Characteristics of the ventricular insertion sites of accessory pathways with anterograde decremental conduction properties

Accessory pathways (APs) with anterograde decremental conduction properties referred to as Mahaim fibers have recently been recognized as originating from the right lateral atrium. Little information is available about their distal insertion. The purpose of this study was to determine the different...

Full description

Saved in:
Bibliographic Details
Published in:Circulation (New York, N.Y.) N.Y.), 1995-02, Vol.91 (4), p.1077-1085
Main Authors: HAÏSSAGUERRE, M, CAUCHEMEZ, B, MARCUS, F, LE METAYER, P, LAURIBE, P, POQUET, F, GENCEL, L, CLEMENTY, J
Format: Article
Language:English
Subjects:
Adult
Atrial Fibrillation - diagnosis
Atrial Fibrillation - physiopathology
Atrial Fibrillation - surgery
Biological and medical sciences
Bundle-Branch Block - physiopathology
Cardiac dysrhythmias
Cardiac Pacing, Artificial
Cardiology. Vascular system
Catheter Ablation
Electrocardiography
Female
Heart
Heart Conduction System - pathology
Heart Conduction System - physiopathology
Heart Conduction System - surgery
Humans
Male
Medical sciences
Pre-Excitation, Mahaim-Type - diagnosis
Pre-Excitation, Mahaim-Type - physiopathology
Pre-Excitation, Mahaim-Type - surgery
Tachycardia, Paroxysmal - diagnosis
Tachycardia, Paroxysmal - physiopathology
Tachycardia, Paroxysmal - surgery
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Accessory pathways (APs) with anterograde decremental conduction properties referred to as Mahaim fibers have recently been recognized as originating from the right lateral atrium. Little information is available about their distal insertion. The purpose of this study was to determine the different kinds of APs involved and the characteristics of their distal insertion site. Twenty-one patients (mean age, 28 +/- 13 years) with reciprocating tachycardia or atrial fibrillation were studied. Right-sided atrial and/or ventricular endocardial mapping during tachycardia identified different types of APs. (1) Seventeen patients had long APs originating from the right lateral atrium and coursing several centimeters to the right ventricle. In 10 patients, the AP terminated in or close to the right bundle-branch system (atriofascicular AP) and in 7, the AP terminated in the anterior right ventricle (atrioventricular AP). Patients with atriofascicular APs had narrower QRS complexes (133 +/- 10 versus 165 +/- 26 milliseconds, P = .02) and narrower initial r wave in leads V2 through V4 during maximal preexcitation than patients with atrioventricular APs. In addition, they had earlier His-bundle and right bundle-branch retrograde activation, ie, shorter V-His (16 +/- 5 versus 37 +/- 9 milliseconds, P < .01) and V-right bundle intervals (3 +/- 5 versus 25 +/- 6 milliseconds, P < .01). In 6 patients, minimal preexcitation not readily apparent was present in sinus rhythm despite the appearance of a narrow QRS complex. A wide distal insertion site of 0.5 to 2 cm in diameter consistent with arborization of the AP was found in 10 patients. The distal application of radiofrequency current produced a change in the preexcitation pattern in 4 patients and ablated the AP in 2 patients. In the other patients, radiofrequency current was applied more proximally and successfully ablated the AP bundle (n = 9) or AP proximal insertion (n = 6). No recurrence was observed during a follow-up period of 12 +/- 10 months. (2) Four patients had short paratricuspid atrioventricular APs; in one, the decremental conduction property was acquired as demonstrated by two electrophysiological studies performed 7 years apart. Radiofrequency ablation was successfully accomplished in all 4 patients at the tricuspid annulus. Different types of APs account for tachycardias previously called Mahaim fibers. Long and short atrioventricular APs are observed in 81% and 19%, respectively. Long APs often have a d
ISSN:0009-7322
1524-4539
DOI:10.1161/01.CIR.91.4.1077