National Geographic : 1956 Jul
Hunting the Heartbeat of a Whale A Scientific Expedition Sails a Lonely Mexican Lagoon in Search of Clues to the Mysteries of the Human Heart BY PAUL DUDLEY WHITE, M.D., WITH SAMUEL W. MATTHEWS «" 1 7HEN I first tried animal experi mentation for the purpose of dis Scovering the motions and functions of the heart by actual inspection and not by other people's books," wrote Dr. William Harvey in 1628, "I found it so truly difficult that I almost believed with Fracastorius,* that the motion of the heart was to be under stood by God alone." Thus begins one of the most celebrated works on the human heart, Harvey's De Motu Cordis. Many times have these words re turned to my mind during a lifetime of studying-often with animals-that most wonderful and mysterious of mechanisms, the heart. Pulse of a 30-ton Patient Early this year we embarked upon an ad venture that brought back Harvey's opening sentence with redoubled meaning. Our ex pedition, with all the extraordinary equip ment of 20th-century science at its command, still found "animal experimentation... so truly difficult" that we nearly met disaster. We sailed into the lonely waters of Mexico's Scammon Lagoon, halfway down the Pacific coast of Baja California, seeking a strange goal (map, page 54). We were going to try to record the heartbeat of a whale. For our unusual venture the National Geo graphic Society, the Douglas Aircraft Com pany, the Sanborn Company of Cambridge, Massachusetts, makers of our sensitive heart recorders, and many other organizations and people had given generous aid. Before the expedition was over, we learned why the California gray whale long ago was nicknamed "devilfish." We nearly lost a boat, stove in by a mother guarding her newborn calf. Six of our party came all too close to the lashing tail of the angry giant. In the end we fell short of our goal. But we knew more about the difficulty of measur ing the heart impulses of an animal "patient" 40 feet long and weighing some 30 tons. In setting forth with such an aim, we were really searching for clues to mysteries of the human heart. * Physician-poet of Verona, 1483-1553. Both whale and man are mammals. But whereas man's heart is roughly the size of his two fists, the heart of an adult gray whale would overflow a bushel basket and tip the scales at more than 250 pounds. Human hearts beat 50 to 90 times a minute. But the heart of a large whale pumps very slowly-perhaps fewer than 10 times a minute. No one knows exactly, for the pulse of earth's most ponderous creature never has been taken satisfactorily. To do so has been my dream of 40 years. In 1916 we dissected the heart of a sperm whale caught in the Atlantic by one of the last of the New Bedford whaling ships. Microscopic study revealed an intricate and beautiful structure. Some of the largest tissue cells ever measured were found there. Spe cialized bands of muscle, conductors of the heart's electrical currents, were seemingly better perfected than in any other mammal. In the intervening 40 years we have made electrocardiograms of mice and circus ele phants. The mouse's heart, we found, beats 500 to 600 times a minute, while an elephant's pulse thumps only 35 to 40 times. The larger the heart, the slower its beat. The mammalian heart contracts and beats in its unfaltering pulse because of electricity it generates within itself. Its driving im pulse or current, measuring no more than a thousandth of a volt in the human, begins in the so-called "pacemaker" of the heart. Expedition Heartbeat Forty years ago a young Boston cardiologist, Dr. Paul D. White, published the first detailed scientific description of a whale's heart. Since then, seeking greater understanding of heart structure and pulsa tion, he has studied living mammals ranging from mice to circus elephants and the beluga whale. Early in 1956 a National Geographic Society re search grant assisted Dr. White and two colleagues, Dr. Robert L. King and James L. Jenks, Jr., in an attempt to make an electrocardiogram of a California gray whale in its breeding waters along Mexico's Baja California peninsula. Dr. White is President Eisenhower's heart consult ant. Dr. King, an associate and cardiologist of the Mason Clinic in Seattle, Washington, was president of the American Heart Association in 1953-54. Mr. Jenks is president of the Sanborn Company of Cam bridge, Massachusetts, manufacturers of electrocardi ographs and other precision instruments.