Background: Tilt-table testing is safe and low-risk, but asystole of variable duration may be tilt-induced and, it was suggested that it could represent a life-threatening manifestation of vasovagal syncope. We performed a retrospective observational study evaluating the clinical characteristics and long-term outcome in patients with asystole during tilt-induced syncope.
Methods: A cohort of 552 patients referred for evaluation of recurrent syncope of unknown etiology underwent to a modified passive and active protocol tilt-table testing.
Results: 68% were positive to neurally mediated reflex syncope with 41 (11%) cases of asystole. Twenty-eight women (68%), mean age 26 ± 13 years and thirteen men, 31 ± 7 years had syncope with asystolic pause = 3 seconds during baseline, 27 of 41 (66%) or pharmacological challenge test, 14 of 41 (34%). The mean duration of asystole was 12.6 ± 11.3 seconds and, 80% of cases had sinus arrest = 5 seconds. 32 of 41 (78%) patients were successfully followed-up during a mean of 5.3 ± 1.5 years (range 1.5 to 8); 87.5% of patients had = 5 years of follow-up. Therapy was not guided based on the results of tilt-table testing and pharmacologic therapy with ß-blockers was generally effective. During long-term follow-up, only 12.5% had syncope recurrence and in 37.5% drugs were withdrawn after a long asymptomatic period.
Conclusion: Asystole during tilt-induced syncope does not necessarily predict adverse outcomes with most patients having a benign clinical course and improving with lifestyle changes and pharmacologic therapy and even spontaneously over a long-term follow-up.
Asystole, Vasovagal syncope, Tilt-table test, Cardioinhibitory syncope, Vasodepressor syncope, Neurocardiogenic syncope, Tilt-induced asystole