Characterization of heart rate changes associated with autonomic dysreflexia during penile vibrostimulation and urodynamics

Purpose Autonomic dysreflexia, often accompanied by heart rate changes, increases the risk of cardio-cerebrovascular complications in individuals with spinal cord injury. Thus, our aim was to characterize these changes during penile vibrostimulation and urodynamics. Materials and Methods We analyzed the cardiovascular (i.e. blood pressure and heart rate) data from two prospective studies, i.e. 21 individuals with chronic spinal cord injuries and history of autonomic dysreflexia, who underwent penile vibrostimulation (n=11, study 1) or urodynamics (n=10, study 2). Results The cohort’s median age was 41 years (range 22 −53). Overall 47 episodes of autonomic dysreflexia were recorded (i.e. penile vibrostimulation n=37, urodynamics n=10), while at least one episode was recorded in each participant. At the threshold of autonomic dysreflexia, bradycardia was observed during penile vibrostimulation and urodynamics in 43% and 30% of all episodes, respectively. At the peak of autonomic dysreflexia during penile vibrostimulation and urodynamics, bradycardia was observed in 65% and 50%, respectively. In contrast, tachycardia was detected only once during urodynamics. Conclusion Our findings reveal that heart rate changes associated with autonomic dysreflexia during penile vibrostimulation and urodynamics appear to be related to the magnitude of systolic blood pressure increases. Thus, highly elevated systolic blood pressure associated with bradycardia suggest the presence of severe autonomic dysreflexia, which can lead to devastating cerebro-cardiovascular consequences. Therefore, we recommend cardiovascular monitoring during penile vibrostimulation and urodynamics to detect autonomic dysreflexia and stop assessments before systolic blood pressure is dangerously increasing, thereby reducing the risk of potentially life-threatening complications in this cohort.