More than one-third of young people who died from sudden arrhythmic death syndrome had health care visits within 6 months before their death, according to a nationwide Swedish study.
Sudden arrhythmic death syndrome (SADS) accounted for 22% of all sudden cardiac deaths among patients aged 1 to 35 years in Sweden between 2000 and 2010, wrote Matilda Frisk Torell, PhD, of the University of Gothenburg, and colleagues.
Within 180 days before death, 34% of SADS victims had hospital or outpatient visits compared with 23% of controls. Health care visits for syncope were 20 times more common among SADS victims (4% vs 0.2%), and visits for seizures or convulsions occurred 10 times more frequently (4% vs 0.4%).
Using the national Sudden Cardiac Death in the Young (SUDDY) cohort, investigators analyzed registry data, autopsy findings, electrocardiograms (ECGs), and medical records from 149 confirmed SADS cases and 1,475 matched controls. The median age at death was 23 years, and 65% of patients were male. Preceding symptoms were documented in 52% of cases—most commonly, infection (9%), nausea or vomiting (7%), syncope (7%), and palpitations (7%).
ECG records were available for 45% of patients, and 44% of those showed pathological histories, most often preexcitation or prolonged QT intervals. Many of these findings were recorded during routine evaluations, such as military conscription.
Psychiatric diagnoses were recorded in 17% and psychotropic drug use in 11% of patients, suggesting a potential link between psychiatric illness, medication use, and arrhythmic risk. Infection and gastrointestinal symptoms within 24 hours before death were identified as possible arrhythmic triggers in susceptible patients.
“These seizures may reflect arrhythmic syncope rather than epilepsy, emphasizing the need to include ECG in seizure workups,” wrote the investigators. “Sudden arrhythmic death syndrome is one of the most common post-mortem diagnoses in the young suffering sudden cardiac death. Phenotypic characterization may facilitate prevention."
The study was supported by grants from the Swedish Society of Medicine, Norrbotten County Council, the Swedish Research Council (2020-01947), Uppsala University Hospital, Uppsala University, and the Region of Western Sweden (ALFGBG-720691). The authors reported no additional conflicts of interest.