title: Use of sublingual nitroglycerin during head-up tilt-table testing in patients >60 years of age.
abstract: Previous work had demonstrated a reduced specificity associated with head-up tilt protocols using high-dose isoproterenol in patients between 20 and 50 years of age. We evaluated the specificity of head-up tilt testing using different isoproterenol infusion doses and administration of nitroglycerin in patients aged >60 years. In addition, whether the same protocols have impact on the sensitivity of the test was also assessed. One hundred sixty subjects were included in this study. Seventy-six were volunteers randomized to either head-up tilt test with low-dose, 3- and 5-microg/min of isoproterenol (group I) or to a protocol including 0.4 mg of sublingual nitroglycerin (group II). In addition, after an upright tilt drug-free state, 58 patients with a history of syncope underwent repeat head-up tilt with increasing doses of isoproterenol infusion, followed by sublingual nitroglycerin if the test result remained negative. The remaining 33 patients were subjected to the nitroglycerin protocol after the drug-free state phase. In the control groups, the incidence of false-positive responses was 88% and 95%, respectively. In patients with syncope after a negative test result during 5 microg of isoproterenol infusion, nitroglycerin administration increased the number of positive responses from 45% to 79%. The percentage of positive tilt in patients undergoing nitroglycerin administration after the drug-free state part of the protocol was 78%. Administration of nitroglycerin was the most significant predictor of a positive upright tilt in patients with syncope. In subjects aged >60 years, head-up tilt protocols with high-dose isoproterenol infusion and nitroglycerin maintained an adequate specificity. In this subset of patients, nitroglycerin seemed to provide a better sensitivity than isoproterenol.
authors.affiliation: University of Kentucky, Lexington, USA.
authors.forename: A
authors.initials: A
authors.lastname: Natale
authors.forename: J
authors.initials: J
authors.lastname: Sra
authors.forename: M
authors.initials: M
authors.lastname: Akhtar
authors.forename: L
authors.initials: L
authors.lastname: Kusmirek
authors.forename: G
authors.initials: G
authors.lastname: Tomassoni
authors.forename: F
authors.initials: F
authors.lastname: Leonelli
authors.forename: K
authors.initials: K
authors.lastname: Newby
authors.forename: S
authors.initials: S
authors.lastname: Beheiry
authors.forename: A
authors.initials: A
authors.lastname: Pacifico
mesh_terms: D000286:Administration, Sublingual; D000368:Aged; D001919:Bradycardia / Q000150:complications / Q000175:diagnosis*; D002316:Cardiotonic Agents / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007545:Isoproterenol / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage; D012680:Sensitivity and Specificity; D013575:Syncope / Q000139:chemically induced / Q000209:etiology*; D018667:Tilt-Table Test; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D002316:Cardiotonic Agents; D014665:Vasodilator Agents; D005996:Nitroglycerin; D007545:Isoproterenol