Association between atrioventricular node reentrant tachycardia and inducible atrial flutter

Area of Science:

• Electrophysiology
• Cardiac Arrhythmias
• Interventional Cardiology

Background:

• Atrioventricular (AV) node reentrant tachycardia and atrial flutter are reentrant arrhythmias.
• Both arrhythmias share a slow conduction area in the low posterior right atrium near the coronary sinus ostium.

Purpose of the Study:

• To evaluate atrial flutter inducibility in patients with AV node reentrant tachycardia.
• To determine if radio-frequency ablation of the slow AV node pathway affects atrial flutter inducibility.

Main Methods:

• Prospective evaluation of 91 patients using standardized atrial pacing.
• Analysis of three groups: AV node reentrant tachycardia, prior atrial flutter, and controls.
• Subgroup analysis of 34 AV node reentrant tachycardia patients before and after slow pathway ablation.

Main Results:

• Atrial flutter was significantly more inducible in AV node reentrant tachycardia (88%) and atrial flutter (92%) groups compared to controls (36%).
• Radio-frequency ablation of the slow pathway did not alter atrial flutter or atrial fibrillation inducibility.
• No significant difference in induced atrial flutter duration or cycle length before and after ablation.

Conclusions:

• A strong association exists between AV node reentrant tachycardia and inducible atrial flutter, indicating a potential common perinodal atrial substrate.
• Radio-frequency ablation targeting the AV node slow pathway does not influence the inducibility of atrial flutter.