title: [Role of auxiliary diagnostic tests in the clarification of the etiology of syncope: experience at an arrhythmia center].
abstract: Syncope is a syndrome caused by a reversible reduction of blood to the brain. Three hemodynamic abnormalities can cause syncope: an acute decrease in cardiac output, an acute increase in cerebrovascular resistance and a fall in systemic blood pressure due to ineffective control of peripheral vascular resistance. We made a retrospective study of 121 patients with syncope history, 67 males, and 57 females, with mean age 48 +/- 14 years, and at least six months of clinical follow-up. Twelve patients had valvular disease, two patients had hypertrophic cardiomyopathy, eight patients had dilated cardiomyopathy, 14 patients had ischemic disease, three patients had congenital disease; 82 patients did not have cardiac disease. Syncope etiology was arrhythmic in 69 patients: 47 patients had tachyarrhythmia (supraventricular--in 27 patients and ventricular in 20 patients) and 15 patients had bradyarrhythmia (seven patients had sinus node disease and eight patients had atrioventricular block). Non arrhythmic etiology of syncope was identified in 29 patients (neurologic disease--ten patients, metabolic disease--one patient and iatrogenic--two patients; vasodepressor syncope--14 patients, and hypertrophic cardiomyopathy--two patients). It was not possible to determine the syncope etiology in 30 patients. The assessment of patients who present syncope depends on establishing the basis for the symptoms. The initial step is differentiating patients with normal cardiovascular systems from those with heart disease. In the former, tilt-table testing proved to be the most productive from a diagnostic perspective; in the latter group, electrophysiologic evaluation was the most elucidative from a diagnostic perspective. The ultimate goal is to obtain a sufficiently strong correlation between syncopal symptoms and detected abnormalities to permit an accurate assessment of prognosis and to develop an effective treatment plan.
  
  
  CONCLUSIONS
  It is very important to establish the etiology of syncope for optimal management of patients and it is therefore possible to control the symptoms in the majority of them. The patients who present syncope require a complete history and a physical examination for an appropriate workup to be initiated. Tilt-table testing was the most accurate for the diagnosis of vasodepressor syncope while electrophysiologic testing provides an accurate method for assessing the etiology of tachyarrhythmic syncope.
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz, Carnaxide.
authors.forename: A
authors.initials: A
authors.lastname: Mesquita
authors.forename: G
authors.initials: G
authors.lastname: Caires
authors.forename: L
authors.initials: L
authors.lastname: Parreira
authors.forename: J
authors.initials: J
authors.lastname: Ferreira
authors.forename: P
authors.initials: P
authors.lastname: Adragão
authors.forename: F
authors.initials: F
authors.lastname: Morgado
authors.forename: D
authors.initials: D
authors.lastname: Bonhorst
authors.forename: R
authors.initials: R
authors.lastname: Seabra-Gomes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000150:complications; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013575:Syncope / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy
vernacular_title: Papel dos exames auxiliares de diagnóstico no esclarecimento etiológico da síncope--experiência de uma consulta de arritmologia.