Surgical technique and the mechanism of atrial tachycardia late after open heart surgery.

Introduction: Diverse atrial tachycardias (ATs) can develop after open heart surgery. The aim of our study was to examine the determinants of the mechanism of postoperative AT.

Methods And Results: One hundred patients with AT occurring at least 3 months after open heart surgery were studied.

Electrogram analysis at the His bundle region and the proximal coronary sinus as a tool to predict left atrial origin of focal atrial tachycardias.

Aims: Early activation at the His bundle (HB) region or proximal coronary sinus (CS) during focal atrial tachycardias (FATs) often necessitates biatrial mapping. Analysis of CS electrograms (EGMs) consisting of a near-field (N) component from CS musculature and a far-field (F) component from left atrial (LA) myocardium can uncover LA activation preceding right atrial (RA) activation. A similar pattern might be observed at the HB.

Ventricular location of a part of the right atrial isthmus after tricuspid valve replacement for Ebstein's anomaly: a challenge for atrial flutter ablation.

We report the case of a patient with atrial flutter late after tricuspid valve replacement for Ebstein's anomaly. Computed tomographic angiography revealed that coronary sinus ostium and part of the right atrial isthmus were located on the ventricular side of the valve ring due to the specific surgical approach in this condition. Based on the results of electroanatomic mapping and entrainment, the arrhythmia was found to be cavotricuspid isthmus dependent clockwise atrial flutter.

A simple algorithm for defining the mechanism and the chamber of origin in atrial tachycardias.

Introduction: Although macroreentrant atrial tachycardia (MRAT) and focal atrial tachycardia (FAT) can be successfully cured by catheter ablation, the proper diagnosis and treatment of these arrhythmias can still be challenging.

Aim: The objective of this study is to develop an algorithm allowing rapid diagnosis of the mechanism and the chamber of origin of atrial tachycardia based on intracardiac catheter recordings from the right atrium and the coronary sinus (CS).

Methods: A 2-stepped algorithm was designed: (1) The time of biatrial activation expressed as a percentage of the tachycardia cycle length served to discriminate FAT from MRAT.