Atrial fibrillation substrate mapping with emphasis on voltage-based guidance

Figure 1 Example of a complex fractionated atrial electrogram from a paroxysmal atrial fibrillation patient. Complex fractionated atrial electrograms are fractionated electrograms comprised of multiple deflections each atrial cycle, caused by the presence of multiple asynchronous electrical activation points. The electrogram deflections often appear to be random, varying in size and shape. Peaks are usually of low amplitude, although larger peaks may be interspersed. The fractionated electrogram recordings tend to differ in patients with paroxysmal vs persistent atrial fibrillation, which may reflect the degree of substrate remodeling. Satisfactory quantitative methods to characterize these electrograms are yet lacking.