There is a host of experimental data suggesting that spiral electrical waves, also known as rotors or focal sources, are important sustaining mechanisms of atrial fibrillation (AF) and other cardiac arrhythmias.1-14 Although such rotors in AF have been demonstrated experimentally in animal models, up until now those same critical circuits have not been clearly visualized in humans or addressed using catheter ablation.
The Birth of a Revolutionary Technology
After more than a decade of intense scientific research focused on identifying the fundamental localized mechanisms that sustain AF in an individual patient, the technology used to visualize and localize these rotors was conceived. This technology is the Topera® Rotor Mapping solution.
The definition of a “Rotor”?
As a result of these early studies, an appropriate definition of “rotor” emerged. A rotor is characterized as consistent rotational activity around a center, which is maintained for hundreds to thousands of cycles spanning several minutes. This definition excludes transient rotational activity that results from passive activation.
Initially, it was very important to demonstrate that rotors do in fact exist in patients as an important sustaining mechanism of AF. This validated that the Topera Rotor Mapping Solution could accurately identify and visualize rotors in patients with AF. Early research was performed using what is now the RhythmView® Workstation with a broad range of AF phenotypes and AF patients who were undergoing a first ablation as well as those who had failed conventional ablation.8-11
This early research showed that the Topera Rotor Mapping Solution identifies rotors in virtually all patients. Moreover, it was also discovered that human AF can be sustained by a small number of these rotors, which are stable over prolonged periods of time. The following are highlights of these published Abbott Electrophysiology studies, with a particular emphasis on results related to rotor stability:
- Continuous analysis with the Topera Rotor Mapping Solution showed that the location of rotors is stable, in that they migrate or wobble over a small area with precession 1 cm.8
- The stability of these rotors is maintained over time, where the location remained consistent for 115 ± 57 minutes.7
Recent Clinical Confirmation
More recent clinical studies from multiple laboratories have demonstrated that AF can be sustained by a small number of stable rotors/focal sources, which can be reliably identified with the Topera Rotor Mapping Solution.6,7,9,11 The following are highlights of these more recent studies:
- Abbott Electrophysiology identified stable rotors in 98% of AF patients studied.6,9
- These rotors were stable for thousands of cycles-even up to several months.7
- Patients with paroxysmal atrial fibrillation have fewer rotors as compared to those with persistent atrial fibrillation.11
- Rotors exist in both atria, with as many as 1/3rd in the right atrium.9
The Clinical Significance
The ability to diagnose such local mechanisms has enabled treatment approaches to become more patient-specific by focusing on just a few critical areas in each individual patient’s heart. This is important, as most treatment approaches to date are one-size-fits-all with sub-optimal results. A more reasonable philosophy is to tailor therapy for each individual’s specific physiology, which can only be done with precise location information. Abbott’s Topera Rotor Mapping Solution is a tool used to do just that.
- Arshad A, Mittal S, Musat D, et al. Long-Term Success From FIRM Ablation is Maintained Even if Acute Endpoint is Not Achieved. Heart Rhythm 2013; 10(P004-133).
- Berenfeld O, Mandapati R, Dixit S, et al. Spatially distributed dominant excitation frequencies reveal hidden organization in atrial fibrillation in the Langendorff-perfused sheep heart. J Cardiovasc Electrophysiol. Aug 2000;11(8):869 – 879.
- Gray R.A., Jalife J., Panfilov A.V., et al. Mechanisms of cardiac fibrillation. Science 1995;270:1222-1223.
- Jalife J., Berenfeld O., Skanes A.C., Mandapati R. Mechanisms of atrial fibrillation: mother rotors or multiple daughter wavelets, or both? J Cardiovasc Electrophysiol 1998;9:S2-S12.
- Mandapati R., Skanes A.C., Berenfeld O., Chen J., Jalife J. Stable microreentrant sources as a mechanism of atrial fibrillation in the isolated sheep heart. Circulation 2000;101:194-199.
- Miller JM, Krummen DE, Narayan SM et al. Multicenter Validation of Focal Impulse and Rotor Modulation (FIRM) Ablation for Atrial Fibrillation (CONFIRM- Multicenter Validation). AHA Scientific Sessions, Nov 2013; Oral presentation.
- Narayan SM, Krummen DE, Enyeart MW, Rappel W. Computational mapping approach identifies stable and long-lived electrical rotors and focal sources in human atrial fibrillation. PLos One 2012; 7:e46034.
- Narayan SM, Krummen DE and Rappel WJ. Clinical Mapping Approach to Diagnose Electrical Rotors and Focal Impulse Sources for Human Atrial Fibrillation. J Cardiovasc Electrophysiol. 2012; 23:447-454.
- Narayan SM, Krummen DE, Shivkumar K, Clopton P, Rappel W-J, Miller J. Treatment of atrial fibrillation by the ablation of localized sources: the conventional ablation for atrial fibrillation with or without focal impulse and rotor modulation: Confirm trial. J Am Coll Cardiol 2012; 60:628– 636.
- Narayan SM, Patel J, Mulpuru S, Krummen DE. Focal impulse and rotor modulation (FIRM) ablation of sustaining rotors abruptly terminates persistent atrial fibrillation to sinus rhythm with elimination on follow-up. Heart Rhythm 2012;9:1436 –1439.
- Narayan SM, Krummen DE, Clopton P, Shivkumar K, and Miller JM. Direct of Coincidental Elimination of Stable Rotors or Focal Sources May Explain Successful AF Ablation: On-Treatment Analysis of the CONFIRM Trial. J Am Coll Cardiol 2013;60(2):138-147.
- Pertsov A.M., Davidenko J.M., Salomonsz R., Baxter W.T., Jalife J. Spiral waves of excitation underlie reentrant activity in isolated cardiac muscle. Circ Res. 1993;72:631-650.
- Shivkumar K, Ellenbogen, Kenneth A, et al. Acute termination of human atrial fibrillation by identification and catheter ablation of localized rotors and sources: first multicenter experience of focal impulse and rotor modula- tion (firm) ablation. J Cardiovasc Electrophysiol 2012.
- Zlochiver S, Yamazaki M, Kalifa J, Berenfeld O. Rotor meandering contributes to irregularity in electrograms during atrial fibrillation. Heart Rhythm 2008;5: 846 – 854.