A simple pacing method to diagnose postero-anterior (clockwise) cavo-tricuspid isthmus block after radiofrequency ablation.

Aims: Bidirectional block of the cavo-tricuspid isthmus (CTI) is a widely accepted endpoint for typical atrial flutter ablation, but its evaluation may be difficult, especially in the postero-anterior (clockwise) direction. The main goal was to evaluate pacing at the septal edge of the ablation line as an indicator of clockwise CTI block and as a predictor for flutter recurrence.

Methods And Results: In 94 patients undergoing flutter ablation, CTI block in the antero-posterior (counterclockwise) direction was determined by differential pacing from several levels of the anterior right atrial (RA).

Electroanatomic study of the left atrial insertion of an epicardial accessory pathway integrating the coronary sinus.

Endocardial electro-anatomic reconstruction of the left atrium and activation mapping defined a very large atrial accessory pathway insertion with a previously failed ablation attempt. Radiofrequency application inside the coronary sinus (CS), at a site with a sharp electrogram bridging atrial and ventricular electrograms abolished pathway conduction. The myocardium in the venous branches of the CS appeared to be responsible for this extraordinary atrial insertion area.

Atrial activation occurring immediately after successful cardioversion of atrial fibrillation.

Background And Objective: Electrical defibrillation is very effective in interrupting atrial fibrillation (AF). However, its mechanism is not completely understood. We report our observations in patients subjected to external electriocardioversion (ECV) of atrial fibrillation and contrast them with recent theories about defibrillation mechanism.

[The superior vena cava as a site of ectopic foci in atrial fibrillation].

Radiofrequency catheter ablation of ectopic foci that trigger atrial fibrillation has been established as a curative method for patients with symptomatic paroxysmal atrial fibrillation. Although the majority of these foci are located in and around the pulmonary veins, other less common locations have been identified. Recognition that foci can lie outside the pulmonary veins is important for ensuring therapeutic success.

Pyoderma gangrenosum complicating pacemaker implant.

A 70-year-old lady with diabetes and monoclonal gammopathy underwent pacemaker implant for 2:1 atrioventricular block. Within 7 days, a painful, infiltrating, necrotic lesion involved the implant area. Biopsy was compatible with pyoderma gangrenosum and corticosteroid treatment led to healing in 3 weeks.

[Atrial flutter: an update].

Invasive electrophysiologic studies have changed the clinical outlook for patients with atrial flutter. Recognition of the reentrant circuit responsible for typical atrial flutter has led to the development of catheter ablation techniques that can prevent recurrence in >90% of cases. In addition, general understanding of atrial tachycardias has changed radically, such that ECG-based classifications are now obsolete.

Atrial activation mapping in sinus rhythm in the clinical electrophysiology laboratory: observations during Bachmann's bundle block.

Introduction: The high posterolateral right atrium (RA) is considered the "sinus node area," but we lack information on endocardial atrial activation in sinus rhythm. We studied RA and left atrial (LA) endocardial activation in the electrophysiology laboratory.

Methods And Results: Thirty-five patients (21 men) aged 47 +/- 16.

Atypical flutter: a review.

Understanding of typical flutter circuits led the way to the study of other forms of macroreentrant tachycardias of the atria, and to their treatment by catheter ablation. It has become evident that the ECG classification of atrial flutter and atrial tachycardia by a rate cutoff and the presence or absence of isoelectric baselines between atrial deflections is not a valid indicator of tachycardia mechanism. Macroreentrant circuits where activation rotates around large obstacles are the most common arrhythmias found in patients with atypical forms of flutter or atrial tachycardia, especially after surgery for congenital heart disease, however, focal mechanisms can also be found.

Severe mitral regurgitation with right ventricular pacing, successfully treated with left ventricular pacing.

A case of severe mitral regurgitation with refractory heart failure, after atrioventricular junction ablation and pacemaker implant, was solved with left ventricular pacing. Mitral regurgitation was related to a change in segmental left ventricular motion during right ventricular pacing.

[Electrophysiological and clinical characterization of left atrial macroreentrant tachycardia].

Background And Objective: We are reporting the characteristics of 9 patients with left atrial macroreentrant tachycardia, an arrhythmia not well studied in man.

Patients And Method: Mean age was 60 years and 7 were men. Tachycardia was spontaneous in 6 and induced in 3.