I'm assuming the writers were paying homage to
The Premature Burial with Maggie's diagnosis. Poe's narrator suffers from catalepsy (the medical term for catatonic seizures), which causes his heartbeat to be barely perceptible and his breathing to become "torpid, unequal, and vacillating;" thus his fear of being buried alive, yikes!
he says the nurse is a competant professional (who had trouble locating Maggie's heart)
Alondra, I paid closer attention to the replay of the nurse placing her stethoscope on the left side of Maggie's chest. She placed it over the lung, beginning at the top, presumably to listen for breath sounds before checking for heart tones. It's exactly what any competent nurse would do if there were no obvious signs of breathing nor a palpable pulse.
BTW, please check out this post:
... I realize that these recent Robservations aren't the most detailed out of RobinV's summaries, yet occasionally the recaps by posters are repeating the same information they contain: ...
Thanks!