Síncope em pacientes com extra-sístoles de via de saída de ventrículo direito e sem cardiopatia estrutural aparente

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 (54) patients reported syncopes or near-syncopes associated to palpitations or not; twenty-seven (27) presented palpitations with no pre-syncope or syncope, and nine (9) 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. Conclusion: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. VPBs with right ventricle outflow tract morphology (RVOT) at ECG are frequently seen. Those patients may present recurring near-syncopes and syncopes, and most times it is not possible to establish a correlation between rhythm changes and the symptoms during outpatient ECG monitoring.Recurrent syncope is an alarming symptom. Syncope etiology is many times erroneously associated to that arrhythmia in individuals irrespective of the clinical correlation between symptoms and electrocardiographic findings.The neurocardiogenic syncope is the most common syncope etiology in individuals without apparent cardiopathy. It has not been reported a higher cardiovascular risk in that group of patients when compared to the normal population 3,4 . Diagnosis is reached by suggestive history, by the nondemonstration of arrhythmic causes and by positive TTT.The purpose of this study was to investigate the prevalence of neurocardiogenic syncope in patients with idiopathic RVOT premature beats. MethodsNinety patients were investigated prospectively: mean age 40.2 ± 16.95 (ranging between 7 and 79 years of age), being 66 of them females. Inclusion criteria included: the presence of idiopathic RVOT premature beats, characterized by left bundle branch bloc...