The Role of Tilt-table Test in Differential Diagnosis of Unexplained Syncope.

The aim of this retrospective study (February 2012-September 2014) was to assess the role of head-up tilt-table test in patients with unexplained syncope. It was performed on 235 patients at Clinical Department of Cardiology, Sestre milosrdnice University Hospital Center. Patients were classified according to test indications: group A (convulsive syncope, n = 30), group B (suspected vasovagal syncope, n = 180), and group C (paroxysmal vertigo, n = 25). The groups were analyzed and compared according to demographic data (age and gender), referral specialist (cardiologist, neurologist, and others), and test results (positive/negative) with specific response (cardioinhibitory, vasodepressor, or mixed). Groups A and B were referred most frequently by neurologists and cardiologists (p < 0.05). The test was positive in 34 (14.5%) of all evaluated patients (5 in group A and 29 in group B), of which 13 (38.2%) had cardioinhibitory, 11 (32.4%) mixed and 10 (29.4%) vasodepressor response. In the cardioinhibitory subgroup, three patients (23.1%, 2 males/1 female, mean age 28.5 years) with normal electroencephalography were on antiepileptics. During head-up tilt-table testing, they had bradycardia (heart rate 30.0 ± 5.0 beats/min) and prolonged asystole (13.7 ± 11.0 seconds) with development of typical convulsions. These three subjects got a permanent pacemaker (atrial/ventricular stimulation, heart rate control) and anticonvulsive therapy was slowly withdrawn with no syncope recurrence during 24-month follow up. In conclusion, head-up tilt-table test has an important role in the evaluation of patients with unexplained syncope and in differential diagnosis of vasovagal syncope. The indication for pacemaker implantation, strictly following the European Society of Cardiology guidelines, proved to be effective in preventing syncope relapses in patients with cardioinhibitory convulsive syncope.