Atrial Fibrillation and Sudden Death: Are they linked? Mariell Jessup MD Professor of Medicine University of Pennsylvania Philadelphia, Pennsylvania

Cardiology Clinics 2009; 27:151 AF doubles in incidence with each decade of age, afflicting up to 10% of patients older than the age of 80 years. Subanalyses of major primary and secondary prevention ICD trials have all shown preserved efficacy of ICDs in the elderly. Heart failure (HF) is one of the most significant factors for patients at risk for SCD and AF. AF can be found in up to 40% of patients who have symptomatic HF.

AF affects more than 2 million Americans and 6 million in Europe. AF in the ICD population leads to special problems, such as the delivery of inappropriate ICD therapies. Offers special opportunities for assessing therapy effectiveness by direct interrogation of AF burden. Many of the factors that predispose people to AF are the same risk factors that put them at risk for SCD.

Among patients with HF in general, AF has not been consistently shown to increase mortality. Specific data on the additional risk for AF in patients with ICDs are limited and conflicting. Inappropriate shocks comprise 12% to 30% of all shock therapies delivered. Supraventricular tachyarrhythmia is the most common independent predictor of inappropriate shocks, and of these, AF is the most frequent type (44%–51%).

AF is sometimes considered as a trigger for ventricular arrhythmia. Multiple reports have consistently identified an association between AF and appropriate ICD therapy.

Atrial Fibrillation and Sudden Death: Are they linked? The same risk factors that lead to AF cause SCD. AF may confer a higher independent mortality. The presence of AF in ICD patients is ominous. Treatment of AF may prompt sudden death. –Especially with anti-arrhythmics or ablation. Sleep apnea is a special link of AF and SCD Genetic abnormalities and special sub-groups will become increasingly important in the future.