A unique preexcitation pattern related to an atypical anteroseptal accessory pathway

An Unusual Accessory Pathway: Anteroseptal to Ventricular Outflow Region Connection

Accessory pathways are typically located along the left or right atrioventricular junction. Distinct ventricular pre-excitation patterns determined by surface electrocardiography can provide reasonable pathway localization prior to invasive mapping and catheter ablation. We report an accessory pathway producing an unusual electrocardiographic appearance suggestive of ventricular outflow region pre-excitation. Pacing maneuvers and standard intracardiac recordings confirmed an atrial insertion immediately adjacent to the atrioventricular (AV) node and supported a ventricular insertion at the outflow tract region well away from the AV junction. The elimination of pathway conduction was achieved with radiofrequency (RF) energy at the atrial insertion after successful ice mapping excluded AV block at the target site. This is the second such pathway observed at our institution over a 20-year period.

A nodoventricular fiber associated with dual AV nodal conduction, AV nodal reentrant tachycardia, and anterior location of the slow AV nodal pathway

We present a case of a patient with a nodoventricular tract, associated with dual AV nodal conduction and AV nodal reentrant tachycardia, and an anteroseptal location of the slow AV nodal pathway. The remarkable feature of this case is the site of successful ablation, in the anteroseptum just anterior and superior to the His bundle, where both preexcitation and dual AV nodal physiology were abolished.

Supraventricular tachycardias: the role of surgery

Because of its high efficacy and low morbidity radiofrequency energy catheter ablation techniques have toppled the hierarchy of choice in the electrophysiological intervention armamentum. This review assesses current role of surgery and its foreseeable future. Most accessory AV pathways can be attained by endocardial manipulation and ablated. Surgical dissection of accessory pathways on the beating heart had documented that most pathways were paraannular, although right-sided pathways may be distant to the annulus. Results of accessory pathway ablation have shown that right-sided pathways are difficult to approach and ablate. Surgical ablation may currently be considered after failed catheter ablation. AV nodal modification using catheter ablation also yields excellent results. Radiofrequency energy creates a discrete lesion associated with discrete electrophysiological alteration. Surgical dissection is associated with more diffuse and extensive anatomical and electrophysiological changes and is no longer used even after failed catheter ablation. The arrhythmogenic anatomical substrate associated with atrial flutter is not yet well delineated in the coronary sinus os region. How to extend tissue modification for uniform success here is not yet known. Further surgical approach combined with extensive intraoperative cardiac mapping may ultimately prove a valuable guide for subsequent catheter technique. Atrial fibrillation is the last surgical frontier unchallenged by catheter techniques. Arrhythmogenic anatomical substrate is diffuse spreading over the entire atrial myocardium without a discrete target. The associated pathology is diffuse, severe, and progressive and present even in the so-called lone atrial fibrillation. Progression of underlying pathology can nullify the best designed surgical rationale in terms of sinus node chronotropic function, and atrial contractility. Currently used surgical techniques, i.e., the corridor and the Maze operations, have contributed to a better selection of patients. Surgery is still associated with significant morbidity and relative efficacy, and may be improved before becoming the electrophysiological intervention of choice for atrial fibrillation. In conclusion, atrial fibrillation is a greater surgical challenge, but has to be met with the same standard used for other supraventricular tachycardias.