Mechanisms of Atrial Fibrillation and Their Impact on Strategies for Catheter Ablation

Abstract

Atrial fibrillation (AF) is the most common sustained arrhythmia, and is ubiquitous in clinical practice. The underlying mechanisms of initiation and maintenance of AF are complex and not completely understood. This knowledge, however, is fundamental for the development of treatment strategies for AF. Within the last 20 years, catheter ablation has played an increasing role as a rhythm control therapy. Based on diverse models for the initiation and maintenance of AF, various ablation strategies have been proposed. The cornerstone of AF ablation has been pulmonary vein isolation (PVI). In persistent AF, however, PVI alone is often not sufficient. This may be because of the structural remodelling of the atria leading to dilation and fibrosis amongst other factors. The optimal strategy for substrate modification, however, is still a matter of investigation. Current studies are concentrating on the ablation of fibrotic areas, especially in the left atrium, either detected by delayed enhancement magnetic resonance imaging or by identification of low-voltage areas as a surrogate marker. The second intensely evaluated strategy is the localisation and ablation of rotational activity. Many further randomised controlled trials will likely be needed to determine the optimal ablation strategy for individual patients.

A Review of Personalised Cardiac Computational Modelling Using Electroanatomical Mapping Data

“…However, the treatment of AF, and even atrial flutter, is uncharacteristically generalised to anatomy. 3,4 The standard anatomically-based treatment for AF, which isolates the pulmonary veins, provides only moderate performance in achieving long-term freedom from AF, particularly in patients with persistent AF. 5,6 AF is characterised by chaotic and non-synchronised waves of depolarisation propagating throughout the atrial syncytium.…”

Atrial Fibrillation Ablation – Benefits Beyond Symptom Reduction with a Focus on Patients with Heart Failure with Reduced Ejection Fraction

“…them have already been abandoned 3. While PVI is still the cornerstone of catheter ablation for paroxysmal and persistent AF and left posterior wall isolation has shown promising results, routine ablation of complexfractionated atrial electrograms and linear lesion formation are no longer used since the disappointing results of STAR AF II and other trials.…”