Atrial fibrillation and sudden cardiac death, a nested case-control study looking at cardiac pathology

Atrial fibrillation (AF) is the most common heart rhythm disorder with an estimated prevalence of 2-4% in adults. AF is a recognised risk factor for sudden cardiac death (SCD) and has been associated with most cardiac diseases. As the atria enlarge the risk of developing AF increases. We sought to establish the cardiac diseases associated with AF from a cohort of individuals who experienced SCD from a national referral centre for SCD. Cases were randomly age and sex matched to individuals without AF who experienced SCD. Characteristics and cardiac diseases were compared between cohorts. Sudden arrhythmic death syndrome (SADS), where no cardiac pathology was found was significantly underrepresented in AF compared to controls (46 vs 27, p = 0.01). Cardiomyopathy was more common in AF compared to controls (32 vs 15, p = 0.01). Ischemic Heart Disease and other cardiac pathologies were similar in prevalence across AF and controls (22 vs 20, p = 0.86; 27 vs 27, p = 0.99). AF is a concerning development in cardiomyopathy and increases the risk of SCD. Heart failure can lead to an enlargement of the atria which is in turn linked to an elevated risk of AF. Aggressive medical treatment of heart failure is important to prevent cavity dilation and the development of AF. AF is a concerning development in cardiomyopathy and may indicate an increase in the risk of SCD as we observed cardiomyopathy and AF more commonly in younger individuals.