Author + information
- Received January 5, 2018
- Accepted January 11, 2018
- Published online June 18, 2018.
- Christoph Scharf, MDa,∗ (, )
- Gunter Scharf, PhDb,
- Benjamin Berte, MD, PhDa,
- Joel Bondietti, MScc,
- Lam Dang, MSc, PhDa,
- Christine H. Attenhofer Jost, MDa and
- Franz W. Amann, MDa
- aCardiovascular Center, Clinic im Park, Zurich, Switzerland
- bUniversity of Zurich, Zurich, Switzerland
- cBiosense Webster, Zug, Switzerland
- ↵∗Address for correspondence:
Dr. Christoph Scharf, Clinic im Park, Seestrasse 220, 8027 Zürich, Switzerland.
Radiofrequency ablation (RFA) of right free wall accessory pathway can be compromised by the proximity of the right coronary artery (RCA). We report a case of with a right sided accessory pathway despite previous RFA attempts with immediate loss of pre-excitation.
The accessory pathway was mapped in the right atrial free wall near a dominant RCA, but could not be ablated despite 40 W RFA. Therefore, local cooling effect was suspected and balloon occlusion of the RCA was performed during RFA. Of note, balloon occlusion of a coronary artery is a usual procedure during percutaneous transluminal coronary angioplasty. The occlusion time was 40 s during RFA of 30 s with 40 W at the same location verified by Carto mapping (Biosense Webster, Irvine, California). No complications occurred and the RCA remained normal (Figures 1 and 2⇓⇓). Permanent loss of pre-excitation was present on follow-up electrocardiogram after 10 months and no wall motion abnormalities were noted.
The cooling power of the RCA can be estimated by the following calculations: a caloric energy of 1,000 calories heats 1 l of water by 1°C. As 1 kcal/h corresponds to 1.163 W/h and the coronary flow is approximately 100 ml/min (or 6 l/h), a temperature rise of 1°C requires 6 kcal/h or 6 × 1.163 W = 7 W heating power. In other words, a local power of 7 W is needed to heat the coronary blood by 1°C with linear increase to higher target temperatures. The fact that the blood flow constantly removes the heat by bringing 38°C warm blood to the site of ablation indicates an even greater cooling capacity. As a consequence, a local temperature above 50°C seems impossible within close proximity (<5 mm) to the coronary artery.
Drs. C. Scharf and Dang are founders and stockholders of Acutus Medical. Mr. Bondietti is a Biosense Webster employee. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received January 5, 2018.
- Accepted January 11, 2018.
- 2018 American College of Cardiology Foundation