Abstract 13334: Association Between Orthostatic Hypotension and Results of the Head-Up Table Testing

Abstract

Background: There is a weak correlation between clinical variables of syncopal patients and the result of Head-up Tilt Table Testing (TT). Orthostatic hypotension is one of the frequent causes of syncope that can have a predictive value in the result of TT.

Objective: To establish the predictive value of orthostatic hypotension in the positive result of TT.

Patients: Cross-sectional study. A total of 722 patients were evaluated by the tilt test (TT). The sample included 417 women (58%), and the mean age was 43±22 years.

Results: Positive TT results were observed for 305 (42%) patients among the total sample, with higher frequency among women (48%) than among men (35%) (P= 0.001). Eighty patients (11.1%) had orthostatic hypotension (OH), and 60 of them (75%) had positive TT results. Among the 642 patients without Orthostatic hypotension, 249 (39%) had positive TT results (P< 0.001). When the sample was stratified by age (2-22; 23-42; 43-62; 63-90 years old), Poisson regression with a robust error variance analysis showed that the first two quarters had greater probability to present positive results (P=0.001 and P<0.05) than the last one (PR 1.3; CI 95% 1.06 to 1.68 and PR 1.3; CI 95% 1.02 to 1.63). The presence of Orthostatic hypotension (PR 2; CI 95%: 1.7 to 2.4) and female gender (PR:1.2; CI 95%: 1.03 to 1.46) were associated to positive TT results (P<0.05 ). The frequency of positive TT results was lower among women using oral contraceptives (14.8%) than among the remaining female patients (48.6%) (P<0.01 ). No other drugs were shown to affect TT results.

Conclusion: Orthostatic hypotension is strongly related to positive TT results. Female gender and young age were also associated to positive TT, and Orthostatic hypotension favored negative TT results.