Rhythms that are not amenable to shock include
Pulseless electrical activity (PEA) is a condition where your heart stops because the electrical activity in your heart is too weak to make your heart beat. When your heart stops, you go into cardiac arrest, and you don't have a pulse. PEA is a “nonshockable” heart rhythm, meaning a defibrillator won't correct it.
There are two types of nonshockable rhythms, pulseless electrical activity (PEA) and asystole.
Heart rhythms associated with cardiac arrest are divided into two groups: shockable rhythms (ventricular fibrillation / pulseless ventricular tachycardia (VF/VT)) and non- shockable rhythms (asystole and pulseless electrical activity (PEA)).
Asystole is a non-shockable rhythm. Therefore, if asystole is noted on the cardiac monitor, no attempt at defibrillation should be made. High-quality CPR should be continued with minimal (less than five seconds) interruption.
'Non-shockable' means that defibrillation is not an effective treatment for these heart rhythms. If an Automated External Defibrillator (AED) detects a non-shockable rhythm, it won't allow the rescuer to deliver an electrical shock to the victim.
Pulseless electrical activity (PEA) and asystole are related cardiac rhythms in that they are both life-threatening and unshockable cardiac rhythms. Asystole is a flat-line ECG (Figure 27). There may be a subtle movement away from baseline (drifting flat-line), but there is no perceptible cardiac electrical activity.
The most common shockable rhythms associated with cardiac arrest are pulseless ventricular tachycardia and ventricular fibrillation.
You will need to be able to recognize the four lethal rhythms. Asystole, Ventricle Tachycardia (VT), Ventricle Fibrillation (VF), and Polymorphic Ventricle Tachycardia (Torsade de pointes). Use this study guide and other resource books to review ECG interpretation.
Why not shock a PEA Arrest? In a PEA arrest, similar to Asystole, the heart doesn't have the means to use the shock you're sending it because the primary cause has yet to be corrected. Shocking a heart in PEA arrest is like kicking a comatose patient in the abdomen (which we do not recommend).
In PEA, the heart's electrical activity is too weak to continue pumping blood throughout the body. Like with Asystole, an AED will not correct this arrhythmia, and CPR should be administered as soon as possible to provide the best patient outcome.
Pulseless VT is a medical emergency that requires immediate defibrillation. The energy of 150-200 J on biphasic and 360 J on monophasic defibrillator should be used. Delaying defibrillation of pulseless VT dramatically decreases the survival rate.
Shockable Rhythms: Ventricular Tachycardia, Ventricular Fibrillation, Supraventricular Tachycardia. Much of Advanced Cardiac Life Support (ACLS) is about determining the right medication to use at the appropriate time and deciding when to defibrillate.
When adrenaline is used, it should be used as soon as possible when the cardiac arrest rhythm is non-shockable, and after 3 defibrillation attempts for a shockable cardiac arrest rhythm.
Ventricular tachycardia (v-tach) is the other shockable rhythm that can cause cardiac arrest. In this condition, the ventricle's pacemakers don't receive impulses from the heart's primary pacemakers and begin to fire rapidly to compensate.
The only two drugs recommended or acceptable by the American Heart Association (AHA) for adults in asystole are epinephrine and vasopressin. Atropine is no longer recommended for young children and infants since 2005, and for adults since 2010 for pulseless electrical activity (PEA) and asystole.
Death is not a linear process. New research finds that it's fairly common for the heart to restart — usually just for a beat or two — after a person initially flatlines. No one in the study, which took place in intensive care units (ICUs) in three countries, survived or even regained consciousness.
Children or adults who develop cardiac arrest caused by a slowing of the heart rate (bradycardia) or cardiac standstill (asystole) cannot be treated with an AED. These rhythms do not respond to electric shocks, so the AED will not allow a shock to be activated and standard CPR measures should be performed.
Asystole (ay-sis-stuh-lee) is when there's no electricity or movement in your heart. That means you don't have a heartbeat. It's also known as flatline. That's because doctors check the rhythm of your heart with a machine called an electrocardiogram -- also called an ECG or EKG.
According to International Liaison Committee on Resuscitation (ILCOR), pulseless electrical activity refers to any rhythm that occurs without a detectable pulse; however, it excludes ventricular fibrillation (VF) and ventricular tachycardia (VT). Asystole is the more life-threatening arrhythmia.
Ventricular fibrillation is the most common cause of sudden cardiac arrest (SCA) and is fatal if not treated within a few minutes. Slow heart rhythms occur when the hearts normal pacemaker fails or when there is a conduction block within the conduction pathways.
You will learn about Premature Ventricular Contractions, Ventricular Tachycardia, Ventricular Fibrillation, Pulseless Electrical Activity, Agonal Rhythms, and Asystole.
Ventricular fibrillation (V-fib) is the most serious arrhythmia and is a life threatening medical emergency. Disordered electrical signals in the heart cause the ventricles to quiver instead of pumping normally. This quiver is known as fibrillation.