Elderly patients with unexplained syncope: What should be considered a positive tilt test response? Renata Rodrigues Teixeira de Castro, Antonio Claudio Lucas da Nobrega * Cardiovascular and Autonomic Reactivity Laboratory, Syncope Unit and PROCEP, Hospital Pro ´-Cardı ´aco, Physiology and Pharmacology Department, Universidade Federal Fluminense, Rio de Janeiro, Brazil Received 29 October 2005; received in revised form 15 April 2006; accepted 3 May 2006 Abstract Introduction: Syncope is a common problem and can lead to serious consequences in the elderly. Tilt test is useful to investigate recurrent syncope, but few studies have investigated the hemodynamic responses of this population to tilt test. Objective: To describe the tilt test responses of elderly patients with recurrent syncope of unknown origin and to determine the occurrence of altered cardiovascular autonomic function in a subset of those with the diagnosis of dysautonomic pattern to the tilt test. Methods: Elderly patients (n = 165; > 60 years old) who sought medical assistance because of recurrent syncope during 18 months were initially enrolled and submitted to a two-stage, nitroglycerin-potentiated tilt test. A subset of patients who presented with dysautonomic response to tilt test performed clinical autonomic tests. Results: The most frequent cause of syncope during tilt test was the dysautonomic pattern (43%), followed by mixed type neurocardiogenic syncope (35%). Most patients who remained asymptomatic during tilt test showed clear abnormal hemodynamic response during the exam. Conclusion: Autonomic dysfunction, which can be found during tilt test, is probably an important cause of syncope in the elderly, regardless of the occurrence of symptoms during the tilt test. D 2006 Elsevier B.V. All rights reserved. Keywords: Till test; Syncope; Elderly; Autonomic dysfunction; Autonomic nervous system 1. Introduction Syncope, defined as the sudden loss of consciousness and postural tone with spontaneous recovery, is a very common problem, accounting for 1% of all hospital admissions and 3 – 5% of casualty department visits (Kapoor et al., 1982). In elderly people syncope is even more frequent. Among elderly confined to long-term care institutions, the annual incidence may be as high as 6%, with a recurrence rate of 30% and a 10-year incidence of 23% in people older than 70years old (Lipsitz et al., 1985). Syncope may present as a symptom of many different diseases, from benign ones, as neurocardiogenic syncope, to malignant and fatal others, as ventricular arrhythmias. Nevertheless, syncope is a potentially disabling problem, with a great impairment in physical and psychosocial function. In elderly patients, syncope is even more important because of the various consequences of falling to the ground, such as head trauma. Tilt test is a useful tool to investigate recurrent syncope (Brignole et al., 2004). During tilt test it is possible to evaluate blood pressure and heart rate responses to orthostatic stress and to vasodilator stimulus (usually sublingual administration of nitroglycerin). The main objective of tilt test is to determine which pattern of hemodynamic response is responsible for the occurrence of syncope or pre-syncope. On its turn, the pattern of hemodynamic response to tilt test may be a key factor to determine the cause of syncope, with direct clinical relevance as the prognosis may be quite different. Some patients with syncope can exhibit a dysautonomic response during tilt test (see Methods). This response, also 1566-0702/$ - see front matter D 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.autneu.2006.05.001 * Corresponding author. Hospital Pro ´ -Cardı ´aco, Lab de Reatividade Autono ˆmica e Cardiovascular, Rua Dona Mariana, 219, CEP: 22280-020, Botafogo, Rio de Janeiro, RJ, Brazil. Autonomic Neuroscience: Basic and Clinical 126 – 127 (2006) 169 – 173 www.elsevier.com/locate/autneu