Medicine: Work & the Heart

What does work do to the heart? Does mental or physical exertion have the greater effect? And what about hearts weakened by disease? In a search for up-to-date answers to these questions—matters of life and death to increasing numbers (mostly men) in highly developed countries—Western Reserve University held a postgraduate course for physicians in Cleveland last week. The consensus: work is good for the heart; physical work is best; and most heart-disease victims should be trained to do more of it.

“If we start with a healthy heart,” said Boston’s Dr. Paul Dudley White, 76, elder statesman of cardiology, “physical labor or exercise apparently helps to keep it healthy. There is no evidence, that mental work per se causes heart disease, although in excess it may lead to neglect of proper health habits, and thus perhaps favor the early development of heart disease. The best antidote for the harmful effects of intensive mental work is vigorous physical labor or exercise.”

Engine or Computer? Underlying all arguments about mental v. physical work, said Cornell University’s Dr. Lawrence E. Hinkle Jr., is the question. “What is work?” Using the physicist’s definition,”A force acting through a distance,” work done by the heart could be measured in relation to the amount of coal a man shovels, or how much tennis he plays, or how far he walks. But man’s nervous system is a data-processing mechanism that regulates the rate and rhythm of the heart without regard to the volume or energy of the signals it receives. Bright sunlight or a thunderclap may have no effect on the heart; a vital message read in semidarkness or a whisper that “A.T. & T. has fallen 30 points” may send the heart racing faster than it would during a hard set of tennis.

For the physician, said Dr. Hinkle, the most workable definition of work is Tom Sawyer’s: “Work is what a body is obliged to do, and play consists of whatever a body is not obliged to do.” And while there is evidence that the demands of the job may affect the health of the man, it is equally true that the nature of the man is an important factor in determining the extent to which the job is demanding. “The demands of the job.” Dr. Hinkle said, “are those perceived in it by the individual.”

Not in the Job. That a surgeon performing a delicate operation may work his heart as hard as any factory hand was demonstrated in ingenious research reported by Western Reserve’s Dr. Herman K. Hellerstein. Investigators rigged up 39 surgeons with electrodes for continuous electrocardiograph records and a cuff for blood pressure readings, fitted the doctors with masks to monitor their oxygen consumption, and conducted a battery of other tests, both before and after the operations. Though the surgeons may have done nothing more strenuous than cutting and tying small blood vessels, they expended, on the average, as much energy as welders or drill-press operators. At the climax of the operations, their hearts raced to an average of 118 beats per minute, with one surgeon logging 155.

By other measurements, the surgeons fell into two distinct groups; 23 showed no change in blood pressure, while 16 had marked rises. And neatly tying together the theories of Drs. White and Hinkle, the Western Reserve researchers found that the surgeons who expended least excess energy were the best physical specimens. In general they were the ones who showed, on psychological tests, as least likely to overreact. Concluded Dr. Hellerstein: “The circulatory response depends upon something other than the requirements of the work. This ‘something’ resides in the individual and not in the job.”