This is a three channel recording where the pacemaker is first in an A00 mode at 70/min. Note the atrial flutter waves marked by the yellow arrows. The atrial pacing rate is then increased to about 375/min. (red arrows) with termination of the atrial flutter. The effect of the atrial pacing is clearly seen as the flutter waves are faster (turquoise arrows compared to yellow arrows). Note that the EKG recorder is placing stimulus markers (blue arrow) that are correct for the lower rates but does not mark most of the stimuli at the rapid pacing rate. On the right there is a nodal escape rhythm competing with the A00 pacing at 70/min. Many dual chamber pacemakers offer this atrial rapid pacing option. Although the risk of embolism is low in atrial flutter anticoagulation should be considered before a conversion is attempted.