What does a flatline indicate in EKG readings?

A flatline in EKG readings, which is often referred to as asystole, indicates the absence of any electrical activity in the heart. This lack of electrical impulses means that the heart is not contracting and pumping blood, which is a critical situation typically associated with cardiac arrest or death. When an EKG shows a flatline, it signals to medical professionals that immediate intervention is necessary to try to restore normal heart rhythms and functions. Recognizing this characteristic feature of asystole allows for prompt diagnosis and treatment decisions in emergency settings.

The other choices do not accurately describe the implications of a flatline on an EKG. Normal heart function includes a regular rhythm and identifiable waves on the EKG; oxygen saturation relates to the amount of oxygen in the bloodstream and is monitored separately; and a low heart rate (bradycardia) would still show electrical activity, unlike a flatline. Understanding this distinction is crucial for effective response in clinical practice.