Post-micturitional hypotension in patients with multiple system atrophy

Abstract

Background: Patients with multiple system atrophy (MSA) occasionally have episodes of syncope or presyncope after micturition. Objective: To clarify the mechanism of these episodes by investigating the haemodynamic changes associated with micturition. Methods: 25 patients with probable MSA and 16 age matched normal controls were studied. Continuous records of blood pressure and heart rate were made during water cystometry, along with the Valsalva manoeuvre, head up tilt testing, measurement of plasma noradrenaline, and calculation of coefficient of variance of RR intervals. Results: Compared with normal controls, MSA patients had a lower baseline blood pressure, smaller blood pressure and heart rate increases during bladder filling, and an abnormal fall in blood pressure for a longer duration after voiding, resulting in significantly lower blood pressure than at baseline (mean systolic blood pressure reduction 215.2 mm Hg), and hypotension compared with control blood pressure (229.0 mm Hg). The blood pressure fall was greater in patients with micturition syncope/pre-syncope than in those without. It was also greater in patients with abdominal straining resulting from difficulty in voiding. Other cardiovascular indices did not correlate with the fall in blood pressure. Conclusions: Hypotension after voiding in MSA patients may result from generalised autonomic dysfunction and abnormal abdominal straining, resulting in micturition syncope.

Incomplete emptying and urinary retention in multiple‐system atrophy: When does it occur and how do we manage it?

“…In our patients, CISC ameliorated urinary frequency and urgency since it increased functional bladder capacity. In our MSA patients with micturition syncope, CISC also reduced the number of syncope episodes, presumably by reducing abdominal strain 32. However, in the MSA patients with DHIC or nocturnal polyuria,33 frequent CISC is a bother, particularly at night.…”

Severe hypotension following urethral catheterization during general anesthesia in a patient with bladder cancer -A case report-

“…These episodes usually present as bradycardia, hypotension, and loss of consciousness, and the event usually lasts less than 30 min with full recovery. Circulatory disturbances, such as standing position, alcohol consumption, airway infection, fatigue, warmth, hypnic deprivation, and the valsalva maneuver are known trigger factors of micturition syncope [ 2 , 6 - 8 ]. Sumiyoshi et al [ 9 ] studied age-dependent clinical characteristics of micturition syncope.…”

“…The process of micturition is related to activation of the cardiovascular autonomic nervous system. That is, cardiovascular autonomic activity in which the blood pressure (BP) and the heart rate (HR) are reduced due to a sudden pressure reduction of the expanded bladder correlates with urinary autonomic activity, in which the sympathetic supply is inhibited and the parasympathetic supply is excited [ 2 ]. We report on a patient who was treated with urethral dilatation and transurethral resection of bladder tumor (TURBT) while under general anesthesia and who experienced severe hypotension after insertion of the urinary catheter.…”

Micturition syncope following intermittent catheterisation in a tetraplegic patient

“…5,9 This phenomenon can be more pronounced in SCI patients at T6 level and above, as the systolic blood pressure is often increased when the bladder is distended or contracts, as part of autonomic dysreflexia. 10 The subsequent fall of blood pressure is then even more dramatic.…”