Myocardial fibrosis and atrial fibrillation

Abstract

Atrial fibrillation is the most prevalent arrhythmia, and tends to progress. Any structural changes in the heart may lead to its progressive remodelling with increased deposition of connective tissue and fibrosis. Predominance of collagen types I and III synthesis over its degradation leads to accumulation of fibers and to fibrosis. Increase of atrial fibrosis is usually found on autopsy and biopsy. There is relation revealed, of atrial fibrosis grade and postsurgery atrial fibrillation. The mechanisms participating in the structural remodelling and progression of atrial fibrosis are not studied well enough, but there is known role of renin-angiotensinaldosterone system, transforming growth factor, inflammation and matrix metalloproteases. As an alternative, one should consider non-invasive diagnostic methods: magnetic resonance imaging of the heart and biomarkers level measurement. Hyperactivation of the renin-angiotensin-aldosterone system facilitates structural remodelling of the heart and progression of atrial fibrosis. Hyperexpression of the transforming growth factor leads to selective atrial fibrosis, heterogeneity of excitation conduction and fibrillation onset. Matrix metalloproteases are the marker of extracellular degradation. Study of fibrosis biomarkers makes it to increase significantly the efficacy of atrial fibrillation course prediction.

Keywords

• atrial fibrillation
• renin-angiotensin-aldosterone system
• myocardial fibrosis
• inflammation