Depression may be lethal for the faint of heart. In a study that gives new meaning to "down and out," a St. Louis researcher reports that depressed people with heart disease are eight times more likely to develop a deadly heart rhythm than heart patients who aren't blue.
Though scientists have long acknowledged that depressed heart patients are more likely to die of heart attacks, no one had been able to come up with an explanation until 1994, when psychologist Robert Carney, Ph.D., found they were prone to ventricular tachycardia (VT), a speeding of the heart rate.
"This is the rhythm that occurs most often before sudden cardiac death," says Carney, of Washington University. Of 103 patients with coronary artery disease he studied, 20 percent were clinically depressed. And 24 percent of the depressed patients experienced VT episodes during a 24-hour period of monitoring.
Not unlike feelings of anger, anxiety, and excitement, depression can kick the sympathetic nervous system, which controls heart rhythm, into high gear; the heart races. But while anger and anxiety are usually fleeting, depression is more durable. Hence people who are depressed are at greater risk for abnormal heart rhythms.
