/* ]]> */



Asystole or “flatline”

EKG Asystole Rhythm Strip

Asystole is not actually a true rhythm but rather is a state of no cardiac electrical activity. The main treatment of choice for asystole is the use of epinephrine and CPR.

Asystole is treated using the right branch of the pulseless arrest algorithm. Click below to view the pulseless arrest algorithm diagram. When done click again to close the diagram.
Pulseless Arrest Algorithm Diagram.

During asystole, there is no blood flow to the brain and other vital organs. This results in very poor outcomes if resuscitation is successful.

If asystole is visualized on the monitor, you should ensure that all leads are connected properly. If all leads are properly connected, you should rapidly assess for any underlying causes for the asystole.

As with pulseless electrical activity (PEA), asystole can have possible underlying causes which can be remembered using the H’s and T’s mnemonic.

In the following video, asystole is depicted on the defibrillator monitor and suggestions for treatment are given. Please allow several seconds for the video to load.


Question: What can sometimes be mistaken for asystole during a code?
click here for answer

fine ventricular fibrillation. Another way you can help determine the difference between asystole and fine VF is to increase the signal gain on the monitor. Increasing the signal gain will help you visualize any electrical impulses that indicate fine VF.

  82 Responses to “Asystole”

  1. Thank you Jeff.

  2. I think you should mention if any asystole you’re unsure of, you can zoom the rhythm or increase sensitivity on the monitor to look for minimal electrical activity with rhythm.

  3. Are both Asystole and fine VF pulseless, If yes, what do you do to assure you ars doing the right thing during CPR?

    • Yes they are both pulseless. You can’t always be sure that you are doing the right thing because you cannot always be sure you are dealing with VF or asystole. One way is to evaluate the situation. If you are dealing with a patient who was found unresponsive, is cool to touch, cyanotic, and the time of cardiac arrest is not known you are probably dealing with asystole. If the arrest was witnessed and it has been a very short time since the collapse there is a good chance you are dealing with fine VF. A health care provider might try increasing the signal gain on the defibrillator if it does not waste much time, but if in doubt. Shock the patient once. If it is asystole, you will get no response. If it is fine VF, it could save their life.

      Kind regards,

  4. How long should a asystole code last? How long is to long?

    • It really depends on a lot of factors. If there is a reversible factor that can be identified (H and T’s) then asystole can be reversed and every effort should be made to reverse any reversible factors.
      Also, you have to take into consideration the length of time that the patient has been in asystole. There are too many factors to say that a code with asystole should last “ “ about of time. Or “ “ is to long for a code when asystole is present.
      One thing that I have been told it that the patient in asystole should be warm and dead. This means that you have effectively circulated the patients’ blood through your CPR efforts and there has been no response from the patient.
      Carefully consider any H and T’s that could be causing an asystole before you give up and call a code. Use good team communication to work together to determine when it is best to stop a code.

      Kind regards,

  5. I’m going to take my acls next week..im quite nervous since it is my first time to take this..im searching in the internet for a understandable tool for my study guide, and luckily i found this site .. im praying and hoping for a positive result..wish me luck..thanks..

    • Good luck to you with certification. You will do great!
      Make sure to use the checklist in the download library to ensure that you cover all of the material on the website. You can leave a comment on the home page to let me know how your certification goes.

      Kind regards,

  6. If rhythm on monitor is asystole do I have still to check pulse ? Or start CPR immediately.
    Checking rhythm on monitor alone is enough or we need to check pulse for PEA ?

    • A pulse check is always a good idea, but it should not take longer than 10 seconds. If you cannot feel a pulse within 10 seconds, start CPR.
      If you saw a rhythm change from pulseless VT or VF to asystole then you would not need to check for a pulse. You would continue CPR with rhythm checks between each 5 cycles of CPR.

      Kind regards,

 Leave a Reply