Stress worsens arrhythmias, increasing risk of sudden death

Stress is as much a part of daily life as traffic jams and taxes. For those susceptible to arrhythmia, an abnormal heart rhythm, psychological stress can be especially dangerous because according to a Yale study, it alters the characteristics of the arrhythmias, making them potentially deadly.

The study sought to explore how mental duress affects the hearts of patients with implantable cardioverter-defibrillators. Using a programmed stimulation system, the researchers triggered arrhythmias as part of routine testing of the defibrillators. Then they induced mental stress by asking the patients to discuss upsetting or frustrating situations and by grilling them with rapid-fire arithmetic problems, again triggering arrhythmias with programmed stimulation. The results, published in the January 18 issue of Circulation, a journal of the American Heart Association, showed that not only did programmed stimulation during mental stress induce faster arrhythmias than those induced during rest, but these arrhythmias were also more difficult to terminate.

According to cardiologist Rachel J. Lampert, M.D., assistant professor of medicine and the study’s principal investigator, “This shows that mental stress situations that raise adrenaline levels alter the behavior of arrhythmic circuits, making them potentially more deadly.” Lampert hopes to develop preventive therapies and prognostic tools for at-risk patients. “For people with arrhythmias,” she said, “interventions aimed at blocking responses to stress may be helpful.”