The Circulatory System, the Heart, and Blood

W hen the heart stops beating—that is to say, stops pumping blood—for longer than a couple of minutes, we stop living. But the heart, fortunately, is extremely sturdy. It is also simple in construction, capable of operating at a great many different speeds, in many cases self-repairing if damaged, and probably the one continuously operating automatic pump that we could, with any confidence, expect to last 70 years or longer.

These simple facts tend to be forgotten today, in what is probably the most heart-conscious era in history. True, heart disease, along with cancer, is statistically one of today's major killers. But we should remember two circumstances: not until about 50 years ago did deaths from heart disease begin to be accurately recognized and reported; second, with longer and longer life spans, it becomes more likely that a nonstop vital organ like the heart will simply wear out. Heart transplants, open heart surgery, and artificial heart parts—often reported sensationally in the public media—have also conditioned us to think of our hearts as terribly vulnerable, rather delicate, a bit inadequate to their tasks, and quite open to improvement.

Advances in heart surgery do, indeed, hold greater promise for persons whose hearts had been considered, until now, irreversibly damaged or diseased. But the great attention accorded such miracles of medicine tends to obscure the humdrum, day-in-day-out, low-key drama performed for a lifetime by a healthy, uncomplaining heart.