Carotid sinus hypersensitivity and the carotid sinus syndrome

E STABLISHING the correct diagnosis for the causative mechanism of syncope is still a medical challenge. Since syncope may be caused by a variety of mechanisms, and since usually the patient arrives for medical attention after the episode has subsided, establishing the proper diagnosis is a difficult task that requires the performance of a variety of tests to rule out possible causes. In addition, since syncope may imply such a variable prognosis, the need to make a correct diagnosis is mandatory. Carotid sinus hypersensitivity (CSH) is a known cause of syncope. Even though it was described long ago, it was not until recent years that its presence and significance became more widely recognized. Nonetheless, we believe that CSH is still a relatively overlooked cause of syncope.’ This is partly related to the difficulty of establishing a clear-cut cause and effect relationship between CSH demonstrated at bedside or in the laboratory, and the patient’s previous syncopal attacks.