Objective: The objective of the study was to design a lead system aimed at studying atrial fibrillation (AF), while being anchored to the standard 12-lead system. Methods: The location of 4 of the 6 precordial electrodes was optimized while leaving the remaining 5 of the 9 electrodes of the standard 12-lead system in place. The analysis was based on episodes of 11 different variants of AF simulated by a biophysical model of the atria positioned inside an inhomogeneous thorax. The optimization criterion used was derived from the singular value decomposition of the data matrices. Results: While maintaining VR, VL, VF, V1 and V4, the 4 new electrode positions increased the ratio of the eighth and the first singular values of the data matrices of the new configuration about 5-fold compared with that of the conventional electrode positions. Conclusion: The adapted lead system produces a more complete view on AF compared with that of the standard 12-lead system.