Updated: Jul 7, 2020
This is the most annoying medical error in film and writing... here's what a flatline actually means.
Okay, people with a creative mind. You have a character. Your character dies in the hospital, or on the street, or in their house, or anywhere (OH NO!) and then they are valiantly brought back to life at the brink of continuing on their merry way to the light or to hell (whatever, it's your story).
Great plot device. It's an excellent way to bring about character development, superheroes or anything in between. Except the one tad little error that is made in absolutely everything- shocking asystole (or flatline).
You don't do it. It does nothing. Pumping electricity through a dead heart does nothing. The heart muscle stays dead.
So here's a little lesson in ECG's, shockable rhythms, and when to shock in prehospital or in the hospital setting (brought to you by your friendly neighbourhood paramedic).
Heart Anatomy for beginners:
The heart has 4 chambers. Two Atrium (top parts) and two ventricles (bottom parts). Blood goes through the heart as follows: Right atrium fills with deoxygenated blood, the atriums pump, filling the right ventricle with deoygenated blood, the ventricles pump, sending the deoxygenated blood to the lungs where it's oxygenated. The left atrium fills with oxygenated blood, the atriums pump, the left ventricle is filled with oxygenated blood, the ventricles pump, the oxygenated blood is sent throughout the body.
The thump-thump of a heartbeat. Atriums pump - pause - ventricles pump. This keeps you alive and your fingers and toes from turning blue.
Okay, a little more anatomy. The heart is a pretty cool muscle, and every single cell in it produces electricity. So an ECG (or EKG, doesn't matter) is just measuring the electrical conductivity of all the cells of the heart.
That's all an ECG shows - what the electricity in your heart is doing. Now, your atriums could not be filling properly and jiggling a bit (a-fib), or your could be having an electrical block between the atriums and ventricles (first, second or third degree blocks), or you could have a dead piece of your heart (myocardial infarction, ie a heart attack). All of this is shown on an ECG. How this is shown is really not needed but is super interesting. Take an online ACLS course to learn.
What does asystole mean? Flatline. Dead. No electricity.
So why do we shock?
The heart is shocked as a sort of reset to the electricity in the cells. They can be going way too fast (supraventricular tachycardia: SVT ), the ventricles could only be beating too fast (ventricular tachycardia: v-tach) or the ventricles could be jiggling and not doing anything (ventricular fibrillation: v-fib). Those we shock. The electricity could reset the heart into a normal rhythm. V-fib, v-tach, and SVT are shockable rhythms. If the heart is going too slow or too fast, we can cardiovert with a lower dose of electricity to reset the heart.
Now... why do they always yell "CODE BLACK!" in the movies and shock the flatline?
Well, v-fib and v-tach can be pulseless. That means that you're dead. You have no pulse. You are not living. So, your heart is jiggling fast, not pumping blood, and your brain is dying. That's why we shock in codes.
We are not necromancers. If your heart is dead, it's dead. We can give a dose of epinephrine (epic-pen) to try and restart the heart. That rarely results in a save, and if it does there's a lot of new evidence saying that there's far more likelihood of brain damage post-code.
So please, do not shock asystole. I know it's dramatic... but just like a case of condoms at a lesbian bar, it's useless.