Heffernan describes the incident in the opening pages of her poignant and funny memoir, An Arrow Through The Heart. She was in the middle of a reclining yoga pose on a May morning in 1997 when she suddenly felt a weight on her chest, a sensation that turned into the feeling of a vise, screwing her chest muscles tighter and tighter. She felt cold, and calmly observed her hands which had turned "marble white." "I am having a heart attack," she told her yoga teacher Zoe, who asked her what she wanted her to do.

"I want you to call 911," Heffernan told her teacher. "Tell them I need a cardiac team. Tell them to take me to Mount Auburn Hospital, I need a cardiologist waiting for me. Something is terribly wrong."

As it turned out, something was indeed terribly wrong. Heffernan's left anterior descending (LAD) artery had dissected -- in layperson's terms: torn. No one is sure why. A blood clot had also been unleashed. It was unclear which had occurred first, but the result was that her left ventricle was dying, the chamber that distributes oxygen-rich blood to nourish the body. Although it was extremely risky to move her, her physician and family felt they had no choice but to transfer her to Massachusetts General Hospital, one of Boston's finest teaching hospitals, to undergo an emergency double bypass. Her chances of surviving the operation? About 50-50.

Fortunately, the bypass went well, but during the surgery she developed ventricular tachycardia, or V-tach, as it is nicknamed, a potentially lethal condition in which the heart beats so quickly that it is unable to adequately pump blood throughout the body. Her only option was to have an automatic implantable cardiac defibrillator (an ICD) inserted beneath her skin and attached to her heart with wires. The matchbox-sized device would constantly monitor her heart rate. When it detected a minor arrhythmia -- an irregular heart beat -- it would deliver a small and imperceptible electrical current to her heart, to return it to its normal rhythm. If that didn't work, it would deliver a far greater jolt, which could cause her to momentarily lose consciousness. The whole idea was terrifying to Heffernan, but she knew the device would save her life.

Jeremy Ruskin, M.D., director of Mass General's cardiac arrhythmia service implanted the device between two layers of skin, above her left breast. He told her that she would most likely have to have another procedure to replace the batteries in about five years.

More than five years later, both Heffernan and her ICD are still ticking. Fortunately, her ICD has zapped her only twice, both times during her hospitalization. "It's a Catch-22," says Heffernan, when asked about her relationship with the ICD. "It's my best friend and my constant reminder that I am not safe, that I am sick." She's always conscious of its presence beneath her skin, but finds ways to minimize that awareness, like propping up her left shoulder with a pillow, so there's no pressure on the device as she sleeps. She is also ever vigilant about keeping her distance from the things that could inadvertently interfere with its operation, like cell phones, radio antennas, power lines and airport scanners.

Every year at first, and now every year and a half, Heffernan has to return to Mass General for what she facetiously calls her "date with death" -- her NIPS (noninvasive programmed stimulation) test. That's when her heart is artificially accelerated to determine whether her ICD functions correctly. So far, it has performed perfectly.

Heffernan went on to make a remarkable recovery, thanks to the superb medical care she received as well as the radical changes she made in her life. She and her husband Jack sold their apartment in Cambridge, Massachusetts, and moved full-time to their beloved weekend home in western Maine. She left behind her high-pressure job as a corporate trainer, and now lives what she describes as a stress-free life, which revolves around eating well, a daily 45-minute "power walk," complementary therapies like yoga and acupuncture, and one thing you won't find in a medical textbook.

"It's terribly, terribly important for people to surround themselves with love every single day," says Heffernan. "By love I mean kindness and consideration, generosity, humor, forgiveness."

The alternative therapies have "kept my body unblocked, and energy flowing through it in the ways you want it to flow," says Heffernan. "The body has considerable ability to heal itself, if you leave it open enough."

"Jeremy ((Ruskin) cannot believe how stable I am and how much I've progressed," she says. "I was one of the toughest cases Mass General has ever had. Now I'm working with the heart I have left. I have heart disease and working on that is my primary job."

Heffernan acknowledges that her heart disease will always severely restrict her activities -- she must sleep at least 12 hours a day to function -- but her illness has brought her many gifts as well. In An Arrow Through The Heart, Heffernan writes:

This year of guilty languor; of slow, minute observations of nature; of quiet contemplation; of time to be angry and move through it; of receiving and expressing love -- is required by anyone seriously ill to achieve physical strength and spiritual peace. I am living proof that you cannot separate matters of the heart from the muscle, as scientific research is finally agreeing.''

Heffernan wrote the memoir as a way to help other heart patients along the difficult path to recovery, but also to sound the alarm about the prevalence of heart disease among women, and even young women. She is donating the book's profits to several heart-related organizations.

"As women, we do not take enough care of our own hearts -- both the muscle and the spirit," says Heffernan. "It's extremely hard for women engaged in the prime of their lives -- with babies, husbands, and jobs -- doing all of it -- to say 'no, I come first.' But I think it's important to say 'I come first' for at least half an hour a day."

This patient story may not be typical. Individual symptoms, situations and circumstances vary and response to therapy is not always the same. Please consult your physician or health care provider regarding your condition, treatment or any specific questions regarding your care.