The Heart Rhythm Society’s 32nd Annual Scientific Sessions (May 4-7) in San Francisco is a must-attend event for anyone involved with cardiac arrhythmias. The conference will bring together leading experts from around the globe to highlight the latest research, technologies, therapies and approaches to patient care in our field, and will include more than 250 sessions, 900 faculty and 130 exhibitors.

Given Heart Rhythm 2011’s proximity to Silicon Valley, it’s fitting that the focus of this year’s sessions will be technology. As Anne M. Gillis, MD, FHRS, the Chair of Scientific Sessions Program Committee, notes in her welcome letter, “advancements in the area of technology are essential to the overall evolution of investigation and treatment for patients.”

An exciting technology development for atrial fibrillation is delayed enhancement magnetic resonance imaging (DE-MRI), which Cardiovascular Business called a potential “game changer” in its January 2011 cover story on AF ablation. Particularly promising is its use as a pre-ablation tool for investigating tissue injury near the posterior left atrium (LA) wall. When used with custom software tools and computer algorithms, DE-MRI not only calculates the extent of LA injury, but also predicts the success of first-time ablations as well as optimal rate/rhythm control strategies.

I’ll be writing more about DE-MRI applications in the May issue of EP Lab Digest. In the meantime, here’s a preview of some highlights and results from the 12 posters the CARMA Center will be presenting at Heart Rhythm 2011:

• Patients were classified into two groups with minimal scar (total LA scar <10%) and extensive scar (>20%), and classified based on the extent of LA fibrosis, which was detected using DE-MRI and the Utah Classification System. The study found that pre-existent LA tissue with fibrotic remodeling and dilation influenced the degree of radiofrequency-induced scar tissue that is formed following AF ablation.
• DE-MRI was used to assess which clinical parameters were most influential in the LA remodeling process. Based on results from multivariate analysis, AF burden was shown to be the most important predictor for advanced staging classification (Stage III and IV). The study concluded that the duration of time spent in AF is the most powerful predictor of AF structural remodeling and that LA enhancement is associated with increased LA enhancement seen on DE-MRI.
• Factors associated with the failure of multiple ablation procedures were evaluated using DE-MRI. The results showed that patients who failed repeat AF ablation had structural LA remodeling. Although repeat procedures resulted in more LA scar, the increase in total LA scar and number of PVs with complete scarring did not influence repeat ablation success.

Nassir F. Marrouche, MD is the Executive Director of the Comprehensive Arrhythmia Research & Management Center, Director of Electrophysiology Laboratories, and Director of the Atrial Fibrillation Program at the University of Utah School of Medicine, Division of Cardiology.