The human body's most remarkable and often most misunderstood organ is the heart. Yet heart-related ailments remain among the nation's deadliest illnesses, with cardiovascular disease claiming nearly 800,000 lives a year. Learn what it takes to become heart-healthy in this compelling series from public TV, filmed in high-definition. Hear the personal stories of those patients most at risk, but least likely to know why.

Program 1: Endlessly Beating Endlessly Beating examines the heart as a muscle - pumping more than 100,000 times a day, pushing approximately five quarts of blood on an endless path that deliver oxygen to every cell in the human body. This hour tells the story of the normal heart through the histories of three people with end-stage heart failure, where a pump may be a temporary remedy, but in the long term, a transplant is often a necessity.

Program 2: The Spark of Life The Spark of Life looks at the physiological electrical mechanisms that keep a heart beating regularly and efficiently - and what happens when this most essential rhythm of life goes awry. The program takes viewers from New York to Brazil, and into the lives of patients who suffer similar symptoms that actually signal different disorders. The range of treatment options - if not cures -is startling.

Program 3: The Silent Killer The Silent Killer focuses on atherosclerosis, the silent blockage of the coronary arteries, which can trigger devastating and sometimes fatal heart attacks. The key is to recognize the risk factors that feed the disease and control them before it's too late. This program follows patients through potentially lifesaving interventions, but ultimately, focuses on the challenges of living with and preventing a disease for which there is no cure.