Suffering a traumatic event and having underlying cardiac or systemic risks can result in even greater risk to health and risk of mortality. Roughly 8 percent of the population will suffer a traumatic event in their lifetime, and in any given year 8 million adults manifest post-traumatic stress disorder (PTSD).

Those in the military have a high rate of exposure to traumatic events and, as a result, have higher rates of PTSD in any given year. The estimates are 11-20 percent among veterans of Operation Iraqi and Enduring Freedom, 12 percent of veterans of the Gulf War/Desert Storm and the estimates for Vietnam Era veterans are 15 percent, with as many as 30 percent of Vietnam veterans having had PTSD at some point in their lifetime.

As researchers study PTSD more, they are finding a complex interaction between PTSD and medical conditions. A study published this spring by Jack Tsai, Ph.D., from the Veterans Affairs New England Mental Illness, Research, Education, and Clinical Center in West Haven, Connecticut, found a strong association between PTSD and hypercholesterolemia, insulin resistance, angina, heart attack and emphysema among a sample of 1,527 residents of New York City.

Atherosclerotic coronary artery disease was also shown to be associated with PTSD and mortality in 637 veterans with an average age of 61. The authors of the 2011 study¸ Nassar Ahmadi, Ph.D., M.D., from the Greater Los Angeles Veterans Administration Medical Center and his colleagues, concluded that PTSD was associated with the presence and related to the severity of coronary atherosclerosis.

Further, they found in 2015 that this predicted mortality and was unrelated to age, gender or other conventional risk factors. Ahmadi and his colleagues also found that mild traumatic brain injury was associated with the severity of subclinical coronary atherosclerosis and was also predictive of cardiovascular mortality. Earlier this year, the researchers also reported biomarkers of cardiac inflammation as being related to PTSD.

Heart rate variability has been associated with PTSD in a variety of veteran populations. In their study, Joo Eon Park, M.D., and colleagues from the Department of Psychiatry, Keyo Hospital, Uiwang, South Korea, studied Korean veterans. The 68 veterans who had been diagnosed with PTSD and were compared to 73 veterans who did not have PTSD.

The researchers found that those who had PTSD had the lowest variability of heart rate. They concluded that heart rate variability might be an effective measure in assessing autonomic nervous system function in patients with PTSD.

Erik Reinertsen, M.D., Ph.D. candidate from the Department of Biomedical Engineering, Georgia Institute of Technology, used single-channel ECG technology to assess 23 participants who had PTSD and an additional 25 control participants. The researchers developed a classification system using heart rate and heart rate variability measured over 24 hours. They concluded that a classification system had potential to track PTSD severity and thus contribute to better determination of efficacy in treatments of PTSD.

When treating a patient with PTSD, a clinician needs to consider many factors, including those associated with systemic disease.

"The take home-message here for psychiatrists is to consider evaluating the cardiac health of their PTSD patients as well as their psychological health," Ahmadi said.