When responding to sudden cardiac arrest, rescuers may need to perform CPR and use an automated external defibrillator (AED) to help restore an effective heart rhythm. The AED guides users through the process, including when to pause CPR so the device can analyze the heart rhythm and determine whether a shock is needed.
This guide explains what to do while an AED analyzes the heart’s rhythm, when to pause and resume CPR, and common mistakes to avoid during AED analysis.
What Happens When an AED Analyzes the Heart Rhythm?
When an automated external defibrillator (AED) analyzes the heart rhythm, it uses electrode pads placed on the person’s chest to check the heart’s electrical activity. The device uses this information to identify whether the heart has a shockable rhythm, such as ventricular fibrillation or pulseless ventricular tachycardia.
After analyzing the heart rhythm, the AED indicates whether a shock is advised and announces the result through voice prompts or displays it on the screen.
What is Very Crucial to Do While the AED is Analyzing the Heart Rhythm?
During AED rhythm analysis, rescuers must pause and follow the device’s prompts before continuing resuscitation. Following the correct steps allows the AED to analyze the heart rhythm accurately and helps rescuers respond appropriately.
Stop Chest Compressions and Rescue Breaths When Prompted
When the AED instructs rescuers to stand clear, stop CPR, including chest compressions and rescue breaths. This pause allows the AED to analyze the heart rhythm without movement interfering with its assessment.
Tell Everyone to Stand Clear During AED Analysis
Say, “Everyone, stand clear!” so all rescuers and bystanders know not to touch the person while the AED analyzes the heart rhythm. Check that everyone has moved away before the analysis continues.
Make Sure Nobody Is Touching the Person
Make sure everyone stays clear of the person and the electrode pads while the AED analyzes the heart rhythm. This prevents movement or contact from interfering with the analysis.
Allow the AED to Complete Its Heart Rhythm Analysis
Wait for the AED to finish analyzing the heart rhythm. Do not move the person or interrupt the process unnecessarily. The device will determine whether the detected rhythm is shockable and provide voice prompts or visual instructions for the next step.
Follow the AED’s Instructions
Once the analysis is complete, listen carefully to the AED’s instructions. If a shock is advised, make sure everyone is clear before delivering it. If no shock is advised, resume CPR immediately when instructed and continue following the AED’s prompts.
Why Is It Important to Stay Clear During AED Analysis?
Staying clear during AED analysis helps the device assess the heart rhythm accurately, protects rescuers and bystanders, and supports safe AED use.
Ensures Accurate Heart Rhythm Analysis
Movement during AED analysis can interfere with the device’s ability to assess the heart rhythm accurately. Ensure everyone stays clear of the person until the analysis is complete.
Protects Rescuers and Bystanders During Shock Delivery
If the AED advises a shock, ensure nobody is in contact with the person before delivering it. This helps prevent rescuers and bystanders from accidentally receiving the electrical shock.
Supports Safe and Responsible AED Use
Following AED instructions and established safety procedures helps rescuers respond responsibly during a cardiac emergency. Good Samaritan laws may protect rescuers who provide emergency assistance, but the protections vary by state and situation.
Should You Continue CPR While the AED Is Analyzing?
No. You should stop CPR when the AED prompts you to stand clear for heart rhythm analysis and resume when the AED gives further instructions.
Do not continue compressions, provide rescue breaths, or interrupt the analysis to check the person’s pulse.
However, CPR should generally continue while another rescuer prepares the AED. The timing of the pause is important.
While the AED Is Being Prepared
If more than one rescuer is available, one person should continue CPR while another turns on the AED, exposes the person’s chest, and attaches the electrode pads. This reduces interruptions to chest compressions.
If you are alone, follow the AED’s instructions and minimize interruptions as much as possible.
When the AED Starts Analyzing
Once the device prompts for rhythm analysis, everyone must stand clear. Stop compressions and ventilations, ensure nobody is touching the person, and wait for the AED to complete its assessment.
After the Analysis
Follow the next prompt immediately. If the AED advises a shock, ensure everyone is clear before delivering it. If no shock is advised, resume CPR immediately, following the AED’s prompts.
Keeping interruptions short helps maintain blood flow to the brain and other vital organs during cardiac arrest.
What Happens After the AED Analyzes the Heart Rhythm?
After analyzing the heart rhythm, the AED will indicate whether a shock is advised and provide instructions for the next step. The appropriate response depends on the device’s recommendation.
