When the atrial flutter circuit involves the cavotricuspid isth- mus (CTI), it is labeled CTI-dependent atrial flutter. When CTI-dependent flutter involves a circuit that rotates around the tricuspid valve in a counterclockwise direction (up the septum and down the free wall), it is called typical ; less commonly, the CTI-dependent flutter circuit rotates in a clockwise direc- tion (sometimes called reverse typical ).203 Counterclockwise CTI-dependent atrial flutter is characterized electrocardio- graphically by dominant negative flutter waves in the inferior leads (so-called sawtooth waves ) and a positive P wave in lead V1 at atrial rates of 250 bpm to 350 bpm (Figure 17). Clockwise isthmus-dependent flutter shows the opposite pat- tern (ie, positive flutter waves in the inferior leads and wide, negative flutter waves in lead V1) (Figure 17). Although the atrial rates for flutter typically range from 250 bpm to 330 bpm, the rates may be slower in patients with severe atrial dis- ease or in patients taking antiarrhythmic agents or after unsuc- cessful catheter ablation.310 Atrial flutter can occur in clinical settings similar to those associated with AF, and atrial flutter can be triggered by AT or It is common for AF and atrial flutter to coexist in the same patient. 