Matrix metalloproteinases and atrial structural remodeling.

Atrial fibrillation (AF) is a common arrhythmia, affecting approximately 5% of the population older than 65 years; the arrhythmia is associated with significant morbidity and mortality, and it is challenging and often frustrating to treat (1,2). There is a tendency for AF to become chronic and more resistant to cardioversion with increasing duration of the arrhythmia (3). Although the details are poorly understood, persistence of AF is thought to result from the atrial remodeling that occurs.