During a heart attack, every minute counts. Paramedics use different tests, like an electrocardiogram, to diagnose a heart attack while racing a patient to the hospital.

"Basically, they want to find out the patient's risk factors, history, clinical presentation, and vital signs to determine what medications we're going to give," said paramedic instructor Geoffrey Smith.

Some paramedics in San Antonio, Texas, are the first in the country to add a saliva test and an analyzer called a "lab-on-a chip" to their on-board "test kit."

"We're primarily looking at proteins in saliva and to see if a group of proteins would help us diagnose a heart attack," said Dr. Spencer Redding, a dentist and researcher.

After paramedics get the saliva sample, it's put on a card that slides into an analyzer. The analyzer has a biosensor chip that detects the heart attack proteins that Redding's test hunts down.

"We can take a very small sample of fluid like saliva, process it in a small chip in an analyzer and do 40 to 50 to 60 tests at one time," said Redding.

Ambulance results are fast, and will likely translate into faster cardiac care once the patient makes it to the hospital.

"So, instead of having to wait another 45 minutes to an hour longer in the emergency room to get the blood tests, they already have that information when the patient comes in the emergency room and they can direct their care appropriately," he said.

About a dozen paramedics in San Antonio are being trained with this groundbreaking technology. If all goes well, we could see it nationwide within three to five years.

The lab-on-a-chip analyzer was developed by researchers at the University of Texas in Austin.