From the Research
Bladder retention can indeed cause bradycardia through a mechanism known as the vasovagal response, and immediate treatment involves bladder decompression through catheterization, which typically resolves the bradycardia within minutes, as seen in a case of BRASH syndrome where bradycardia resolved upon treatment of hyperkalemia 1.
Mechanism and Treatment
The vasovagal response is triggered by the distension of the bladder, stimulating the vagus nerve and leading to a decrease in heart rate and sometimes a drop in blood pressure. This phenomenon is particularly common in elderly patients and those with neurological conditions.
- The immediate treatment involves bladder decompression through catheterization, which typically resolves the bradycardia within minutes.
- For patients experiencing this condition, prompt bladder drainage with a Foley catheter (14-16 French) should be performed, with careful monitoring of vital signs during and after the procedure.
- If bradycardia persists after bladder decompression, further cardiac evaluation may be necessary.
Preventing Recurrence
In cases where this occurs repeatedly, a urological consultation should be sought to address the underlying bladder dysfunction.
- The physiological basis for this response involves autonomic nervous system activation, where bladder distension triggers parasympathetic stimulation via the vagus nerve, overriding sympathetic tone and resulting in decreased heart rate.
- Preventing recurrence involves regular bladder emptying schedules or intermittent catheterization for those with chronic retention issues.
- Alpha-blockers may be useful in some cases, particularly in patients with primary bladder neck obstruction, but their effectiveness can be predicted by factors such as age, voiding pressure, and bladder outlet obstruction index 2.