The atria are highly complex multidimensional structures composed of a heterogeneous branching network of subendocardial muscular bundles. The relief of the inner part of the right atrium includes the crista terminalis as well as multiple pectinate muscles that bridge the thinner atrial free walls and appendages. However, a handful of studies have focused attention on the role of the naturally ...

BACKGROUND Previous studies report that CHADS2 and CHA2DS2-VASc risk scores have similar discriminating ability (C statistic ∼0.6). Recently a clinically based risk score, the ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation) study risk score, was developed and validated. OBJECTIVES This study compared predictive ability of CHA2DS2-VASc and CHADS2 ischemic stroke risk scores wit...

Atrial fibrillation is a common cardiac arrhythmia in which there is an irregular heartbeat. This paper develops a theoretical model for the intervals between successive heartbeats during atrial fibrillation based on the following ideas. There is an irregular pattern of activation of the upper chambers ~atria! of the heart. Excitation travels from the atria through the specialized conducting ti...

There is a close interrelationship between atrial fibrillation (AF) and atrial flutter (AFL). Atrial fibrillation of variable duration precedes the onset of AFL in almost all instances; during AF, the functional components needed to complete the AFL re-entrant circuit, principally a line of block (LoB) between the vena cavae, are formed; if this LoB does not form, classical AFL does not develop...

Introduction Atrial fibrillation (AF) is the most common arrhythmia in humans. Its maintenance is thought to be due to multiple wavelets reentry occurring in both atria [1]. Previous studies have demonstrated the feasibility and efficacy of cryoablation to create lesions in both atria [2] and on the posterior wall of the left atrium [3], connecting the four pulmonary veins and the mitral annulu...

Copyright © 2009 American Heart Association. All rights reserved. Print ISSN: 0009-7322. Online 72514 Circulation is published by the American Heart Association. 7272 Greenville Avenue, Dallas, TX DOI: 10.1161/CIRCULATIONAHA.108.816082 2009;119;1363-1369; originally published online Mar 2, 2009; Circulation Investigators Pomernacki, Leila Borowsky, Daniel E. Singer and for the ATRIA Study Alan ...

Wolff-Parkinson-White (WPW) syndrome is caused by an accessory pathway that communicates between the atria and ventricles known as Bundle of Kent. The development atrial fibrillation, can result in impulses all being conducted via a sinister, board complex, irregular tachycardia, with varying QRS morphology (known pre-excited fibrillation) Adenosine potent atrioventricular node blocker, which b...

OBJECTIVES The objective of this study was to compare the predictive performance of bleeding risk-estimation tools in a cohort of patients with atrial fibrillation (AF) undergoing anticoagulation. BACKGROUND Three bleeding risk-prediction schemes have been derived for and validated in patients with AF: HEMORR(2)HAGES (Hepatic or Renal Disease, Ethanol Abuse, Malignancy, Older Age, Reduced Pla...

Atrial fibrillation (AF) usually manifests as reentrant circuits propagating through the whole atria creating chaotic activation patterns. Little is yet known about how differences in electrophysiological and ionic properties between patients modulate reentrant patterns in AF. The goal of this study is to quantify how variability in action potential duration (APD) at different stages of repolar...