Elderly patients with unexplained syncope: what should be considered a positive tilt test response?

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.