beta-adrenergic receptor blockers and the treatment of vasovagal syncope: more nails in the coffin!
beta-Adrenergic receptor blockers are one of a number of therapeutic agents promoted as having beneficial effects in vasovagal syncope. In this issue of Clinical Science, Eldadah and co-workers have investigated the effect of the beta-adrenergic receptor blocker propranolol in preventing syncope in a double-blind cross-over trial in eight subjects with a diagnosis based on tilt table testing and elevated plasma adrenaline levels during syncope. Of these, seven did not respond and the authors therefore suggest that this drug has no role in the management of vasovagal syncope. Their laboratory-based study, however, raises a number of issues regarding terminology, choice of subjects, the value and role of investigations directed towards diagnosis and in understanding pathophysiological mechanisms, and the relevance of such trials to individual subjects with vasovagal syncope.
Mathias
Christopher J
CJ
Neurovascular Medicine Unit, Faculty of Medicine, Imperial College London at St Mary's Hospital, Praed Street, London W2 1NY, UK. c.mathias@imperial.ac.uk
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D006801:Humans; D011433:Propranolol / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D012107:Research Design; D019462:Syncope, Vasovagal / Q000188:drug therapy*; D018667:Tilt-Table Test; D017211:Treatment Failure
D000319:Adrenergic beta-Antagonists; D011433:Propranolol