Current Status and Future of Cardiac Mapping in Atrial Fibrillation

AF is a major concern in general population worldwide. Every year, 3 million suffer from AF related stroke, 1.5 million die from AF related stroke within a year, and 1 million are severely disabled by AF related stroke. Only 1% of AF patients underwent a treatment such as ablation or AF surgery. 99% remain as they are or prophylactic anticoagulation medication only. The reason why is due to the limitation in diagnostic mapping and ablation treatment. Incomplete, vague and fragmented maps give us incomplete AF information, and lead to incomplete cure chance. Standard 12-lead ECG, which composed of 6 bipolar Einthoven limb leads and 6 unipolar Wilson pre-cordial leads, are used for more than 100 years giving us the information about rhythm, electric axis, activation sequence, and repolarization pattern. However, the F wave information of standard ECG signals during AF has limitation that only a few signals are available to show whether AF or not, or little information of source or location of its origin. The exact location of source origin and propagation route or pattern of reentry is too difficult to be elucidated by conventional lowsensitive ECG method due to its very weak signal amplitude of F-wave. Therefore, in order to manage AF successfully, we should get detailed information of AF activity in atrium using a high sensitive mapping methodology. Accurate mapping is the essential to successful treatment of arrhythmia. Endocardial mapping techniques for AF are now well developed and its accuracy reached high to treat AF effectively, however, they demand invasiveness, moderate costs and selection of patients. They are not suitable for mass screening to general population yet. Non-invasive mapping for AF is still far from bed-side due to its insufficient information of AF, not enough to detect F wave and to make a sufficient map to treat AF. According to the recently updated worldwide survey on AF ablation by Cappato et al. [1] in 2010, anti-arrhythmic drug-off success rate and overall success rate are 75% and 83% for paroxysmal AF, 65% and 75% for persistent AF, and 63% and 72% for long-standing persistent AF. Major complications were reported 4.5% from catheter ablation for AF. They reported that CARTO-guided left atrial circumferential ablation (48% of all treated patients) and Lasso-guided ostial electric disconnection (27% of all treated patients) were the most commonly used techniques for AF treatment. To improve the success rate, exact cardiac mapping of AF is essential. In this chapter, we described several topics of cardiac map, such as history, importance, composition, classification, basic principle, clinically available maps, and my study work, Magnetocardiography Action Potential Activity mapping for AF and future frontiers.