This rhythm strip shows atrial flutter. The characteristic features demonstrated here include a rapid regular atrial rate, typically in the range of approximately 300 per minute, and an atrial wave form that has a saw-tooth configuration. When untreated, as in this case, the ventricle typically responds to every other atrial beat producing, in this example, a heart rate of 140 beats per minute. With treatment, A-V block increases, reducing the ventricular response.