Figure 2.

The 40 Hz high‐pass filtered atrial complex in a patient with focal AF (left) and in a patient with nonfocal AF (right). In focal AF the atrial signal strength is normal also during late phase of atrial complex when the left atrium is depolarized, but in nonfocal AF late phase amplitudes are reduced. Data are expressed as superimposed display of 33 magnetometer channels. The automatically determined onset and end of atrial complex are indicated with vertical bars.