Summary

We describe a case of reproducible asystole during endovascular treatment of a posterior fossa dural arteriovenous fistula. Catheterisation of the posterior meningeal artery, a branch of the vertebral artery in this patient, followed by dimethyl sulfoxide injection prior to Onyx administration resulted in two episodes of asystole.

To the best of our knowledge, this is the first reported case of asystole occurring during endovascular intervention in the posterior meningeal artery. This may represent a previously undescribed variant of the trigemino-cardiac reflex (TGCR) caused by chemical stimulation of small areas of trigeminally innervated posterior fossa dura. Alternatively, this may represent a newly identified phenomenon with chemical stimulation of regions of posterior fossa dura innervated by branches of the vagus nerve leading to increased parasympathetic activity and resultant asystole.

In either case, it is important to recognise the potential for such episodes in this vascular territory to allow case planning and management.