Human Body
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What Happens to Your Body When a Defibrillator Is Used on You

Updated November 5, 2019 20k views10 items

Defibrillation is a wildly misunderstood process. Hollywood, as Ken Jennings notes, is way behind the times on this. The paddles? Yelling “clear”? “Jump starting” flat-lining patients like they’re an old jalopy? Please. These days, automated defibrillation using sticky pads is where it’s at, and defibrillation is the last thing flat-lining patients need. So what is being defibrillated like in the real world? What happens to your body when a defibrillator is used on you?

What defibrillators feel like varies depending on which kind is used. The implanted kind, for example, “fire” when you’re conscious, and people say they’re intensely painful. Patients are haunted by the pain they experience with these things, even if they ultimately agree that they’re worth it. The old school paddles, however, are never used on conscious patients and the automated kind “sense” whether or not you need them before they fire. That said, science tells us that the pain of all defibrillation, while unique on a case-by-case basis—all pain is subjective, eh?—is essentially the same (i.e., it sucks). Read on to find out more about what defibrillation really feels like. Clear!

  • Your Skeletal Muscles Contract

    The American Heart Association says that defibrillating shocks “typically cause a powerful tetanic contraction of skeletal muscles.” Translation: muscles near your skeleton—most importantly the ribs in this case—go through a powerful, sustained contraction. Since CPR and defibrillation go hand-in-hand, it’s important for medical professionals to time their chest compressions correctly. Otherwise, as the AHA notes, the victim could suffer rib fractures and the “rescuer” could suffer wrist or arm fractures.

  • 'As If Someone Had Shoved Metal Doors Violently Into My Back'

    Photo: DiegoJ.Ramirez / flickr / CC-BY 2.0

    Jackie Todd told The Atlantic in 2015 that when she was 14, her implanted defibrillator fired after she ran across her high school campus to catch a screening of the second Harry Potter movie and overworked her heart. The implant saved her life, but felt like “someone had shoved metal doors violently into [her] back,” knocking the wind out of her. To make things worse, the first shock sent her heart rate skyrocketing, so another jolt was automatically administered. The second one made her pass out: “Her vision went white, her knees buckled, and she collapsed at the top of a stairwell, unconscious.”

  • Electrolytes Are Forced Out of Your Cells

    Electrolytes aren’t just what plants crave, they also provide the “shock” that causes the heart muscle to naturally contract. As Gizmodo explains, the shock of defibrillation is used to force electrolytes out of your heart’s cells when they’re “fibrillating,” because those particular electrolytes aren’t coming from the right place: the Sinoatrial node. They’re instead coming from “countless other cells within the heart,” which contributes to the chaos. Defibrillation is an attempt to force out the wrong electrolytes so “the heart’s normal operation of electrolytes passing across the cell membranes in an organized fashion will take over again.” This also explains why trying to “jump start” a flat-lining or “asystole” heart via defibrillation is useless: there are no electrolytes in the cells in that state to force out.

  • 'More Sudden and Frightening Than It Is Painful'

    Photo: joejukes / flickr / CC-BY 2.0

    Studies say that most patients with implanted defibrillators say the shock is “more sudden and frightening than it is painful,” but it’s still pretty damn painful. It’s been called “a kick to the chest” and “a jolt from an electric fence,” for example. On a common pain scale, patients rate it a 6 out of 10, which doesn’t sound too bad, except for one small detail: 10 represents the “worst pain imaginable.” Ultimately, most patients agree that the pain level is “appropriate” considering it stopped “a life-threatening arrhythmia.”