BACKGROUND Ventricular fusion during transient entrainment of orthodromic atrioventricular reciprocating tachycardias (OAVRT) was originally found to be absent and recently observed only with left ventricular stimulation. However, previous studies were restricted to cases with a left free wall accessory pathway. The hypothesis of the present study was that fusion is likely during resetting and ...

In case of the first possibility (AVRT), an accessory pathway is responsible for the retrograde limb of the tachycardia circuit (there is no evidence for anterograde conduction over the accessory pathway on the ECG in sinus rhythm, as show in Fig. 1b of the question). Therefore a ‘concealed’ accessory pathwaymust be present. Anterograde conduction occurs over a dual AV nodal pathway (Fig. 2, up...

Paroxysmal supraventricular tachycardia (SVT) is commonly produced by two mechanisms: atrial reentry via an A-V nodal pathway or a rapid firing ectopic focus. Studies in the experimental animal and in human beings with sustained SVT have sbown that the site for reentry appears to be the upper A-V junction. This report documents an unusual site d reentry in a patient with recurrent SVT. Progress...

OBJECTIVES This randomized prospective study sought to assess the value of slow pathway (SP) mapping and ablation guided by subthreshold stimulation (STS) in comparison with a strategy based on conventional criteria. BACKGROUND Previous studies have demonstrated that STS can be used as a highly specific and sensitive marker for successful SP ablation in the setting of atrioventricular nodal r...

Atrial fibrillation requires a trigger that initiates the arrhythmia and substrate that favors perpetuation. Cardiac mapping is necessary to locate triggers and substrate so that an ablation strategy can be optimized. The most commonly used cardiac mapping approach is isochronal or activation mapping, which aims to create a spatial model of electrical wavefront propagation. Historically, activa...

Introduction Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common regular supraventricular arrhythmia. It typically presents with rapid and regular palpitations of abrupt onset in young adults, with a female preponderance. In patients without structural heart disease, AVNRT is largely considered to have a benign course and is rarely associated with disabling symptoms, such as...

INTRODUCTION LocaLisa is a novel system for anatomical mapping. It enables an assessment of the three-dimensional position of electrodes within cardiac chambers without fluoroscopy. With this technique it may be possible to reduce radiation exposure during catheter-based ablation procedures. AIM To evaluate the efficacy and safety of ablation procedures performed using the LocaLisa mapping sy...

AIM Sub-threshold stimulation (STS) applied during atrioventricular nodal re-entrant tachycardia (AVNRT) of the common (slow-fast) type has been shown to effectively characterise target sites suitable for slow pathway (SP) ablation but has not been investigated in the setting of fast-slow and slow-slow variants. METHODS AND RESULTS Seventeen consecutive patients (52+/-16 years, 12 female) wit...

assessment after pediatric cardiac ablation: design and implementation of the Multicenter Study. Pace 2002;25:332–41. 18. Van Hare GF, Javitz H, Carmelli D, Saul JP, Tanel RE, Fischbach PS et al. Prospective assessment after pediatric cardiac ablation: demographics, medical profiles, and initial outcomes. J Cardiovasc Electrophysiol 2004;15:759–70. 19. Kugler JD, Danford DA, Deal BJ, Gillette P...