Which rhythm is characterized by a "sawtooth" appearance on the EKG?

The rhythm characterized by a "sawtooth" appearance on the EKG is atrial flutter. This distinctive pattern is referred to as "F-waves" or "sawtooth waves" because of their resemblance to a sawtooth edge in their morphology. The sawtooth appearance occurs due to the rapid reentrant circuit typically found in the right atrium, leading to continuous atrial depolarization at a rate generally between 240 to 340 beats per minute.

This visual characteristic is crucial for identifying atrial flutter when examining an EKG strip since it helps distinguish this rhythm from others that may present with irregular or chaotic waveforms, such as atrial fibrillation, which lacks organized atrial electrical activity, or other rhythms that do not display such a regular pattern of consistent morphology.

Recognizing the sawtooth pattern is essential for diagnosing atrial flutter and understanding its clinical significance, such as the risk of thromboembolism and the approaches to management.