Multiple saw-tooth p-waves are noted at a rate of 300. Variable conduction may occur, or more commonly, conduction occurs at a 2:1 3:1 or 4:1 interval with ventricular rates of 150bpm, 100bpm and 75bpm respectively.

The common form of atrial flutter involves a single reentrant circuit with circus activation in the right atrium around the tricuspid valve annulus .