Figure 5.

(A) Activation latency curves in a representative control patient at baseline (blue) and during isoproterenol (red) show a similar reduction in minimum conducted S2 and maximum activation latency to AF patients. However, action potential duration restitution slope (B) remains <1 during isoproterenol, as shown in this representative patient. (C) shows failure of shortest conducted extrastimulus to induce AF in a control patient during isoproterenol.