It's a question that some patients are afraid to ask: What are my chances of dying on the operating table?

Now, believe it or not, there's an app for that.

"My Heart Surgery Risk" was created by Dr. Edward Bender, a heart surgeon in Cape Girardeau, Mo. All you have to do is answer a series of yes-or-no questions on your iPhone or iPad, and it calculates your risk of making it through heart bypass surgery.

Bender said the app, which is free on the Apple iTunes store, was adapted from the website of the Society of Thoracic Surgeons, which has its own "risk calculator" based on hundreds of thousands of patients.

Bender said his contribution was to simplify the calculator so it's easy for laymen to use.

"I felt that the patients and their family members deserve access to the same sort of information that the physicians do," he said.

As operations go, heart bypass surgery is relatively safe, Bender says. But the risks -- having a stroke, ending up on a breathing machine, dying -- go up or down depending on gender, age, weight and other factors. (Do you get short of breath walking? Do you take blood pressure drugs?)

The app shouldn't replace a heart-to-heart talk with your surgeon, he says; it's meant to start one.

Dr. Frazier Eales, a heart surgeon at Abbott Northwestern Hospital in Minneapolis, hadn't seen the app, but he loved the idea. "I think anything that puts valid information in the hands of patients is worthwhile," he said.

Many patients facing surgery don't have much time to ponder the potential downsides, he said, and some are hesitant to ask. Others want to know everything -- and end up in a Google-induced state of confusion.

An app that's accurate and simple to use can jump-start an important discussion, he said.

Bender says that's how apps will change medicine.

"People will come to their physicians with much more information," he said, "and I think that will allow for a better patient experience."