Asystole

Welcome to our asystole reference page that provides a definition and synopsis of EKG features. Links to our practice drills, quizzes, lessons and interactive guides can be found below.

Asystole Definition

Asystole is a cardiac arrest rhythm with no discernible electrical activity on the EKG monitor. It is a flatline EKG, P Waves and QRS complexes are not present The heart is not functioning. It is a life-threatening condition that requires immediate action.

NIH Expanded Definition

The heart has an internal electrical system that controls the rhythm of the heartbeat. Problems can cause abnormal heart rhythms, called arrhythmias. There are many types of arrhythmia. During an arrhythmia, the heart can beat too fast, too slow, or it can stop beating. Sudden cardiac arrest (SCA) occurs when the heart develops an arrhythmia that causes it to stop beating. This is different than a heart attack, where the heart usually continues to beat but blood flow to the heart is blocked.

There are many possible causes of SCA. They include coronary heart disease, physical stress, and some inherited disorders. Sometimes there is no known cause for the SCA.

Without medical attention, the person will die within a few minutes. People are less likely to die if they have early defibrillation. Defibrillation sends an electric shock to restore the heart rhythm to normal. You should give cardiopulmonary resuscitation (CPR) to a person having SCA until defibrillation can be done.

If you have had an SCA, an implantable cardiac defibrillator (ICD) reduces the chance of dying from a second SCA.

Asystole is also a condition used in certifying clinical death.

Asystole Treatment

The first step is to quickly check that the apparent asystole is not an equipment failure or a rhythm that is similar to a flat line.

Check for loose or discounnect leads. Verify that the ECG monitor has power. Check the signal gain on the ECG monitor.

Certain venticular fibrillation tracings may appear at first to be aystole.

Treatment should follow your facility's protocols. Refer to the ACLS algorithms for more information.

ICD Codes

Relevant ICD-10 code are I46, I46.9

Asystole ECG

The following table summarizes the key features of the Asystole ECG rhythm strip.

RhythmNot present
RateAbsent
P WaveAbsent
PR IntervalAbsent
QRSAbsent
NotesConfirm with multiple leads
Asystole ecg strip


EKG Training

A good starting point for learning EKG interpretation, including asystole, is our EKG Basics training course. The course provides training on the key features of an EKG tracing. These features include observing P-wave forms, measurement of EKG intervals and segments, assessment of rhythm, calculating heart rate, and the evaluation of other relevant wave segments. The arrhythmia practice drills allow students to build skills interactively.

EKG Basics

EKG Practice Drills

The heart arrhythmia practice drills provide a test EKG tracing and users are asked to identify the type of arrhythmia. Many of these drills include tachycardia EKG tracings. Each answer is immediately evaluated and the correct classification of the EKG tracing is provided, along with a detailed explanation. A directory of arrhythmias is also provided.

Arrhythmia Practice Drills

ECG Quiz

The quiz is structured like a classroom exam. The quiz present twenty EKGs. Users answer each question and at the end of the quiz, a fully graded report is provided. This graded report provides scoring as well as the correct answer to each question. Top scores and mean scores are also provided. This quiz draws its questions from a library of over 300 EKGs, allowing users to take the quiz multiple times.

ECG Quiz

ECG Monitor Challenge (beta version)

Try the beta version of our ECG monitor challenge. This quiz uses a simulated patient monitor with moving waveform instead of a paper tracing. As with the quiz described above, twenty questions are presented, then a graded report is available.

ECG Monitor Challenge