November 4 (HealthDay News) -- Post-traumatic stress disorder (PTSD) linked to a heart attack can raise the long term risk of death for people with implanted cardiac defibrillators, a new study suggests.

Surviving a heart attack or cardiac arrest can cause significant distress. As a result, many patients later develop PTSD, which includes intense anxiety, flashbacks and "hyperarousal," according to background information in the article.

The German study, published in the November issue of Archives of General Psychiatry, found that almost 70 percent of the 211 recipients of the heart-shocking devices experienced some PTSD symptoms. About 31 percent of the recipients died within five years of the attack, and those with PTSD were about 2.4 times more likely to be among the deceased.

"Our findings provide direct evidence for an independent influence of PTSD symptoms on fatal outcome in these patients," wrote the authors of the study, led by Dr. Karl-Heinz Ladwig of Technische Universitaet Muenchen, Munich.

While patients with PTSD in the study reported more cardiac symptoms (such as chest pain) than those without the disorder, the clinical experiences in such patients -- for example, the frequency at which their defibrillator administers shocks -- were similar between the two groups.

"Therefore, the perceived severity rather than the objective severity of a cardiac condition as determined by cardiac criteria may be associated with PTSD," the authors wrote.

They called for further studies to determine whether behavioral and biological factors affect the death rates in these patients, but in the meantime, they called for screening for PTSD in patients with implantable cardiac defibrillators, as it is "likely to be clinically beneficial, and treatment in selected patients should be attempted."

SOURCE: JAMA Archives journals, news release, Nov. 3, 2008