Early warning signs may help prevent sudden arrhythmic death syndrome

Recognizing and detecting the signs that commonly precede sudden arrhythmic death syndrome (SADS) may help to prevent premature deaths, according to research presented today at ESC Preventive Cardiology 2025, a scientific congress of the European Society of Cardiology (ESC). 

SADS has not been well evaluated despite being one of the most common underlying causes of sudden cardiac death in young people, including young athletes. We conducted an analysis of a large cohort of cases of sudden cardiac death in Sweden to describe the incidence of SADS and to characterise frequent findings that occurred before death to highlight opportunities for prevention." 

Dr. Matilda Frisk Torell, study author of Sahlgrenska Academy - University of Gothenburg, Sweden

This was a retrospective observational study of the SUDden cardiac Death in the Young (SUDDY) cohort, which included all 903 cases of sudden cardiac deaths that occurred in young people aged 1–36 years in Sweden from 2000 to 2010. Five population-based controls were assigned per case. Information was analysed from death certificates, autopsy reports, medical records, electrocardiograms (ECGs), any biological samples and parental data. 

The researchers found that SADS accounted for 22% of all sudden cardiac deaths. Almost two-thirds of SADS cases (64%) were male and the median age of death was 23 years. Previous hospitalisation or an outpatient care visit within 180 days of death was reported in 33% of SADS cases versus 24% of controls (p=0.038). Among SADS cases, 4.2% had previously been hospitalised with a diagnosis of syncope versus 0.41% in the control group (p<0.001), while hospitalisation due to a convulsion occurred in 3.5% of SADS cases versus 0.14% in controls (p<0.001). In total, 11% had previously known arrhythmic disease and 18% had a pathological ECG, with pre-excitation (premature activation of the ventricles) being the most common finding. Around half (52%) of cases experienced symptoms before death, particularly palpitations, syncope, nausea/vomiting and signs related to suffering from an infection. In total, 17% of cases had a previous psychiatric diagnosis and 11% had received psychotropic drugs. 

Dr. Frisk Torell said: "With increased knowledge of the signs and symptoms that may precede SADS, such as syncope, seizure-like episodes and pre-excitation, we may be able to identify young people at risk during healthcare visits. Our results also highlight the need for further study of psychiatric disease/treatment as risk factors for SADS and the potential for gastrointestinal symptoms and infectious diseases to act as triggers in predisposed individuals. Preparticipation screening of young athletes is an important opportunity to identify these signs and reduce the occurrence of SADS, and yet current levels of screening are low."