[Haemodynamic instability induced by carotid stent implantation]

Intravascular stent implantation is an attractive therapy for carotid artery stenosis. Severe complications of the interventional procedure however include stroke and death.

It has been suggested, that episodes of temporary bradycardia and hypotension upon balloon inflation could be related to adverse outcome.

In order to assess the significance of episodic haemodynamic instability 24 consecutive patients were continuously monitored during intravascular intervention. Heart rate and blood pressure variability parameters of the patients, and indices of spontaneous baroreflex sensitivity were determined prior to the procedures. The authors have assessed the potential correlation between the autonomic markers recorded on baseline and the subsequent occurrence of reflex mediated haemodynamic instability.

The authors observations confirmed that bradycardia and hypotension occurs frequently at the time of stent after-dilation. Pauses in excess of 3 seconds occurred in 29% of patients. Atropine was administered at 7 instances. The magnitude of systolic blood pressure drop was greater among patients with pauses, however substantial pressure drop was seen among those without pauses as well. No severe complications were seen. Heart rate variability and spontaneous baroreflex sensitivity were reduced in the whole studied population, allowing no prediction of episodes with bradycardia and hypotension.

The authors findings indicate that reflex mediated haemodynamic instability induced by carotid artery intervention is a benign phenomenon. Analysis of autonomic markers is of limited value in this patient population.