Harvard Mental Health Letter

Commentary: Strains on the heart


Strains on the heart

In the 1950s, following a heart attack, doctors would warn families to take care not to upset the convalescing patient. Some people who grew up in that era report being told, "Don't make your father angry. He could have another heart attack!"

Back then, cardiologists also instructed patients to rest completely following a heart attack. Today doctors advise their patients to get regular exercise after a coronary event. And you won't hear advice to tiptoe around a heart attack victim anymore. Occasional temper flares are probably not particularly dangerous. But there is more and more evidence that chronic psychological stresses, both at home and at work, do take their toll.

In a study published in October 2007 in the Archives of Internal Medicine, researchers in England showed that when intimate relationships are particularly negative, they affect coronary heart disease outcomes for the worse.

Data were gathered on more than 9,000 British civil servants who had participated in a large, long-term study examining how health is affected by psychosocial and economic factors. A questionnaire assessed, among other things, the quality of their close relationships. Participants reported on the level of emotional and practical support they received and on how much "negativity" they experienced in their primary relationships (for example, that it was a cause of worry, problems, or stress). Results were correlated with subjects' medical outcomes over a period of 12 years.

People reporting significant negativity in their close relationship were about a third more likely to have a cardiac event — a heart attack or severe chest pain — during the study period. The researchers examined a long list of relevant variables and potential cardiac risk factors: the subjects' temperament, age, gender, marital status, type of employment, job stress, sources of support, and health behaviors such as smoking, drinking, diet, and exercise. The correlation between relationship negativity and cardiac risk held up even when all other risk factors were taken into account.

In the same month, the Journal of the American Medical Association published the results of a large Canadian study that examined the effect of returning to work after a first heart attack. The authors used an increasingly popular definition of job strain that combines two factors: psychological demand and latitude. Demand increases as the amount and intellectual difficulty of the work goes up and the time to do it in goes down. Latitude is the freedom to use creativity and talent to make decisions about how and when to do work. As you might expect, the worst job strain occurs when high demand is combined with low latitude.

The study found that the higher the job strain, and the longer it lasted, the greater the increase in cardiac risk. These results remained significant even after the researchers analyzed the influence of more than two dozen other variables.

It's not yet clear how strain translates into worse cardiac health. Experts suggest that chronic stress could aggravate inflammation in coronary arteries, leading to the blood clots that trigger a heart attack. Alternatively, stress makes it harder to sustain healthy habits that keep cardiovascular disease at bay.

Whatever the cause, the link between stress and heart disease is hard to ignore. And while an occasional emotional outburst is unpleasant, the real problem is the drip of chronic strain in daily life. The research suggests that anything people can do to reduce this kind of stress would not only improve their quality of life (which should be reason enough on its own), but also may extend their lives.

— Michael Craig Miller, M.D.Editor in Chief, Harvard Mental Health Letter