PURPOSE : The aim of the study was to evaluate the renin-angiotensin system and serotonin transporter gene polymorphisms in relation to hemodynamic parameters and heart rate variability during a head-up tilt test ( HUT ) in patients with vasovagal syncope .
O O O O O O O O O O O I-GeneOrGeneProduct O O B-GeneOrGeneProduct I-GeneOrGeneProduct O O O O O O O O O O O O O O O O O O O O B-OrganismTaxon O B-DiseaseOrPhenotypicFeature I-DiseaseOrPhenotypicFeature O