Atrial Flutter

The bigger deflections are QRS complexes, which represent the activity of the ventricules (the bottom heart chambers). The smaller deflections represent activity of the atria (the upper heart chambers). The smaller deflections show atrial flutter deflections that are rapid (300 atrial beats per minute), regular in timing, and regular in shape, with a characteristic sawtooth pattern. The larger deflections show the ventricular response to the atrial flutter and, in this case, are regular at 75 ventricular beats per minute.