What EKG characteristic is commonly seen in atrial flutter?

In atrial flutter, a distinctive sawtooth pattern is observed, commonly referred to as "F-waves" or flutter waves. This characteristic pattern appears between the QRS complexes and is a result of reentrant circuits within the atria, which cause the atrial muscles to contract in a rapid and organized manner. The sawtooth pattern, typically best seen in the inferior leads (II, III, and aVF), indicates that the atria are firing at a rapid rate, often around 250 to 350 beats per minute.

While the other options may relate to different arrhythmias or cardiac conditions, they do not specifically describe the typical EKG findings associated with atrial flutter. Prominent and regular P waves could indicate a normal sinus rhythm or atrial enlargement, while a shortened QRS duration is generally not a feature of atrial flutter; instead, the QRS complexes are typically normal unless there's an underlying conduction abnormality. Inverted T waves are associated with various conditions, including myocardial ischemia, but are not specific to atrial flutter. Thus, the presence of the characteristic sawtooth pattern is what makes this finding unique to atrial flutter.