title: Syncope in patients with right ventricle outflow tract premature beats and no apparent structural cardiopathy.
abstract: OBJECTIVE
  Study the prevalence of neurocardiogenic etiology in patients with unexplained syncope and ventricular premature beats, with right ventricle outflow tract morphology (RVOT) and no apparent structural cardiopathy.
  
  
  METHODS
  Ninety patients (66 women, mean age 40.2 +/- 16.95 years of age) with monomorphic premature beats originated at RVOT were evaluated prospectively. Fifty-four patients reported syncopes or near-syncopes associated to palpitations or not; twenty-seven presented palpitations with no pre-syncope or syncope, and nine were asymptomatic. All patients were submitted to echocardiogram, high resolution ECG and cardiac MRI to rule out structural cardiopathy, to exertion test to rule out adrenergic dependent ventricular tachycardia, and ECG prolonged outpatient monitoring (Holter and symptomatic events monitor) to correlate symptoms and ventricular arrhythmias. Investigation on the susceptibility to neurocardiogenic syncope was evaluated by Tilt Table Test (TTT). Groups were compared regarding gender, age, premature beats frequency and complexity, at exertion or not, TTT results and clinical course.
  
  
  RESULTS
  In the syncope and pre-syncope groups, TTT was positive for 38% of cases, and in groups with palpitations and assymptomatics, it was positive for 11% (p = 0.0257). After recommendations and treatment of neurocardiogenic syncope, 85% of syncope and pre-syncope patients and positive TTT was asymptomatic along the 40-month follow-up. Two patients with syncope and negative TTT presented spontaneous, sustained ventricular tachycardia during clinic course.
  
  
  CONCLUSIONS
  The prevalence of neurocardiogenic syncope in patients with idiopathic RVOT premature beats is high. Patients with recurrent, unexplained syncope and idiopathic VE must be kept under investigation.
authors.affiliation: Instituto do Coração do Hospital das Clínicas, FM, USP, São Paulo, SP, Brazil.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Ludovice
authors.forename: Denise Tessariol
authors.initials: DT
authors.lastname: Hachul
authors.forename: Francisco Carlos
authors.initials: FC
authors.lastname: Darrieux
authors.forename: Silvana Cardoso
authors.initials: SC
authors.lastname: Bastos
authors.forename: Eduardo Argentino
authors.initials: EA
authors.lastname: Sosa
authors.forename: Mauricio Ibrahim
authors.initials: MI
authors.lastname: Scanavacca
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D005117:Cardiac Complexes, Premature / Q000503:physiopathology*; D002648:Child; D015716:Electrocardiography, Ambulatory / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013575:Syncope / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology