a pet peeve i have is whenever a character's at a doctor's office and is being auscultated, but the doctor character puts the stethoscope on his chest to listen to his lungs, or on his back to listen to his heart. it's the opposite (chest = heart. back = lungs.)
and it's even better if there's a moment where the show tries to be dramatic and have the doctor go "oh i can't hear a thing!" yeah i wonder why when you try to listen to a dude's heartbeat through his lungs
another similar pet peeve is whenever a character is like "oh my god my heart is racing" and they play a heartbeat sound effect to convey it, but the heart's at like, 80 or 90 beats per minute.
for reference the average resting human heart rate is 60 - 100 beats per minute. 90 beats is just the average fucking pulse for a lot of people. if that's "racing" to you, see a cardiologist immediately.