Primary Cardiac Electrical Diseases: Baseline and Retrospective Outcomes of a Multicenter Registry from Thailand

Objective: Primary cardiac electrical diseases are the leading cause of sudden cardiac arrest in patients with apparently normal structured heart. The purpose of this study was to assess the distribution of primary cardiac electrical diseases, as well as to assess the prognosis and predictive factors for future ventricular arrhythmia in Thai patients. Materials and Methods: Patients with primary cardiac electrical diseases who came for clinic visit at Siriraj Hospital, Buddhachinarat hospital, and Chonburi hospital were enrolled. History was acquired from interview and medical record. Results: There were 120 patients in the study. The most prevalent primary cardiac electrical disease was Brugada syndrome. Sixty nine patients experienced prior sudden cardiac death episode and all of the patient in this group had ICD implanted. None of the patient with ICD died after a median follow up of 8.59+5.01 years. Recurrent ventricular arrythmia rate was 47.8%. Among patients who had ICD implanted for primary prevention, none had sudden cardiac arrest/ new ventricular arrythmia episode detected. The only predictor of future lethal arrythmia is history of prior sudden cardiac arrest. Conclusion: Brugada syndrome is the most common etiologic cause of primary cardiac electrical disease in Thailand. ICD is extremely effective for secondary prevention of sudden cardiac arrest.