Multifocal atrial tachycardia, also designated "chaotic atrial tachycardia," was identified in the records of 31 patients. It was particularly noted that the arrhythmia progressed to atrial fibrillation or flutter in 17 cases (55%). Unifocal or multifocal premature atrial contractions preceded the arrhythmia in 20 cases (64%). The arrhythmia developed during an acute illness in 18 cases (58%). ...

Catheter ablation is at the forefront of the management of a range of atrial arrhythmias. In this Series paper, we discuss the underlying mechanisms and the current role of catheter ablation for the three most common atrial arrhythmias encountered in clinical practice: focal atrial tachycardia, atrial flutter, and atrial fibrillation. The mechanisms of focal atrial tachycardia and atrial flutte...

UNLABELLED We reported a 60-year-old male patient who had a paroxysmal supraventricular tachycardia with QRS duration alternans (alternation between narrow QRS and wide QRS beats) and electrical alternans, but without any cycle length alternans. In the laboratory, slow-fast atrioventricular nodal reentrant tachycardia was easily induced by an atrial extrastimulus, and the arterial pressure reco...

An unusual case of atrioventricular nodal reentrant tachycardia precipitated by ethanol ingestion is presented. Programmed atrial and ventricular stimulation failed to induce the tachycardia during control conditions or after atropine administration. This failure to induce tachycardia was related to the absence of ventriculoatrial conduction. A low-dose isoproterenol infusion allowed induction ...

Electrophysiological effects of 2 to 2.5 mg/kg iv disopyramide were studied in 10 patients with dual nodal pathways who used a slow pathway for anterograde and a fast pathway for retrograde conduction during paroxysmal supraventricular tachycardia (mean cycle length 308.5 +/- 37 ms; range 260-370 ms). Disopyramide terminated the tachycardia in six cases by production of ventriculoatrial block i...

AF ablation can be curative or reduce the symptoms of AF. However, success rates are suboptimal while procedure times can be long. Since AF ablation depends on excellent tip to tissue contact, ease of use and signal quality, a new ablation catheter (FlexAbilityTM Ablation Catheter, St Jude Medical, St Paul, MN) was designed for use during complex ablation. We report an initial case of its use d...

BACKGROUND Atrial fibrillation is the most frequent cardiac rhythm disturbance, with prevalence increasing with age. This disease is a major risk factor for ischaemic stroke. The costs resulting from atrial fibrillation are really impressive. Pharmacological agents are the first line therapy for the management of atrial fibrillation. Antiarrhythmic drugs are used to terminate arrhythmias, as ac...

A 52-year-old woman with a history of multiple episodes of paroxysmal supraventricular tachycardia underwent electrophysiologic studies and a catheter ablation procedure. The 12-lead electrocardiogram during tachycardia showed a long RP tachycardia with negative P waves in leads II, III, and aVF. At baseline, dual atrioventricular (AV) and ventriculoatrial (VA) nodal conduction was elicited by ...

UNLABELLED A young man underwent 2 catheter ablation procedures because of frequent episodes of paroxysmal supraventricular tachycardia (SVT). A left accessory pathway was ablated in the first procedure. The patient underwent the second ablation procedure due to a recurrent SVT demonstrated by 12-lead electrocardiogram two weeks after the first procedure. During the second procedure, a SVT with...

BACKGROUND Ablation of complex fractionated atrial electrograms (CFAEs) has been proposed as a strategy to improve outcomes in atrial fibrillation (AF) catheter ablation, but the use of this technique remains contentious. We aimed to assess the impact of CFAE ablation in addition to pulmonary vein isolation (PVI) in patients undergoing ablation for AF. METHODS AND RESULTS We performed a rando...