Atrial Fibrillation and Its Association With Sudden Cardiac Death

Abstract

2588CHEN LY et al. Circulation JournalOfficial Journal of the Japanese Circulation Society http://www. j-circ.or.jp are only starting to understand -SCD. We will review the evidence for an independent relationship between AF and SCD in different contexts: recipients of implantable cardioverterdefibrillators (ICDs), patients with MI, HF, or hypertension (HT), and finally, in the general population. We will also examine the determinants of SCD in patients with AF and postulate on the mechanisms underlying this novel and intriguing association. AF and Ventricular Tachyarrhythmias in Recipients of ICDsOne of the earliest lines of evidence to suggest that AF may inherently increase the incidence of ventricular tachycardia (VT) or ventricular fibrillation (VF) comes from patients who have received an ICD. In a study comprising 229 patients who received ICDs between 1995 and 1999 for secondary prevention of SCD, 19 those who had persistent AF (n=38) at the time of ICD implant experienced appropriate device therapy for recurrent ventricular tachyarrhythmias more frequently than patients who were in sinus rhythm at the time of ICD implantation (n=191) (63% vs. 38%, P=0.01). From multivariable analysis, AF was an independent predictor of both appropriate ICD therapy (relative risk 1.8; 95% confidence interval [CI] 1.2-2.9) and inappropriate device therapy (relative risk 2.3; 95% CI 1.2-4.5). Analysis of device-stored electrograms revealed a higher incidence of short-long-short cycles preceding ventricular arrhythmias in AF compared with patients in sinus trial fibrillation (AF) is the most common sustained cardiac arrhythmia, and with the aging population its prevalence is increasing over time. 1-3 Additionally, AF is associated with an increased risk of stroke, 4 heart failure (HF), 5 and death. 6-11 The Framingham Heart Study reported that AF increases the risk of death by 1.5-fold in men and 1.9-fold in women. 6 Similarly, the reported Olmsted County, Minnesota experience showed that new-onset AF doubles the risk of mortality. 7 More recently, the Women's Health Study revealed that the risk of all-cause death was doubled and cardiovascular death quadrupled by new-onset AF in initially healthy women. 8 Although the evidence for an independent association of AF with an increased risk of mortality is compelling, there are few data on the causes of death in patients with AF; the most common causes of death in the aforementioned studies were coronary artery disease (CAD) and stroke. 6,7 There is evidence from post-myocardial infarction (MI) or HF patients that AF is associated with an increased risk of sudden cardiac death (SCD). 12-14 However, SCD was not specifically reported in previous population-based studies; 6-8 hence, it is unknown whether AF increases the risk of SCD in the general population. Moreover, because AF and SCD share many common risk factors, such as HF 15,16 and CAD, 17,18 it is possible that any possible association between AF and SCD is confounded or mediated by these shared risk factors.This narrativ...

Risk and Prediction of Sudden Cardiac Death and Ventricular Arrhythmias for Patients with Atrial Fibrillation – A Nationwide Cohort Study

“…In addition, the irregular rhythm of AF may lead to short-long-short sequences which are intrinsically proarrhythmic22. Therefore, AF itself may facilitate the induction of VAs and cause SCD23.…”

Digoxin Use and Subsequent Clinical Outcomes in Patients With Atrial Fibrillation With or Without Heart Failure in the ENGAGE AF‐TIMI 48 Trial

“…SCD is the single most common cause of death among patients with AF, accounting for about a third of all deaths 23, 24, 25, 26. In a recent analysis from the ENGAGE AF‐TIMI 48 trial, the cause for SCD was unknown in most cases and an arrhythmia was documented in only a minority of SCD events (11.5%) 25.…”

Transient New-Onset Atrial Fibrillation Is Associated With Poor Clinical Outcomes in Patients With Acute Myocardial Infarction

“…Whereas previous studies have provided conflicting findings concerning the association of AF and mortality, 3,17-19 recent studies, including a meta-analysis, demonstrated that AF carried adverse prognostic implications for both in-hospital and long-term mortality rates in patients with AMI. 5,6,8,9,20, 21 Rathore et al reported that patients with NOAF during hospitalization had higher in-hospital, 30-day, and 1-year mortality rates compared with those without AF. 5 They showed that the difference in mortality rates between in hemodynamic status may influence the development of AF during AMI.…”