Four hours into a nearly six-hour flight from Seattle to Mexico, Sara Metz felt overly anxious – far more than the usual jitters of a bride-to-be days before her wedding on a beach in Playa del Carmen.

She was watching the movie “Unbroken” when that feeling hit. Thinking maybe the intensity of that story was getting to her, she switched to a Disney film.

It didn’t help. So she headed for the restroom, only to be overcome by a burning in her jaw, upper chest and left arm – a few of the common warning signs of a heart attack, with the added complication of being 30,000 feet in the air.