An irregular heart rhythm can cause serious health problems. In the case of cardiac arrest, a shock from an automated external defibrillator (AED) can kickstart the heart until further medical assistance arrives. But only shockable heart rhythms respond to electric shock — and not all heart rhythms are shockable.
Studies show that if performed immediately after a person has gone into cardiac arrest, CPR can double or even triple his or her chances of survival. And while the AED itself is designed to detect shockable heart rhythms from non-shockable ones, it’s worth knowing the hallmarks of the different irregular heart rhythms if you’re ever faced with an emergency.
Read on to learn the difference between shockable versus non-shockable heart rhythms and what CPR givers can do when confronted with these types of cardiac arrests.
Automated External Defibrillators
You’ll find AEDs in thousands of public spaces across the country, which are to be used in the event of a cardiac arrest. When someone’s heart stops beating properly and falls into an unusual rhythm, this is classed as cardiac arrest. AEDs can restore a normal rhythm but don’t work on every type of irregular heart rhythm.
The AED will detect whether a rhythm is “shockable.” It will administer an electrical current to patients with shockable heart rhythms, and it will not shock in the case of a non-shockable heart rhythm.
Regular vs. Irregular Heart Rhythms
In adults, a “normal” resting heart rate ranges from 60 to 100 beats per minute, according to Mayo Clinic. Normally, the heart beats in a regular fashion and keeps a certain rhythm. An irregular heart rhythm, on the other hand, happens when electrical impulses in the heart become too fast, too slow, or irregular.
Some irregular heart rhythms are considered a common byproduct of aging and are known as arrhythmias. Further, some irregular rhythms are shockable heart rhythms, which can be corrected by AED-administered shocks, while others, unfortunately, can not.
Types of Irregular Heart Rhythms
Not all irregular heart rhythms will result in cardiac arrest or require the use of an AED. There are two main types of irregular non-shockable heart rhythms that present themselves through cardiac arrest and should not be treated with an AED.
- Pulseless electrical activity (PEA). During PEA, the heart stops because its electrical activity is too weak to make the heart beat, thus sending the person into cardiac arrest. When this occurs, the victim will no longer have a detectable pulse.
- Asystole, commonly known as “flat lining,” means there is no electrical or mechanical heart activity to detect. Patients with asystole (non-shockable) heart rhythms have a very poor chance of survival, with only 10% surviving to the point of hospital admission and 2% surviving to the point of hospital discharge, according to studies.
On the other hand, irregular shockable heart rhythms can be treated by a shock via an AED. In these cases, an AED shock can correct the heart’s rhythm, allow the heart to get more oxygen to the brain, and give the patient more time before medical assistance arrives. There are three forms of shockable heart rhythms:
- Ventricular tachycardia, also known as V-Tach, often responds well to defibrillation. Most people who suffer V-Tach are unconscious and without a pulse. In this case, the heart can be “reset” by using an AED. Multiple shocks may be necessary to treat this type of heart rhythm.
- Ventricular fibrillation, or V-Fib, is a common cause of cardiac arrest and is best described as the heart “quivering,” which means no blood is pumped out of the heart. Often mistaken for asystole, V-Fib can be corrected by AED shocks.
- Supraventricular tachycardia, or SVT, occurs when the heart is beating faster than 150 beats per minute. Symptoms vary from patient to patient, so it’s difficult to diagnose. Patients who are unstable or do not respond to other treatment may benefit from a shock from an AED.
If you’re worried about accidentally using an AED on a victim with a non-shockable heart rhythm, know that AEDs can distinguish shockable from non-shockable heart rhythms and will only administer a shock to someone with a shockable rhythm.
When to Use an AED & Where to Find One
To know when to use an AED, attach it to the person experiencing cardiac arrest. Remove their clothes, making sure their chest is dry, and the AED will detect whether a shock may be administered to the patient. The AED won’t shock the patient unless it detects one of the shockable heart rhythms.
AEDs are typically found in public spaces like leisure centers, shopping malls, and public buildings. They’ll be marked with a green “AED” sign and a graphic of a white heart being split by a lightning bolt. You should be able to access them 24 hours a day.
Although not all cardiac arrests can be helped by administering an AED shock, everyone can benefit from knowing the difference between shockable and non-shockable heart rhythms and how and when to use an AED. Contact us today to learn more about how ProTrainings can help you make getting your staff CPR certified easier and more efficient.