McSelva - So sorry for your loss - while we were there we heard of another heart attack while someone was snorkelling. I carried the numbers for 2 local Doctor's with me while we were there - my husband has high blood pressure - high cholesterol and sugar diabetes - certainly a recipe for disaster. I also have insurance .
I wonder if a Doctor could have been called , if he might have been able to do something for your mother until the ambulance got there. One day while we were there I was certain I saw two ambulances on the same day within a short while of each other. Not sure if one was the local one - van shape and the other could have come from somewhere else - it was more like your typical square type.
Thoughts and prayers for you and your family.