If the AED Advises a Shock
A shock is advised when the AED detects a heart rhythm that can be treated with defibrillation.
- Ensure everyone is clear of the person.
- Deliver the shock as instructed by the AED. With a semi-automatic AED, press the shock button when prompted. A fully automatic AED delivers the shock automatically after warning everyone to stand clear.
- Resume CPR immediately after the shock, beginning with chest compressions.
Continue following the AED’s prompts and perform CPR until the device instructs you to pause for another rhythm analysis or emergency medical personnel take over.
If the AED Says No Shock Is Advised
A “no shock advised” message means the AED has not detected a heart rhythm for which it recommends a shock at that time. It does not necessarily mean the person has recovered.
Resume CPR immediately, starting with chest compressions. Continue CPR as directed by the AED, even if no shock is recommended, until the device prompts another analysis or emergency medical personnel take over.
If the AED Prompts for Another Analysis
Continue CPR until the AED instructs you to stop for another rhythm analysis. When prompted, ensure everyone is clear of the person and allow the device to assess the heart rhythm.
Follow the AED’s next instructions and resume CPR when directed. Keep the AED attached and switched on until emergency medical personnel take over or instruct you otherwise.
Common Mistakes to Avoid During AED Analysis
Avoid these mistakes to help the AED analyze the heart rhythm accurately and ensure CPR resumes promptly.
Continuing Chest Compressions During Analysis
Stop chest compressions when the AED prompts you to stand clear. Continuing compressions during analysis can interfere with the device’s assessment.
Allowing Contact With the Person
Ensure all rescuers and bystanders stay clear while the AED analyzes the heart rhythm. Contact during analysis can interfere with the device’s reading.
Checking for a Pulse During Analysis
Do not interrupt the AED’s analysis to check for a pulse. Follow the device’s prompts and allow it to complete the assessment.
Delaying CPR After Analysis
Resume CPR immediately after a shock or when the AED advises that no shock is needed. Begin with chest compressions and follow the device’s instructions.
Assuming No Shock Means the Person Has Recovered
A “no shock advised” message does not mean the person has recovered. Continue CPR unless the person shows clear signs of recovery or emergency medical personnel direct you otherwise.
Ignoring the AED’s Voice Prompts
Follow the AED’s voice prompts or visual instructions throughout the process. These instructions guide rescuers on when to stand clear, deliver a shock, resume CPR, and pause for another analysis.
Without hands-on practice, you may make common mistakes when using an AED or performing CPR. Enroll in our AHA BLS course to develop practical skills and learn how to respond correctly during a cardiac emergency.
Be Prepared to Use an AED Correctly
An automated external defibrillator (AED) is an essential tool in responding to sudden cardiac arrest. It analyzes the heart rhythm, determines whether a shock is advised, and guides rescuers through the next steps. Learning to use an AED and perform CPR prepares you to respond effectively to a cardiac emergency.
New York CPR Classes offers AHA BLS, ACLS, and PALS courses for healthcare professionals who need to develop or maintain their resuscitation skills. With multiple training locations across New York, you can find a convenient place to complete your course. Our courses provide nationally recognized American Heart Association certification, with same-day certification available upon successful course completion.
Frequently Asked Questions
What instruction should you give everyone when the AED is analyzing the heart rhythm?
Tell everyone to move away from the person and ensure nobody touches them during the analysis. This allows the AED to accurately analyze the heart rhythm without interference.
Do you continue compressions while the AED is analyzing?
No. Pause chest compressions when the AED prompts you to stand clear for rhythm analysis. Resume CPR as soon as the device provides the next instruction.
Should you continue giving breaths while the AED analyzes?
No. Pause ventilations when the AED prompts everyone to stand clear. Resume CPR according to the device’s instructions once analysis is complete.
What should you do if the AED says no shock advised?
Resume CPR immediately, beginning with chest compressions. Continue following the AED prompts until emergency medical personnel take over or the person shows clear signs of recovery.
Should you check the person’s pulse while the AED analyzes?
No. Do not interrupt the AED’s analysis to check for a pulse. Wait for the device’s next instruction and follow the recommended resuscitation steps.
What should you do while another rescuer places the AED pads?
While the other rescuer attaches the AED pads, continue CPR, particularly chest compressions, to minimize interruptions. Stop when the AED prompts everyone to stand clear for heart rhythm analysis, and follow the device’s instructions.
