"It's an important study because we are beginning to understand how anger and other types of mental stress can trigger potentially lethal ventricular arrhythmias, especially among patients with structural heart abnormalities," Dr. Rachel Lampert of the Yale University School of Medicine in New Haven, Conn., said in a statement.
Researchers studied 62 patients with implantable cardioverter-defibrillators who underwent monitoring during a mental stress test. Patients who had coronary artery disease or dilated cardiomyopathy -- a condition in which the heart muscles are enlarged -- and a standard indication for implantable cardioverter-defibrillators were recruited from the Yale Electrophysiology practice.
The mental stress test asked patients to recall a recent situation in which they were angry or aggravated. Patients were tracked for a mean of 37 months.
"In this study, we found patients with higher levels of anger-induced TWA were more likely to experience arrhythmias requiring implantable cardioverter-defibrillator termination," Lampert said.
The study, published in the March issue of the Journal of the American College of Cardiology, said despite factoring for clinical factors that predispose patients to higher anger-induced T-wave alternans -- a measure of the heart's electrical stability -- remained a significant predictor of arrhythmias, which led to a heightened risk of up to 10 times that of other patients.
Ninety-five percent of people who have sudden cardiac arrest die from it -- most within minutes.