Reproducibility of Tilt-table Test with Different Dosages of Sublingual Nitroglycerin

INTRODUCTION: Reproducibility of tilt-table test potentiated with sublingual nitrate is significant since it is directly related to diagnostic accuracy of the test. Nitrates shorten the test time and increase the sensitivity of the test. However the effects of different nitrate dosages on reproducibility have not been reported. Therefore we aimed to investigate the effects of 400 mcg, 800 mcg, and 1200 mcg sublingual spray nitroglycerin on reproducibility of tilt-table test.
METHODS: All patients undergoing tilt-table test at our hospital due to suspected syncope evaluated and patients giving consent included. First group received 400 mcg, second group received 800 mcg, and third group received 1200 mcg sublingual spray nitroglycerin. Patients underwent a second test with a same protocol within 1-7 days following the initial test.
RESULTS: Overall 189 patients included in this study. All of the patients in the first (n=62) and the second group (n=66) completed the initial test whereas 2 patients in the third group (n=65) terminated the initial test due to severe headache related to nitroglycerin. Five patients in the third group gave exaggerated response. The overall reproducibility of tilt-tablets was 81.9%, 88.9%, 82.1%, in the first, second, and third group, respectively. There was no statistically sigficant reproducibility difference between groups.
DISCUSSION AND CONCLUSION: The reproducibility of tilt-table test is similar with different dosages of sublingual nitroglycerin; however 1200 mcg nitroglycerin has more frequent side effects and exaggerated response.