Role of pacing in the treatment of vasovagal syncope

Patients with frequent vasovagal syncope have a markedly poor quality of li fe and are often resistant to treatment by standard pharmacologic approache s. Although the evidence is not conclusive, clinical vasovagal syncope is p robably associated with some degree of bradycardia, Studies of temporary pa cing during tilt-table testing have shown that pacing prevents syncope in m ore than half of patients who develop a vasovagal response, Three open-labe l studies of permanent pacing showed that pacing was associated with substa ntial improvement, and the prospective randomized Vasovagal Pacemaker Study reported an 85% relative risk reduction in patients randomized to pacemake r therapy compared with medical therapy, The roles of specific pacemaker mo des in vasovagal syncope have not been determined, although early evidence indicates that rate-drop responsiveness is useful. The second Vasovagal Pac emaker Study may clarify the role of rate-drop responsiveness. (C) 1999 by Excerpta Medico, Inc.