What cardiovascular condition would most likely not show ST-segment elevation on EKG?

Atrial flutter is a type of supraventricular tachycardia characterized by a rapid reentrant circuit in the atria. On an Electrocardiogram (EKG), atrial flutter typically presents with a "sawtooth" pattern of flutter waves, most often seen in leads II, III, and aVF, rather than exhibiting ST-segment elevation.

In contrast, myocardial infarction is commonly associated with ST-segment elevation, which reflects acute injury to the myocardial tissue due to ischemia. Ventricular tachycardia can also show ST-segment changes depending on the type and condition, and right bundle branch block may alter the morphology of the QRS complex but does not generally cause ST-segment elevation. Therefore, due to its distinct EKG characteristics and the absence of ST-segment elevation, atrial flutter is the correct answer.