Arterial stiffness and the response to carotid sinus massage in older adults

Abstract

Background and aims-Carotid sinus hypersensitivity (CSH) is a common cause of fainting and falls in the older adult population and is diagnosed by carotid sinus massage (CSM). Previous work has suggested that age-related stiffening of blood vessels reduces afferent input from the carotid sinus leading to central upregulation of the overall arterial baroreflex response. We examined the differences in arterial stiffness and baroreflex function in older adults at high cardiovascular risk (advanced age, Type 2 diabetes, hypertension and hyperlipidemia) with and without CSH.

Carotid sinus hypersensitivity: block of the sternocleidomastoid muscle does not affect responses to carotid sinus massage in healthy young adults

“…While patients with CSH do exhibit increased arterial stiffening (Madden et al. ), efforts to investigate the mechanism of increased central gain have been unsuccessful (Kenny et al. ; Parry et al.…”

Aerobic training in older adults with type 2 diabetes and vasodepressive carotid sinus hypersensitivity

“…In OADM subjects, an upregulation of alpha-1 receptors in response to a drop in afferent input may be resulting in an overshoot response and consequent syncopal spells [7,8]. However, central upregulation leading to baroreflex over-sensitivity as a explanation for CSH has been questioned by other investigations; previous work in older adult subjects has demonstrated a reduction in baroreflex sensitivity (as opposed to an increase in baroreflex sensitivity) in subjects with CSH, suggesting that other mechanisms are responsible for this condition [9]. It is well established that aerobic exercise reduces arterial stiffness in older adults [10].…”

“…An upregulation of alpha-1 receptors in response to an agerelated drop in afferent input may be resulting in an overshoot response to normal swings in blood pressure and consequent vasodepression-related fainting [7,8]. Human studies have demonstrated increased arterial stiffness in subjects with V-CSH [9]. One therapy that has been shown to reverse arterial stiffening in older adults is aerobic exercise [10] suggesting that aerobic training has the potential to reverse carotid sinus hypersensitivity.…”

Should We Ever Pace for Carotid Sinus Syndrome?

“…If the alpha-2 adrenoceptor hypothesis was true, the hemodynamic responses to yohimbine should be markedly attenuated-this was not the case (Figure 6) (56). More recently, 10 older adults with CSH had higher arterial stiffness and reduced arterial baroreflex sensitivity compared to those without, further providing no evidence to support the upregulation of the arterial baroreflex in patients with CSH (57).…”