Economical selection of syncope patients for permanent cardiac pacing: a tilted view

Syncope is a common clinical problem, which raises a high degree of anxiety among both patients and physicians alike. Even when the cause of syncope is benign, recurrent syncopes (and the subsequent falls they produce) can result not only in injury but also in a similar amount of functional impairment that is seen in chronic disorders such as rheumatoid arthritis. One of the most frequent types of syncope is vasovagal syncope (VVS) or neurocardiogenic syncope. Investigations into the nature of the disorder were hampered by the lack of an effective modality for reproducing the syncopal event, as well as a relative inability to observe and make recording during spontaneous events.1 In the mid-1980s, investigators in London explored the concept that an individual's predisposition to VVS could be uncovered through the employment of a strong orthostatic stimulus such as gravitational one produced by prolonged upright posture. Since the publication of the landmark paper by Kenny et al 2 in 1986, subsequent investigations found that head-upright tilt-table testing (HUTT) is an effective and safe means of assessing a patient's predisposition to VVS. At the same time, the ability to reproduce syncopal episodes in the controlled laboratory settings provided a unique opportunity to make a variety of physiological measurements that greatly increased the knowledge of not only VVS but also the related disorders.3 In some individuals, these HUTT-induced episodes of VVS were accompanied by profound bradycardia and sometimes asystole. It seemed logical …