Cardiac Rhythm Management
Articles Articles 2011 January


DOI: 10.19102/icrm.2011.020104

John Day, MD, FHRS, FACC

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Dear Readers,

Happy New Year and best wishes for a happy and healthy 2011!

It is with great excitement that we officially ring in 2011 with you. This year will certainly continue to yield extraordinary advancements within our field, as there are various high-profile clinical trial results expected and innovative technologies on the horizon that are moving toward approval. We have recently seen the approval of dabigatran for the prevention of atrial fibrillation-related strokes in the United States. This new medication will likely see dramatic growth within the upcoming year. Additionally, we expect to see the availability of the cryoballoon ablation technology for the treatment of atrial fibrillation in the United States in 2011.

Within this issue is a featured contribution from Andrea and colleagues at the Leipzig Heart Center in Germany entitled, A Novel Method for Catheter – Tissue – Contact Assessment During Atrial Fibrillation Ablation – The Electrical Coupling Index. Within this article, the authors discuss their clinical experience with the new contact sensor ablation catheter for atrial fibrillation ablation procedures. This new technology, currently available in Europe, will likely soon become a mainstay of ablation catheter technology.

Catheter contact sensors are of critical importance to increase the efficacy and safety of atrial fibrillation ablation procedures. When tip-to-tissue contact can be precisely controlled, the efficacy and safety of radiofrequency energy delivery can be significantly improved. In simpler terms, energy delivery with ablation procedures is equal to power multiplied by time. However, in real-world ablation procedures, the actual energy delivery may be significantly enhanced or decreased based on catheter tip-to-tissue contact.

Because catheter contact sensors have not been available in the United States as of now, we have had to rely on other surrogate measures to determine whether an effective lesion was actually created. These surrogate measures of a transmural lesion have included loss of local electrograms and electrical isolation or block. Unfortunately, due to local tissue edema at the time of the procedure, it may appear that a transmural lesion has been obtained when in reality, a transmural lesion was not achieved. Indeed, it has been reported that up to 80% of percutaneous atrial fibrillation ablation procedures will have conduction recovery of at least one pulmonary vein.

The necessity of a transmural lesion is no better illustrated than with the traditional cut-and-sew Cox Maze Procedure. In this traditional procedure, a complete transmural lesion is obtained, and 10-year atrial fibrillation success rates have approached 90%. Unfortunately, with the advent of radiofrequency and cryoenergy sources for percutaneous and surgical atrial fibrillation ablation procedures, transmurality is not always achieved, and success rates are significantly lower than those associated with the original cut-and-sew Maze Procedures.

I truly hope that catheter contact sensors can deliver on the promise of a safer and more efficacious atrial fibrillation ablation procedure. If we can truly assess catheter contact, then we may be able to minimize the risk of catastrophic complications, such as an esophageal perforation, while at the same time truly achieve a durable transmural lesion, which could increase success rates and minimize the need for redo procedures.

This issue also features a wonderful review of advanced lead extraction techniques by Dr. Ulrika Birgesdotter-Green of the University of California, San Diego Medical Center. In addition to Dr. Green's published article, I invite you to view her illustrative video presentation on lead extraction, which can be accessed at

Your feedback since the launch of Innovations in Cardiac Rhythm Management has been outstanding, and I look forward to continuing our interactions each month!


John Day, MD, FHRS,
The Journal of Innovations in Cardiac Rhythm Management
Director of Heart Rhythm Services
Intermountain Medical Center
Salt Lake City, UT