Author + information
- Marek Sramko, MD, PhD∗ ( and )
- Josef Kautzner, MD, PhD
- ↵∗Department of Cardiology, Institute for Clinical and Experimental Medicine (IKEM), Videnska 1958/9, Prague 14021, Czech Republic
We read with great interest the article by Kottkamp et al. (1). We agree that atrial fibrosis may play an important role in the maintenance of atrial fibrillation (AF). However, we would like to stress a few points that seem to us important.
First, causal relationship between atrial fibrosis and AF has not been clearly confirmed. In fact, recent evidence indicates that while the atrial fibrosis naturally accompanies structural heart disease it is not directly linked to AF per se (2). There is also no direct evidence that AF can promote atrial fibrosis in humans. Clearly, the pathophysiology of AF extends far beyond the mere concept of atrial fibrosis.
Second, although magnetic resonance imaging with late gadolinium enhancement (LGE) has been extensively validated for visualization of a distinct post-infarction scar in the left ventricle, the technique has not been histologically validated for detection of predominantly diffuse pre-ablation fibrosis in the atria by any systematic study in humans or in an animal experiment. Similarly, there is no histological proof that low endocardial voltage in the atria reflects solely fibrosis. Therefore, we believe that neither low endocardial voltage nor the LGE may be interpreted as atrial fibrosis without precautious.
Our own data show no correlation between the extent of pre-ablation left atrial LGE and other characteristics of the atrial remodeling such as volume, phasic function, or bipolar voltage. Most importantly, in our experience the extent of left atrial LGE does not predict AF recurrence after ablation (3).
Thus, we feel that more solid experimental and clinical evidence is needed before clinical application of the proposed approaches to ablation of AF that are based on visualization and modification of the presumed “atrial fibrosis.”
Please note: Dr. Sramko has received speaker honoraria from Biotronik and an educational grant from Boston Scientific. Dr. Kautzner has received speaker honoraria from Biosense Webster, Biotronik, Boston Scientific, GE Healthcare, Hansen Medical, Medtronic, Siemens Healthcare, and St. Jude Medical; and has served as a consultant for Biosense Webster, Boston Scientific, Medtronic, and St. Jude Medical.
- American College of Cardiology Foundation