Effects of therapy based on tilt testing results on the long-term outcome in patients with syncope.

BACKGROUND: The use of tilt testing (TT) in guiding therapy in patients with syncope remains controversial. AIM: To assess the long-term effectiveness of TT-based therapy in patients with syncope of unknown origin. METHODS: The study group consisted of 340 patients (182 females, mean age 38.2+/-16.5 years, range 15-78 years) with at least two syncopal episodes during 6 months preceding the study. TT was performed at 60 degrees angle for 20 min, followed by sublingual nitroglycerine (NTG) challenge (250 microg) when necessary. After positive baseline TT and returning to supine position, 0.1 mg/kg of propranolol was intravenously administered and a second TT was performed. All patients with positive TT were advised to take propranolol, midodrine or fludrocortisone for 6 months -- the choice of agent was based on standard criteria. The time to first syncope was an indicator of the efficacy of treatment and a recurrence of syncope was the end-point of the study. In patients who did not faint during follow-up, the last date of contact was taken as the end of observation period. RESULTS: Out of 340 patients who underwent TT, 148 with positive TT and propranolol challenge were included in the study; 82 patients (group I) received long-term therapy whereas 66 did not (group II). During a 12.8+/-0.9 month follow-up, syncope recurred in 86 patients - 40 (49%) from group I and 46 (70%) from group II (p<0.01). Survival analysis showed that medical therapy was associated with a significant reduction of the risk of syncope recurrence (RRR: 36%, 95% CI: 23-47). The greatest benefit from long-term treatment was documented in patients taking propranolol (RRR: 42%; 95% CI: 18-58; p<0.008), particularly in those in whom intravenous propranolol prevented TT-induced syncope (RRR: 50%; 95% CI: 23-67; p<0.012). Risk reduction in patients treated with midodrine or fludrocortisone was moderate (RRR: 22%; 95% CI: 11-34; p>0.09). CONCLUSIONS: Carefully selected and TT-based long-term pharmacological treatment is associated with a 36% risk reduction of syncope recurrences in patients with syncope of unknown origin.

[Remote repeatability of tilt test]. / Powtarzalnosc odlegla testu pionizacyjnego.

The aim of this study was the assessment of long-term repeatability of tilt-table test and parameters of heart rate variability analysis. Westminster protocol tilt-table test extended with nitroglycerin test was combined with analysis of heart rate variability. Five-minute intervals of ECG record were evaluated before and after the upright tilting, before syncope and 24-hour record was analysed. The test was performed in duplicate in 27 persons including 14 men (mean age 33 +/- 13.5) at interval of 29 +/- 13 months. The patients were then observed for 14 +/- 11.4 months. The study subjects were divided into groups with and without the recurrence of syncope. Repeatability was observed in 76.5% in positive test result and in 70% in negative test result. A low repeatability of positive test was observed. Blood pressure, heart rate and heart rate variability analysis parameters demonstrated a high repeatability during both tests. The recurrence of syncope was observed in 10 (37%) persons. The patients with both tilt tests positive, demonstrated recurrence of syncope two times more frequently what makes that the identification of the patients at risk for syncope return is easier.