Carotid sinus hypersensitivity: Entity warrants a caution in the critical care unit

Abstract

Carotid sinus hypersensitivity (CSH) syndrome is an entity caused by an overreaction of the carotid sinus baroreceptors to stimulation. Three subtypes of CSH syndrome are recognized according to the response to carotid sinus massage (CSM): Predominantly cardioinhibitory, predominantly vasodepressor and a mixed subtype. We report here the case of a middle-aged female patient admitted in our critical care unit with respiratory failure requiring mechanical ventilation. There were episodes of severe bradycardia whenever her head was rotated to any side, relieved on neutralizing head position and administering intravenous atropine. CSM revealed she had predominantly cardioinhibitory type of CSH syndrome. A cardioinhibitory form of hypersensitive carotid sinus reflex, which is idiopathic in causation, probably explains the severe bradycardia on head rotation seen in our patient. A heightened awareness of this syndrome is necessary for timely diagnosis and management. CSH syndrome results from an overreaction of the carotid sinus baroreceptors to stimulation, manifesting commonly as bradycardia, hypotension and syncope. It is an entity, which warrants caution during routine critical care practices.

Keywords

• Airway reflexes
• cardiovascular system responses
• carotid sinus hypersensitivity