LOS ANGELES (CBSLA.com) — The number one killer in America is heart disease.

Now there’s a simple new test that possibly predicts heart disease years in advance not by looking at your heart, but your fingers instead.

KCAL9’s Juan Fernandez spoke to Dr. Chris Renna of LifeSpan Medicine in Santa Monica to find out how the test works.

“Endothelial function is the bomb. That’s the money,” he said.

Blood vessel health can be easily checked with the EndoPat test, according to Dr. Renna.

He showed Fernandez various charts showing patients with varying results.

“You can see endothelial dysfunction in 30 year olds. You can prevent a potential lifetime of distress and misery by correcting that,” he said.

Ed Murphy is being treated by another doctor. While he doesn’t have any heart disease symptoms, he wanted to know if he was headed down the wrong path.

“I think it’s time to keep an eye on things because after 50, everything goes down hill,” Murphy said.

During Murphy’s EndoPat test, doctors placed blood flow sensors on a finger on each hand. Then a blood pressure cuff was inflated to stop blood flow to one hand.

After five minutes, the cuff was deflated, and the sensors measured recovering blood flow.

In a normal patient, blood flow stops when the cuff is inflated, but the patient experiences a rebound surge in blood flow when it’s deflated. In an abnormal test, blood flow only recovers to what it was before the stoppage. This signals potential trouble in the heart.

“If the results are not normal, you have to do lifestyle modifications. Lifestyle changes are in order to make them normal,” Dr. Renna saud.

Simple changes in weight, diet, exercise and perhaps medication can hopefully restore normal blood vessel function and prevent possible heart attacks or strokes.