Fear of terrorism increases basal (resting) heart rate, risk of death
“We wanted to test whether fear of terrorism can predict an increase in pulse rate and increased risk of death,” explains Prof. Soreq.
By combining the medical exam data with the questionnaire responses, the researchers found that basal heart rate was affected by physiological characteristics, such as level of physical fitness and inflammation index reflecting the activity of the immune system.
In contrast, an ongoing increase in heart rate was also influenced by psychological characteristics such as fear of terrorism. Through a statistical analysis of 325 different parameters, the researchers found that fear of terror was a major contributor to annual increases in resting heart rate, with 4.1 percent of study participants suffering from an elevated fear of terror that predicted an increase in their resting heart rates.
While a heartbeat of 60 beat per minute is normal, an increase of up to 70-80 beats per minute was observed in subjects who exhibited an increased fear of terrorism. In other words, for people with an elevated fear of terror, the heart beats faster and the associated risk of heart disease is higher.
Elevated resting heart rate is a predictor of death from cardiovascular disease and death across all causes. As people age, the resting heart rate typically decreases from year to year, and people whose heart rate actually increases annually are more susceptible than others to heart attacks and strokes.
The researchers also examined how the brain alerts the body to the expectation of danger. They administered a blood test to examine the function of acetylcholine, a neurotransmitter involved in responses to stress and which acts as a brake to the inflammatory response.
The results showed that the fear of terror leads to a decline in the function of acetylcholine, and thus reduces the body’s ability to defend itself from a heart attack, leading to a greater chance of dying.
“We found that fear of terrorism and existential anxiety may disrupt the control processes using acetylcholine, causing a chronic accelerated heart rate. Together with inflammation, these changes are associated with increased risk of heart attack and stroke,” Prof. Soreq said.
The researchers also found that levels of C-reactive protein, a biomarker for inflammation, were elevated in those volunteers who fear terror and show escalated pulse. This finding further suggests that long-term exposure to terror threats may combine with inflammation to elevate resting heart rates and thus increase the risk of mortality.
The researchers suggest that since information on heart rate and its time-related changes is easy to follow, the findings may be useful in identifying asymptomatic people who could benefit from primary prevention measures designed to limit increases in cardiovascular mortality risk. These could include vagal stimulation, anti-inflammatory or anti-cholinesterase medications or physical activity.
— Read more in Shani Shenhar-Tsarfaty et al., “Fear and C-reactive protein co-synergize annual pulse increases in healthy adults,” Proceedings of the National Academy of Sciences (22 December 2014) (doi: 10.1073/pnas.1418264112)
