Abstract 4121: Clomipramine Infusion During Tilt Test To Imply The Neurocardiogenic Origin Of Syncopes And Presyncopes Of Unknown Aetiology
The aim of this study was to prospectively evaluate the diagnostic accuracy for neurocardiogenic syncopes (NCS) of two Head-Up Tilt table test (HUT) strategies in 991 patients with syncopes/presyncopes of unknown aetiology after negative clinical and non invasive investigations. HUT is a widely accepted tool in the evaluation of patients with evidence of VVS but questions remain about the sensitivity and the use of provocative agents.Clomipramine (CP), a serotonin re-uptake inhibitor, was recently proposed as a new drug challenge test for the diagnosis of neurocardiogenic syncope (NCS). Group A : the first 341 pts (207 male ; mean age = 49,9 ± 23 years) were passively tilted at 60° for 30 minutes (min), then for 15 min with 2 μg/min isoproterenol infusion rate. Group B : the following 650 pts (383 male ; mean age = 48,3 ± 21 years) were tilted at 60° for 20 min with 5 mg CP infused during the first 5 min of tilt. A positive HUT was defined as reproducting the patient’s syncope or presyncope, associated with an abrupt fall in blood pressure (systolic blood pressure <80 mmHg) and/or concomitant bradycardia (<50 beats/min). Positives responses were classified in 3 types according to the Brignole’s modification of the VASIS classification. There was no significant difference between group A/B in sex or age. Group A : Positive HUT* : 103 (Sensitivity : 30,2%) Group B : Positive HUT* : 382 (Sensitivity : 58,8 %) (*) type 1 : 36 vs 157 ; type 2A : 8 vs 13 ; Type 2B: 9 vs 57 (14,9%) ; Type 3 : 50 vs 155. No adverse effect was noticed. CP during HUT increase significantly the accuracy of the test for NCS diagnosis, especially for type 2B answers, and patients <30 yo. The duration of the test is notably shortened, and the tolerance is remarkable. If previously reported specificity (87 to 94%) was confirmed, CP-HUT might be the most valuable tool in the evaluation of pts with syncopes/presyncopes of unknown aetiology.