Screening of Pathophysiological Mechanisms and Psychological and Occupational Factors, Determining Risk of Cardiovascular Diseases in High-Risk Professions

Cardiovascular diseases (CVD) are among the most significant and common chronic non-communicable diseases in Bulgaria. Screening, identification and registration of pathophysiological mechanisms and psychological and occupational factors related to CVD should be implemented in the diagnostic work-up. Job analysis contributes to the implementation of screening and identification of the most significant psychological and professional factors related to the work activity.Aim: The aim of our study is to examine the pathophysiological mechanisms of autonomic cardiovascular control and psychological and occupational factors determining the risk of CVD.Materials and methods: The following groups of individuals were examined: 83 physicians, 54 nurses, 23 employees and 40 militaries. The autonomic cardiovascular control was studied through the time-and frequency-domain based measures of the Analysis of Heart Rate Variability (HRV).Results: The results of the ANOVA test showed that there was a statistically significant difference in the time-domain and frequency-domain based HRV measures between the compared groups: X [F (4; 225) = 4.455, p = 0.001]; SDNN [F (4; 225) = 3.876, p = 0.005]; SDNN5 [F (4; 225) = 3.083, p = 0.01]; pNN50 [F (4; 225) = 8.303, p < 0.001]; rMSSD [F (4; 225) = 8.711, p < 0.001]; SDSD [F (4; 225) = 8.323, p < 0.001; VLF [F (4; 225) = 1.204, p = 0.31]; LF [F (4; 225) = 3.874, p = 0.005]; HF [F (4; 225) = 7.790, p < 0.001] and LF/HF [F (4; 225) = 8.601, p < 0.001]. The results of our study revealed that occupational stress and cognitive workload in physicians, nurses, and employees induced a process of reciprocally combined inhibition of the parasympathetic branch of the autonomic nervous system (ANS) (SDNN, SDNN5, pNN50, rMSSD, and HF) and activation of the sympathetic branch of ANS (LF), while in military personnel they cause a process of co-activation of the parasympathetic and sympathetic branches of the ANS (rMSSD, SDNN, SDNN5, pNN50 and LF/HF).Conclusion: Stress-induced dysfunctional autonomic cardiovascular regulation, patho-physiological control mechanisms, psychological and occupational factors determine the risk of CVD. Their identification could contribute to the diagnostics and prevention of CVD.

Baroreceptor denervation reduces inflammatory status and worsens cardiovascular collapse during systemic inflammation

ABSTRACTBeyond the regulation of cardiovascular function, baroreceptor afferents play polymodal roles. We hypothesized that baroreceptor denervation affects lipopolysaccharide (LPS)-induced systemic inflammation (SI) and hemodynamic collapse in conscious rats, and that these parameters are interconnected. We combine: a) hemodynamic and thermoregulatory recordings after LPS administration at a septic-like dose b) analysis of the cardiovascular complexity, c) evaluation of vascular function in mesenteric resistance vessels, and d) measurements of inflammatory cytokines (plasma and spleen). LPS-induced drop in blood pressure was higher in sino-aortic denervated (SAD) rats. LPS-induced hemodynamic collapse was associated with SAD-dependent autonomic disbalance. LPS-induced vascular dysfunction was not affected by SAD. Surprisingly, SAD blunted LPS-induced surges of plasma and spleen cytokines. These data indicate that sino-aortic afferents are key to alleviate LPS-induced cardiovascular collapse, affecting the autonomic cardiovascular control, without affecting resistance blood vessels. Moreover, baroreflex modulation of the LPS-induced SI and hemodynamic collapse seem not to be interconnected.

Relationship between Ischemic Stroke and Pulse Rate Variability as a Surrogate of Heart Rate Variability

Autonomic reflex ascertains cardiovascular homeostasis during standing. Impaired autonomic reflex could lead to dizziness and falls while standing; this is prevalent in stroke survivors. Pulse rate variability (PRV) has been utilized in the literature in lieu of heart rate variability (HRV) for ambulatory and portable monitoring of autonomic reflex predominantly in young, healthy individuals. Here, we compared the PRV with gold standard HRV for monitoring autonomic reflex in ischemic stroke survivors. Continuous blood pressure and electrocardiography were acquired from ischemic stroke survivors (64 ± 1 years) and age-matched controls (65 ± 2 years) during a 10-minute sit-to-stand test. Beat-by-beat heart period (represented by RR and peak-to-peak (PP) intervals), systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse arrival time (PAT), an indicator of arterial stiffness, were derived. Time and frequency domain HRV (from RR intervals) and PRV (from PP intervals) metrics were extracted. PAT was lower (248 ± 7 ms vs. 270 ± 8 ms, p < 0.05) suggesting higher arterial stiffness in stroke survivors compared to controls during standing. Further, compared to controls, the agreement between HRV and PRV was impaired in stroke survivors while standing. The study outcomes suggest that caution should be exercised when considering PRV as a surrogate of HRV for monitoring autonomic cardiovascular control while standing in stroke survivors.