Recent studies have demonstrated that fibrillatory rhythms are not random phenomena but have definable patterns. However, standard mapping techniques may have limitations in their ability to identify the organization of fibrillation. The purpose of this study was to develop and apply a method, "ensemble vector mapping," for characterizing the spatiotemporal organization of fibrillation. Ventric...

BACKGROUND The occurrence of atrial fibrillation after ablation of type I atrial flutter remains an important clinical problem. To gain further insight into the pathogenesis and significance of postablation atrial fibrillation, we examined the time to onset, determinants, and clinical course of atrial fibrillation after ablation of type I flutter in a large patient cohort. METHODS AND RESULTS...

AIMS To characterize the nature and timing of atrial ectopics preceding clinical episodes of paroxysmal atrial fibrillation. METHODS AND RESULTS Holter recordings (n= 177, 60 patients, 58% male, mean age 61.7 +/- 11.5 years) were performed on patients with paroxysmal atrial fibrillation. These were subjected to standard analysis and recordings containing atrial fibrillation episodes suitable ...

OBJECTIVE Diabetes has long been recognized as a risk factor for atrial fibrillation, but its independent contribution to atrial fibrillation has not been fully evaluated. We sought to compare the prevalence and incidence of atrial fibrillation in age- and sex-matched patients with and without type 2 diabetes. RESEARCH DESIGN AND METHODS Using an observational cohort design, we selected 10,21...

Na(+) and K(+) channel-blocking drugs have anti- and proarrhythmic effects. Their effects during fibrillation, however, remain poorly understood. We used computer simulation of a two-dimensional (2-D) structurally normal tissue model with phase I of the Luo-Rudy action potential model to study the effects of Na(+) and K(+) channel blockade on vulnerability to and termination of reentry in simul...

BACKGROUND Atrial fibrillation is the most common complication after myocardial revascularization, and it increases morbidity/mortality. OBJECTIVE The purpose of this prospective randomized study was to test the hypothesis that temporary biatrial pacing is effective in reducing the incidence of postoperative atrial fibrillation after myocardial revascularization. METHODS Ninety-eight non-co...

Incidence, determinants, and outcome of atrial fibrillation in hypertensive subjects are incompletely known. We followed for up to 16 years 2482 initially untreated subjects with essential hypertension. At entry, all subjects were in sinus rhythm. Subjects with valvular heart disease, coronary artery disease, preexcitation syndrome, thyroid disorders, or lung disease were excluded. During follo...

OBJECTIVE To determine the type of atrial fibrillation induced by use of 2 pacing protocols during fentanyl and pentobarbital anesthesia before and after administration of atropine and to determine the organization of electrical activity in the left and right atria during atrial fibrillation in German Shepherd Dogs. ANIMALS 7 German Shepherd Dogs. PROCEDURES Extrastimulus and pacedown proto...

INTRODUCTION Postoperative atrial fibrillation is the most common arrhythmia in cardiac surgery, its incidence range between 20% and 40%. OBJECTIVE Quantify the occurrence of stroke and acute renal insufficiency after myocardial revascularization surgery in patients who had atrial fibrillation postoperatively. METHODS Cohort longitudinal bidirectional study, performed at Portuguese Benefice...