Randomized assessment of syncope trial - Conventional diagnostic testing versus a prolonged monitoring strategy

Background-Establishing a diagnosis in patients with unexplained syncope is complicated by infrequent and unpredictable events. Prolonged monitoring m ay be an alternative strategy to conventional testing with short-term monit oring and provocative tilt and electrophysiological testing. Methods and Results-Sixty patients (aged 66 +/- 14 years, 33 male) with une xplained syncope were randomized to "conventional" testing with an external loop recorder and tilt and electrophysiological testing or to prolonged mo nitoring with an implantable loop recorder with 1 year of monitoring. If pa tients remained undiagnosed after their assigned strategy, they were offere d crossover to the alternate strategy. A diagnosis was obtained in 14 of 27 patients randomized to prolonged monitoring compared with 6 of 30 patients undergoing conventional testing (52% versus 20%, P=0.012), Crossover was a ssociated with a diagnosis in I of 6 patients undergoing conventional testi ng compared with 8 of 13 patients who completed monitoring (17% versus 62%, P=0.069). Overall, prolonged monitoring was more likely to result in a dia gnosis than was conventional testing (55% versus 19%, P=0.0014). Bradycardi a was detected in 14 patients undergoing monitoring compared with 3 patient s undergoing conventional tasting (40% versus 8%, P=0.005). Conclusions-A prolonged monitoring strategy is more likely to provide a dia gnosis than conventional testing in patients with unexplained syncope. Cons ideration should be given to earlier implementation of a monitoring strateg y.