Afib Treatment Challenges & Solutions
Effectively managing patients with atrial fibrillation (AF or Afib) is one of the biggest challenges facing cardiac medicine. For many years, treatment for Afib was limited to anticoagulant and anti-arrhythmic agents. Despite the recent development of new pharmacologic treatments, these options have not reduced complications.1,2
Ablation & Atrial Fibrillation
Over the past 15 years, cardiac ablation has been established as a treatment option and is often used by cardiac electrophysiologists. The current treatment strategy is to isolate the pulmonary veins (PVs) of the left atrium. Ablation for atrial fibrillation targets isolation of the foci firing from the PVs and triggers the abnormal activity during an Afib episode. In this respect, technologies have advanced in creating a better anatomical ablation and reported success rates are generally better than drug therapy.3-5
Today’s ablation for atrial fibrillation also requires a good representation of the left atrial anatomy and the PVs. This is achieved by utilizing mapping systems that are capable of integrating pre-acquired images from either a CT or MRI. Ablation technologies have also improved by using either radiofrequency-irrigated catheters or cryogenic balloons.
However, isolation of PVs alone is often suboptimal as many Afib patients require multiple ablations.6-8 Most physicians agree that an additional ablation strategy is required. The most common of these strategies include:
- Roof line ablation
- Left sided (mitral) isthmus
- Isolation of the superior vena cava
- Isolation of left atrial appendage
- Cavo-tricuspid line
- Complex fractionated electrograms or CFAE
Electrophysiologists generally choose a strategy based on an individual patient’s needs and the type of atrial fibrillation. Despite the increase in the number of ablation options and their frequency, success rates have not significantly improved.6-8 Two questions remain: Is anatomical ablation enough for treatment of Afib and how important is a better understanding of mechanisms that cause Afib?
Identifying Afib at the Source
A new mechanistic approach to treating Afib has emerged. In contrast to the common anatomical strategy of PVI, it offers diagnostic capabilities that are individualized to each patient. Patients are selected for ablation only if the diagnostic or mechanistic part indicates and presents personalized targets.
The Topera® Physiologic Rotor Mapping Solution
This new approach is achieved using the Topera Physiologic Rotor Mapping Solution, which includes FIRMap®, a diagnostic basket catheter that is connected to the RhythmView® Workstation. FIRMap has 64 evenly spaced electrodes, distributed between 8 splines and is inserted into the right and then left atrium sequentially, in order to identify rotational waves (rotors) creating surrounding disorganized electrical activity or fibrillation. Once FIRMap collects the electrical activity, it transfers the information to the RhythmView Workstation for signal processing and provides a visual representation of the electrical maps, allowing the identification of rotors. Physicians then use this information in combination with other systems in the EP lab to determine the appropriate treatment. If cardiac ablation is indicated, they may use any ablation device to address the selected locations. Additional diagnostic electrical maps are acquired and the process repeated until the elimination of all rotors is confirmed. This new technology is capable of identifying rotors but most importantly, confirms elimination of rotors.9-11
- Van Gelder IC, Groenveld HF, Crijns HJ et al. Lenient versus strict rate control in patients with atrial fibrillation. N Engl J Med 2010;362:1363-73.
- Roy D, Talajic M, Nattel S et al. Rhythm control versus rate control for atrial fibrillation and heart failure. N Engl J Med 2008;358:2667-77.
- Oral H, Pappone C, Chugh A et al. Circumferential Pulmonary-Vein Ablation for Chronic Atrial Fibrillation. N Engl J Med 2006;354:934-941.
- Wilber DJ, Pappone C, Neuzil P et al. Comparison of antiarrhythmic drug therapy and radiofrequency catheter ablation in patients with paroxysmal atrial fibrillation: a randomized controlled trial. JAMA 2010;303:333-40.
- Morillo C, Verma A, Kuck KH et al. Radiofrequency Ablation Vs Antiarrhythmic Drugs As First-line Treatment Of Symptomatic Atrial Fibrillation: (RAAFT 2): A Randomized Trial (Late Breaking Abstract). Heart Rhythm 2012;9.
- Nademanee K, McKenzie J, Kosar E et al. A new approach for catheter ablation of atrial fibrillation: mapping of the electrophysiologic substrate. J Am Coll Cardiol 2004a;43:2044-2053.
- Tanner H, Hindricks G, Kobza R et al. Trigger activity more than three years after left atrial linear ablation without pulmonary vein isolation in patients with atrial fibrillation. J Am Coll Cardiol 2005;46:338-43.
- Yao Y, Zheng L, Zhang S et al. Stepwise linear approach to catheter ablation of atrial fibrillation. Heart Rhythm 2007;4:1497-504.
- Narayan SM, Krummen DE, Shivkumar K, et al. Treatment of Atrial Fibrillation by the Ablation of Localized Sources: CONFIRM (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation) Trial. J Cardiovasc Electrophysiol. 2012; 60(7):628-636.
- Narayan SM, Baykaner T, Clopton P, Schricker A, Lalani G, Krummen DE, Shivkumar K, Miller JM, Ablation of Rotor and Focal Sources Reduces Late Recurrence of Atrial Fibrillation Compared to Trigger Ablation Alone, Journal of the American College of Cardiology (2014), doi: 10.1016/j.jacc.2014.02.543.
- Miller JM, Kowal RC, Swarup V, et al. Initial Independent Outcomes from Focal Impulse and Rotor Modulation Ablation for Atrial Fibrillation: Multicenter FIRM Registry. J Cardiovasc Electrophysiol. 2014; 25(9):921-929.