Catheter Ablation of Atrial Fibrillation: How to Modify the Substrate? | Journal Scan

Kottkamp H, Bender R, Berg J.
J Am Coll Cardiol 2015;65:196-206.
The following are 12 points to remember from this review of substrate modification in patients with atrial fibrillation (AF):

1. Atrial fibrosis consistently has been found in histological and autopsy studies of patients with AF; this is a likely cause of atrial activation abnormalities that predispose to AF.

2. A greater degree of atrial fibrosis is associated with persistent than paroxysmal AF.

3. The substrate modification that results from wide-area circumferential pulmonary vein (PV) isolation can explain why some patients do not have recurrent AF despite PV reconnection.

4. Anatomically defined ablation lines do not necessarily target regions of fibrotic substrate, and if incomplete, can cause gap-related atrial flutter.

5. Complex fractionated atrial electrograms (CFAEs) can be markers of slowed conduction or pivot points of wavelets.

6. Ablation of CFAEs has been shown to provide incremental benefit beyond PV isolation in patients with high-burden paroxysmal and persistent AF.

7. A major limitation of CFAEs is their nonspecificity and instability.

8. A possible strategy for more specific targeting of the atrial AF substrate is to isolate areas of low voltage (such as the posterior wall) after PV isolation.

9. Delayed-enhancement magnetic resonance imaging can identify areas of atrial fibrosis that might guide a tailored approach to atrial substrate modification.

10. Encouraging clinical results have been achieved with focal impulse and rotor modification guided by computational mapping of atrial electrograms recorded with a 64-pole basket catheter.

11. Early results suggest that body surface mapping of AF might be helpful for targeting high-density regions of stable and unstable rotors.

12. Ongoing fibrosis despite sinus rhythm after AF ablation can explain late recurrences of AF despite durable PV isolation.

Clinical Topics: Arrhythmias and Clinical EP, Noninvasive Imaging, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Magnetic Resonance Imaging

Keywords: Atrial Fibrillation, Atrial Flutter, Autopsy, Body Surface Potential Mapping, Cost of Illness, Electrophysiologic Techniques, Cardiac, Heart Atria, Magnetic Resonance Imaging, Pulmonary Veins, Recurrence

< Back to Listings