Author + information
- Hans Kottkamp, MD∗ (, )
- Roderich Bender, MD and
- Jan Berg, MD
- ↵∗Hirslanden Hospital, Department of Electrophysiology, Witellikerstrasse 40, Zurich 8032, Switzerland
We thank Drs. Sramko and Kautzner for their interest in our manuscript (1). The success rates of current stepwise ablation approaches adding the placement of “traditional” linear lines and electrogram-based ablation after pulmonary vein (PV) isolation are disappointingly low and indicate the need for new substrate-targeted ablation strategies for atrial fibrillation (AF) therapy.
Drs. Sramko and Kautzner commented on the complex pathophysiology of AF. In fact, there is general agreement about the complexity of the roles of triggers (especially but not exclusively from the PVs), of the substrate (including atrial fibrosis), and of a variety of modulators/modifiers (including hypertension, obesity, and other cardiac risk factors, but also inflammation, cancer, and other conditions). We have analyzed data from intraoperatively obtained specimen, post-mortem autopsy findings, electroanatomic voltage mapping (EAVM) studies, and delayed enhancement (DE) magnetic resonance imaging (MRI) investigations, all of them supporting the role of atrial fibrosis for the human AF substrate, but questioning “traditional wisdom” such as AF begets AF and also the etiological role of age (2,3). Recently, atrial fibrosis was described to appear to be “a common endpoint of a wide range of AF-promoting conditions” (4).
Drs. Sramko and Kautzner commented in addition on the role of DE MRI as well as EAVM as imaging/mapping techniques or surrogates for atrial fibrosis. With respect to DE MRI, we have indicated in our manuscript that “this modality requires extensive MRI experience, and its reproducibility is still under investigation in other groups” (1). In general, new strategies and technologies that are introduced into clinical practice always have limitations. In order to appreciate the current limitations of our proposed new techniques, we included a “limitations” paragraph, which is indeed the longest in our whole manuscript (1). However, despite all limitations inherent to new techniques/technologies, we see the future role for our proposed strategies including the “box isolation of fibrotic areas,” and several clinical studies are currently being performed already.
Overall, although it seems that we look from different angles, we indeed appreciate all comments from Drs. Sramko and Kautzner because an open and respectful discussion helps to further develop the promising field of substrate modification in AF ablation for our patients.
Please note: Dr. Kottkamp is consultant with Biosense Webster; and consultant/shareholder of Kardium. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
- Kottkamp H.,
- Bender R.,
- Berg J.
- Kottkamp H.
- Nattel S.,
- Harada M.