Atrial distension, rather than change in intra-atrial pressure, has been suggested as a principal mediator of release of atrial natriuretic factor (ANF). During cardiac tamponade, atrial pressures rise whereas transmural pressures and atrial stretch may not be affected. The roles of atrial pressure and atrial distension were investigated in six open-chest dogs subjected to cardiac tamponade and...

INTRODUCTION Acutely, when left atrial ablation is performed during atrial fibrillation (AF), the AF may persist and require cardioversion, or it may convert to sinus rhythm or to atrial tachycardia/flutter. The prevalence of these acute outcomes has not been described. METHODS AND RESULTS Left atrial ablation, usually including encirclement of the pulmonary veins, was performed during AF in ...

The mechanisms of atrial fibrillation relate to the presence of random reentry involving multiple interatrial circuits. Triggers for development of atrial fibrillation include rapidly discharging atrial foci (mainly from pulmonary veins) or degeneration of atrial flutter or atrial tachycardia into fibrillation. Therapy for control of atrial fibrillation includes drugs, atrial pacing for those w...

BACKGROUND In animal studies, atrial fibrillation has been shown to shorten the atrial refractory period and impair its rate adaptation. However, little is known about the effects of chronic atrial fibrillation on atrial electrophysiology and its recovery course in humans. METHODS AND RESULTS Nineteen patients, mean age 64 +/- 14 years, with chronic atrial fibrillation of more than six months...

BACKGROUND Information about electrophysiological characteristics and radiofrequency ablation of intra-atrial reentrant tachycardia has not been reported before. We proposed that induction and termination of intra-atrial reentrant tachycardia by atrial extrastimuli or rapid atrial pacing and resetting the response pattern by atrial extrastimuli during intra-atrial reentrant tachycardia could en...

Atrial fibrillation is more common in conditions with elevated atrial pressure and can be induced experimentally with acute increases in atrial pressure. We examined the effect of increased atrial pressure with and without pericardial constraint to better separate the effects of increased pressure and atrial stretch. In Langendorff-perfused rabbit hearts with intact pericardium, after ligating ...

OBJECTIVE To assess the effect of adding propafenone to atrial overdrive for the prevention of atrial arrhythmia episodes in patients with DDD pacemakers. DESIGN 22 patients (8 female, 14 male, mean (SD) age 67 (9) years, range 48 to 77) with DDD pacemakers and frequent paroxysmal atrial arrhythmia episodes were evaluated in a randomised crossover study. SETTING University hospital. METHO...

BACKGROUND Analysis of high gain, signal-averaged (SA) ECG is an accepted method evaluating abnormalities of atrial repolarization--the presence of late potentials (ALP)--predictive for atrial arrhythmias. Recently it has been proven that the location of atrial leads has an influence on atrial activation and modifies the risk of atrial arrhythmias. The aim of our study was to estimate the effec...

OBJECTIVE We prospectively tested the hypothesis that atrial enlargement and increased level of atrial natriuretic peptide, N-terminal atrial natriuretic peptide and brain natriuretic peptide would predict atrial fibrillation after coronary artery bypass grafting. METHODS Eighty-eight elective coronary artery bypass grafting patients had preoperative echocardiographic assessment. The level of...

OBJECTIVE To describe the electrocardiographic and electrophysiological findings of new atrial flutter developing in patients taking class IC antiarrhythmic drugs for recurrent atrial fibrillation, and to report the long term results of right atrial isthmus ablation in relation to the ECG pattern of spontaneous atrial flutter. DESIGN Retrospective analysis. SETTING Tertiary care academic ho...