Asystole is the absence of electrical activity. It creates a nearly flat EKG tracing and is considered cardiac arrest.

EKG monitor simulation of Asystole.
Asystole EKG / ECG monitor capture (software gen.)

Asystole is the rhythm commonly referred to in pop-culture as a "flat line." There are always some deflections from the baseline but in Asystole these are minor and consistently < 1mm in amplitude.

EKG Vocabulary:
Asystole literally means "lacking or without" systole (period of electrical activation or contraction.)
1:00 Asystole monitor capture.

Once a tracing is identified as having no deflections of a significant magnitude at all, it can be called Asystole. A Asystolic EKG is:

An EKG tracing with no deflections or identifiable features at all.

Below are several more examples of Asystole presented as monitor captures as well as on EGK graphs.

Practice Asystole EKG.
Practice Asystole EKG.
Practice Asystole ECG.
Practice Asystole ECG.
Asystole practice EKG.
Asystole practice EKG.

After becoming confident in identifying EKGs as Asystole head back to our EKG Rhythm Index to find information on another ECG. Otherwise practice interpreting novel EKGs with our EKG Generator:

Basic EKG App

Our Basic EKG Generator is free with an email signup and covers Normal Sinus Rhythm along with common arrhythmia.

Pro EKG App

Our Pro EKG Generator covers over 40 different rhythm categories, multiple display options, has Quiz and Simulation modes, and more! Try it out for just $5 for a month.