with LARC.MethodsAn automated Fast Fourier Transform (FFT) algorithm was developed to analyze a 205-second region of interest of retrospectively collected “real-world” UDS ending 30 seconds before voiding. The algorithm was designed to identify the three largest rhythmic amplitude peaks in vesical pressure (Pves) in the 1.75–6 cycle/minute frequency range. These peak Pves amplitudes were analyzed to determine whether they were 1) significant (above baseline Pves activity) and 2) independent (distinct from any in abdominal pressure (Pabd) rhythm).Results95 UDS met criteria for inclusion and were analyzed with the FFT algorithm. During a blinded visual analysis, a neurourologist/urodynamicist identified 52/95 (55%) patients as having DO. The FFT algorithm identified significant and independent (S&I) LARC in 14/52 (27%) patients with DO and 0/43 patients (0%) without DO, resulting in 100% specificity and a significant association (Fischer’s exact test, p<0.0001). The average slowest S&I LARC frequency in this DO subgroup was 3.20±0.34 cycles/min with an amplitude of 8.40±1.30 cm-H2O. This algorithm can analyze individual UDS in under 5 seconds, allowing real-time interpretation.ConclusionsAn FFT algorithm can be applied to “real-world” UDS to automatically characterize the frequency and amplitude of underlying LARC. This algorithm identified a potential subgroup of DO patients with LARC.

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A new and automated method for objective analysis of detrusor rhythm during the filling phase

Cited by 2 publications

References 20 publications

Evidence for a common mechanism for spontaneous rhythmic contraction and myogenic contraction induced by quick stretch in detrusor smooth muscle

Evidence for a common mechanism for spontaneous rhythmic contraction and myogenic contraction induced by quick stretch in detrusor smooth muscle

Automated quantification of low amplitude rhythmic contractions (LARC) during real-world urodynamics identifies a potential detrusor overactivity subgroup

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