Low heart rate variability an indicator of mental stress-induced myocardial ischemia
Click Here to Manage Email Alerts
Key takeaways:
- Mental stress-induced autonomic dysfunction may be cause of stress-induced myocardial ischemia in stable CAD.
- The effect was the same regardless of a patient’s age, sex and race.
Low heart rate variability during times of mental stress may be an indicator of stress-induced myocardial ischemia for patients with stable CAD, according to a study published in Circulation: Cardiovascular Imaging.
“The physiological pathways linking stress with a transient myocardial ischemic response have not been delineated. The autonomic nervous system plays an integral role in the body’s response to acute mental stress as a major regulator of the physiological effects of stress on the cardiovascular system,” Jeffery Osei, MD, MPH, a doctoral student in epidemiology at the Rollins School of Public Health at Emory University, and colleagues wrote. “We hypothesized that stress-induced autonomic dysfunction is associated with higher odds of mental stress-induced myocardial ischemia in this high-risk group and that this association differs by sex, age, and race.”
Overall, 735 participants with stable CAD from the MIMS2 and MIPS studies were evaluated to assess the relationship between stress-induced autonomic dysfunction and mental stress-induced myocardial ischemia (mean age, 58 years; 35% women; 44% Black).
Stress-induced autonomic dysfunction was measured via changes in heart rate variability on Holter monitoring during a standardized speech stressor test.
The stressor test involved a 2-minute public speaking exercise in which participants were asked to talk about how they would handle a scenario where a loved one is being mistreated in a nursing home.
Participants underwent three single-photon emission CT myocardial perfusion imaging scans to evaluate myocardial perfusion during rest, mental stress and conventional stress.
Heart rate variability at rest and during stress exercise were categorized into low variability — first quartile — compared with high variability — second to fourth quartiles — with low heart rate variability serving as an indicator of autonomic dysfunction.
In response to the stress exercise, mental stress-induced myocardial ischemia developed in 16% of the cohort.
Compared with high heart rate variability, low variability during stress was associated with twofold higher odds of mental stress-induced myocardial ischemia (OR = 2.1; 95% CI, 1.3-3.3; P = .002).
Heart rate variability during stress was 35% to 38% lower in participants with mental stress-induced myocardial ischemia compared with those without it.
Moreover, the researchers did not observe any significant differences by age, sex or race in the association between low heart rate variability during stress and stress-induced myocardial ischemia.
“The findings in our study are important for both clinical practice and public health. Conventional diagnostic markers for myocardial ischemia, such as ST changes, have poor sensitivity in establishing a diagnosis of mental stress-induced myocardial ischemia. Consequently, they offer little direction for managing mental stress-induced myocardial ischemia. However, the utilization of short-term heart rate variability ... could offer innovative digital health approaches to better detect vulnerability to myocardial ischemia,” the researchers wrote. “Interventions focused on enhancing vagal tone and maintaining sympathovagal balance, such as vagal nerve stimulation or beta-blockers, could be utilized to reduce the occurrence of mental stress-induced myocardial ischemia in high-risk groups and warrant additional study.”
Collapse
Click Here to Manage Email Alerts