title: [Tilt test: hemodynamic responses in patients with syncope or presyncope of unknown etiology].
abstract: The aim of this work was to assess the hemodynamic responses to the tilt test of 51 patients with syncope (n = 31) or presyncope (n = 20) of unknown etiology. A protocol with an inclination of 70 degrees (20 min) with or without isoproterenol (mean dose of 3.6 +/- 0.3 ug/min), was used. Forty five percent of patients had a positive test, 18 with isoproterenol at 70 degrees (group 1A) and 5 without isoproterenol (group 1B); 28 patients had a negative test (group 2). These groups did not differ in age or sex distribution. Basal heart rate was 76.2 +/- 2x'. At the end of the test it was 73.4 +/- 5.7 in group 1A, 78.0 +/- 7.5 in group 1B and 120.4 +/- 3.3 in group 2 (p < 0.01). Systolic blood pressure decreased to 78.1 +/- 4.8 mmHg in group 1A, to 76.2 +/- 9.9 in group 1B and did not decrease in group B (130.0 +/- 5.7 mmHg, p < 0.01). The required dose of isoproterenol was higher in group 1A than in group 2 (4.4 +/- 0.3 vs 3.1 +/- ug/min, p < 0.01). It is concluded that the tilt test reproduced symptoms and accompanying hemodynamic mechanisms in a high proportion of patients with syncope of unknown etiology. This test should be incorporated in the diagnostic workup of these patients.
authors.affiliation: Pontificia Universidad Católica, Departamento de Enfermedades Cardiovasculares, Santiago de Chile.
authors.forename: J
authors.initials: J
authors.lastname: Jalil
authors.forename: F J
authors.initials: FJ
authors.lastname: Radrigán
authors.forename: R
authors.initials: R
authors.lastname: González
authors.forename: I
authors.initials: I
authors.lastname: Godoy
authors.forename: A
authors.initials: A
authors.lastname: Fajuri
authors.forename: G
authors.initials: G
authors.lastname: Chamorro
authors.forename: P
authors.initials: P
authors.lastname: Casanegra
authors.forename: C
authors.initials: C
authors.lastname: Valenzuela
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006339:Heart Rate; D006801:Humans; D007024:Hypotension, Orthostatic / Q000503:physiopathology; D007545:Isoproterenol; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D012680:Sensitivity and Specificity; D013575:Syncope / Q000503:physiopathology*
chemical_list: D007545:Isoproterenol
vernacular_title: Prueba de inclinación (tilt test): respuestas hemodinámicas en pacientes con síncope o presíncope de etiología no precisada.