Inducibility of Atrial Flutter in Patients With Atrioventricular Nodal Reentrant Tachycardia

Abstract

revious studies have shown that typical atrial flutter (AFL) is caused by a reentrant circuit confined to the right atrium. 1,2 Percutaneous catheter mapping studies have shown that the reentrant circuit includes an area of slow conduction bounded on the lateral side by the septal leaflet of the tricuspid valve and the inferior vena cava (lateral isthmus) and on the medial side by the Eustachian valve/ridge and the septal leaflet of the tricuspid valve (medial isthmus) and the coronary sinus ostium and the septal leaflet of the tricuspid valve (septal isthmus). 1-5 Typical atrioventricular nodal reentrant tachycardia (AVNRT) has a dual atrioventricular (AV) nodal pathway physiology and can be cured by radiofrequency catheter ablation (RFCA). The "slow pathway" is thought to have a predominantly posterior -inferior location between the coronary sinus ostium and the septal leaflet of the tricuspid valve, and the "fast pathway" allegedly starts in the anterior -superior portion of the interatrial septum. [6][7][8][9][10] On the basis of a postmortem study, Inoue and Becker reported that the human compact AV node contains rightward and leftward posterior extensions, with the rightward extension close to the tricuspid annulus. They concluded that these extensions are involved in "slow pathway" conduction 11 (Fig 1). Furthermore, we recently showed by 3-dimensional reconstruction Circulation Journal Vol.70, September 2006from intracardiac ultrasonographic images that the coronary sinus is significantly larger in patients with AVNRT than in those without. 12 If the same area is critical for AVNRT and AFL, AFL might be inducible in patients with AVNRT. Therefore, the purpose of this study was to evaluate the inducibility of AFL in patients with AVNRT and to determine if the inducibility of AFL is altered by RFCA of the slow pathway of the AVNRT circuit. Methods SubjectsThe subjects of the study were 170 consecutive Japanese patients (80 men, 90 women; mean age 49±16 years) referred to Nihon University Hospital for RFCA of supraventricular tachycardia: 71 patients with inducible AVNRT and 99 control patients consisting of 14 patients with atrial tachycardia, 60 patients with manifest Wolff-ParkinsonWhite (WPW) syndrome and 25 patients with concealed WPW syndrome. No patient had a history of spontaneous AFL prior to the electrophysiological study. Age, sex and body surface area in the AVNRT group and in the group of patients with other types of supraventricular tachycardia are detailed in Table 1. No patient had structural heart disease. Each patient completed a signed consent form for participation in the study and ablation therapy. Twenty four patients with clinical history of AFL (21 men, mean age 67.0±9.2 years) were also included in this study to compare the cycle length (CL) of the AFL. Electrophysiologic TestingIn all patients, antiarrhythmic drug therapy was discon- Background Previous studies have shown that both atrioventricular nodal reentrant tachycardia (AVNRT) and atrial flutter (AFL) have an area of slow co...

Electrophysiologic and Anatomical Characteristics of the Right Atrial Posterior Wall in Patients With and Without Atrial Flutter Analysis by Intracardiac Echocardiography

“…In all patients, rapid RA pacing from the CS os and mid-free wall was performed to determine the inducibility of AFL. 19 An A20 catheter was positioned at the posterior or posterolateral RA site at which DPs or fractionated potentials (FPs) were apparently recorded along the catheter during rapid RA pacing from the CS os in patients without AFL and during AFL in patients with AFL. Endocardial bipolar electrograms were recorded with a bandpass filter of 30-500 Hz simultaneously with the 12-lead ECG, His bundle electrograms and CS electrograms, and stored digitally on a CardioLab System (Prucka Engineering, Inc, Sugar Land, TX, USA).…”

Atrioventricular Nodal Reentrant Tachycardia and Atrial Flutter Combined Exist Simultaneously in a 1-month-old Infant

“…Previous studies have shown that both AVNRT and AFL had an area of slow conduction located in the low posterior right atrium near the ostium of the coronary sinus 2,3 . The studies could provide theoretical support for the conversion of narrow QRS tachycardia from AVNRT to AFL.…”