Recurrent vasovagal syncope: comparison between clomipramine and nitroglycerin as drug challenges during head-up tilt testing
Flevari P et al. – In evaluation of pts with recurrent classical vasovagal syncope (VVS), clomipramine tilt is associated with an increased positive yield relative to nitroglycerin tilt. This finding suggests that central mechanisms may be more important than peripheral mechanisms in VVS pathogenesis. Methods- Comparison of responses between clomipramine, a centrally acting substance, and nitroglycerin, with mainly peripheral action
- Use of each drug during tilt test for induction of VVS
- Randomized sequence of 2 tilt tests in 100 pts with recurrent episodes of classic VVS
- Test 1: 20 min of 60° tilt with intravenous administration of 5 mg clomipramine (clomipramine tilt)
- Test 2: initial 30 min period of passive 60° tilt, followed by sublingual spray administration of 400 microg nitroglycerin (nitroglycerin tilt)
- Controls: 50 asymptomatic subjects
Results- After clomipramine tilt, positive response in 73 pts (73%), negative response in 23 (23%), and drug intolerance in 4 (4%)
- With nitroglycerin tilt, percentages were 52%, 48%, and 0%, respectively
- Significant differences for positive responses (clomipramine vs nitroglycerin: 73/100 vs 52/100) and negative responses (23/100 vs 48/100, respectively)
- Hgh concordance rate in positive responses
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