Our hearts beat about 100,000 times every day, pumping our blood nearly 12,000 miles: the equivalent of crossing the U.S. from coast to coast four times. Today we'll find out how our most vital organ works, why it sometimes fails, and what we can do to keep it healthy. Send us your questions for Dr. Peter Libby, Chief of Cardiovascular Medicine at the Brigham and Women’s Hospital in Boston, Professor at Harvard Medical School, and the chief medical advisor for the PBS series “The Mysterious Heart."

Call us at 212-433-WNYC or post your questions and comments here.

“The Mysterious Human Heart” airs nationwide on Monday, October 22 at 9pm (check local listings).

Find more information, use interactive features, and view all the complete episodes of the series online here.