John is a 54 year old high school AP physics teacher. One spring morning while walking his dog around the block, John developed the sudden onset of crushing chest pain. So severe was the attack that he collapsed in front of his neighbour’s house. Hearing the dog’s frantic barking, the neighbour rushed out, saw that John was in need of immediate medical attention, and ran to call 911. Within minutes John was taken directly to the local hospital by an ambulance. Whisked into the emergency room, a doctor performed an electrocardiogram on John, then diagnosed him as having had a myocardial infarction. (Commonly referred to as a heart attack, this is when heart muscle dies because a blocked artery causes an interruption in blood supply to the heart.) John was then quickly brought to a catheterization laboratory. There, a cardiologist threaded a small catheter into the major blood vessel leading into the blocked artery in John’s heart. By inflating a tiny balloon, the doctor opened the blocked passage, thereby restoring blood flow to John’s heart.

Thanks to that prompt, precise, and practiced attention, John survived, going on to do quite well after what was a near-fatal episode. Although it was a happy ending indeed, the fact that John and far too many others throughout the world suffer such attacks in the first place is a phenomenon science is working to minimize.