Sudden arrhythmic death syndrome (SADS) causing cardiac arrest in the young- risk factors are identifiable trough preparticipation screening

Abstract Background Sudden arrhythmic death syndrome(SADS) is one of the most common post-mortem diagnoses of sudden cardiac death(SCD) in the young. Identification of preceding symptoms and risk factors could potentially prevent death. Purpose The purpose of the study was to describe incidence and phenotypes of SADS victims in a cohort of SCD in the young. Methods All cases of SCD, among 1-35 years old in Sweden during 2000-2010 have previously been registered in The Swedish SUDden cardiac Death in the Young(SUDDY) cohort, together with five controls. By review of death certificates, autopsy reports and medical records, 149 cases from the SUDDY cohort were identified as SADS victims. Demographics, prior health care contacts and ICD specific diagnoses were retrieved from national registers. Data from medical records, ECGs, death certificates and autopsy reports were analyzed to describe the phenotypes. Results SADS accounted for 22% of all SCDs among 1-35 years old during the study period. Of the SADS victims, 96 were male (64%) and median age at death was 23. SADS occurred during everyday activity in 42% of cases, in 38% during sleep or rest and in 12% during physical activity. A prior pathological ECG was found in 18% of SADS victims, with preexcitation/WPW being the most common finding, followed by long QT. Previous hospitalization or outpatient care visit within 180 days prior to death was seen in 33% of SADS victims versus 24% of controls(p=0.038). Among SADS victims, 4.2% had previously been hospitalized with a diagnosis of syncope, versus 0.41% of controls(p<0.001) and hospitalization due to convulsion occurred in 3.5% of SADS victims versus 0.14% in the control group(p<0.001). In 52% of SADS victims, any symptoms prior to death were documented. A family history of cardiac disease was documented in 13% of SADS victims, 17% had a previous psychiatric diagnosis and 11% was under treatment with psychotropic drugs. Conclusion A high prevalence of prior healthcare contacts, previous symptoms and pathological ECGs offers an opportunity to identify subjects at risk of SADS. Our findings emphasize the importance of recognizing red flags such as syncope and convulsion during preparticipation screening of young athletes. Adding an ECG to such screening increases the likelihood of identifying risk features such as preexcitation/WPW.