It’s the last resort (besides selling your soul) when your best friend/family member/love interest has died: CPR. After all, it’s obviously the best trick medicine can buy. After a few breaths and tense moments, the presumed dead wakes sputtering and coughing, but otherwise perfectly okay.
Except that’s totally wrong.
Why this is bad: This is not how the world works. This is not how CPR works. If a person’s heart has actually stopped, the only way to get it going again is with an electric shock. If you performed CPR in real life, you would need to perform CPR until medical professionals arrived – and even then, it’s gonna be hard to get them back. This doesn’t even cover he broken ribs, brain damage, and other potential side effects of having your heart stop. Not only is this overused trope straight up wrong, it’s often used as a cheap device for momentary drama.
How you can fix it: Do research on medicine and first aid. Don’t just assume that because that’s how it’s been seen in movies that that’s how it happens in real life. If readers get to the point in your story where someone is performing CPR, there isn’t any real danger for them; they’re pretty positive the “dead” character is going to be just fine. In fact, using the reality of CPR and stopped hearts would work to your advantage here, because it’s much more tense than just sputtering awake. Actions need consequences, and these consequences shouldn’t disappear after ten seconds of mouth breathing.
Bottom Line: Do your research! Just because it’s convenient for the plot does not mean you can glaze over reality.