Carotid sinus syndrome

The causes of syncope in patients with Alzheimer s disease treated with donepezil have been reported in 16 consecutive patients (12 women, 4 men) with Alzheimer s disease, mean age 80 years, who underwent staged evaluation, ranging from physical examination to electrophy-siological testing (54). The mean dose of donepezil was 7.8 mg/day and the mean duration of donepezil treatment at the time of syncope was 12 months. Among the causes of syncope, carotid sinus syndrome (n = 3), complete atrioventricular block (n = 2), sinus node dysfunction (n = 2), and paroxysmal atrial fibrillation (n = 1) were diagnosed. No cause of syncope was found in six patients. Non-invasive evaluation is recommended before withdrawing cholinesterase inhibitors in patients with Alzheimer s disease and unexplained syncope. 

Parry SW, Steen N, Baptist M et al. (2006). Cerebral autoregulation is impaired in cardioinhibitory carotid sinus syndrome. Heart 92 792-797... 

Strasberg B, Sagie A, Erdman S, et al. Carotid sinus hypersensitivity and the carotid sinus syndrome. Frog Cardiovasc Dis 1989 31 379-391. 

The two most frequent types of reflex syncopes are NCS and carotid sinus syndrome. While both can represent the consequences of augmented vagal tone with similar resultant clinical manifestations, NCS occurs in a vdifferent patient population and is often associated with sympathetic inhibition as described below. NCS can be quite varied in presentation (1). 

Table 13.2 Indications for permanent pacing in hypersensitive carotid sinus syndrome and neurally mediated syncope.

To reduce severe bradycardia in hyperactive carotid sinus reflex Diagnostically in Wolff-Parkinson-White syndrome, to restore the PRS complex to normal duration... 

Abnormalities of the internal carotid artery Unilateral vascular headache syndromes Direct or indirect trauma Spontaneous or traumatic occlusion Aneurysms Atherosclerosis Spontaneous dissection Lesions involving the middle cranial fossa and cavernous sinus Basal skull fractures... 

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