Severity of Myocardial Ischemia Is Related to Career Length Rather Than Age Among Professional Firefighters

Background: Ischemic heart disease (IHD) is the major cause of duty-related fatalities in the fire service. Age and career length are not only important risk factors associated with IHD, but are also highly correlated. The aim of this secondary analyses was to assess the relationship between age, career length, and IHD, based on ischemic severity, to identify whether age or career length had a stronger relationship to IHD. Methods: This was a secondary, correlational analysis of on-duty firefighters without known cardiovascular or respiratory disease who underwent exercise treadmill testing with 12-lead electrocardiography. Ischemia was defined based on current guidelines. Maximum ST-segment depression was measured to determine IHD ischemic severity. Age, years of employment, demographics, weight, blood pressure were recorded. Multiple correlations were computed between age, career length, and IHD. Findings: Twenty-two firefighters were included (96% male, 82% White, 82% overweight or obese, 77% hypertensive). The partial correlation between maximum ST-segment depression and age controlled for career length was not significant ( r = –.392, p = .079). The partial correlation between maximum ST-segment depression and career length controlled for age was statistically significant ( r = .466, p = .033). Conclusion/Application to Practice: Career length, not age, moderately correlates with IHD ischemic severity among firefighters. Career length is a proxy measure of occupational exposures which contributes to IHD. When assessing IHD risk in firefighters, health practitioners should consider incorporating the occupational exposure history (i.e., career length) in addition to age when providing risk reduction services.

From Prevention to Disease Perturbations: A Multi-Omic Assessment of Exercise and Myocardial Infarctions

While a molecular assessment of the perturbations and injury arising from diseases is essential in their diagnosis and treatment, understanding changes due to preventative strategies is also imperative. Currently, complex diseases such as cardiovascular disease (CVD), the leading cause of death worldwide, suffer from a limited understanding of how the molecular mechanisms taking place following preventive measures (e.g., exercise) differ from changes occurring due to the injuries caused from the disease (e.g., myocardial infarction (MI)). Therefore, this manuscript assesses lipidomic changes before and one hour after exercise treadmill testing (ETT) and before and one hour after a planned myocardial infarction (PMI) in two separate patient cohorts. Strikingly, unique lipidomic perturbations were observed for these events, as could be expected from their vastly different stresses on the body. The lipidomic results were then combined with previously published metabolomic characterizations of the same patients. This integration provides complementary insights into the exercise and PMI events, thereby giving a more holistic understanding of the molecular changes associated with each.

Handrail support interference in cardiac autonomic modulation adjustments in young adults during maximal exercise testing

The aim of this study was to investigate whether the use of handrail support during maximal exercise treadmill testing (ETT) would interfere in cardiac autonomic modulation kinetics when compared to not using handrail support. The hypothesis of overestimation in cardiac autonomic dynamics when the ETT is performed using handrail was tested. Thirty-five undergraduates (21.08 ± 2.98 years old) of both sexes, volunteered to undertake two ETT under the Ellestad protocol, in non-consecutive days. The first test (T1) was performed with handrail support and, after 7 days, the second test was performed (T2) without the support. Autonomic function was measured by heart rate variability (HRV) during both tests and resting. Estimated value of peak oxygen uptake (VO2) was 22.4% (p < 0.0001) higher in T1 when compared to T2. Overall, parasympathetic pathway was deactivated earlier in T2 than in T1, with NNxx measures variating in T1 from 10.74 ± 14.59 (ms) and in T2 from 3.48 ± 3.79 (ms). In stage two, mean values of HF in T2 corresponded to 32% of values in T1. Stage three presented a difference of 60% (p < 0.014) in LF between means reached in T1 and T2. Lastly, the association of LF and VO2 persisted longer in T1 stages than in T2 and was verified in early stages (S2 and S3) of both ETTs. Our findings suggest that parasympathetic influences on HR were slightly prolonged during ETT when subjects hold onto the treadmill.

Peak Responses during Exercise Treadmill Testing using Individualized Ramp Protocol and Modified Bruce Protocol in Elderly Patients

Background: Exercise capacity is well known to be an important prognostic factor in patients with cardiovascular disease and among healthy persons. &nbsp; Aim: To determine if there are any differences between the peak exercise response during exercise treadmill testing with the individualized ramp protocol and the modified Bruce protocol in elderly patients. &nbsp; Materials and methods: The study included 40 patients (both male and female), aged 70 years and older, who had not had a baseline history of the confirmed coronary artery disease or heart failure diagnoses. All patients underwent exercise treadmill testing using modified Bruce protocol and individualized ramp protocol for 2 consecutive days. Peak heart rate, peak systolic and diastolic blood pressure, peak pressure-rate double product, exercise duration, and peak metabolic equivalents were recorded in both tests. Perceived level of exertion was evaluated using the Borg 10-point scale. &nbsp; Results: The average duration of exercise was longer for the ramp protocol than for the modified Bruce protocol. When the modified Bruce protocol was used, patients achieved a lower workload than they did in using the ramp protocol. The rating of perceived exertion using the revised Borg scale (0 to 10) was 5.6&plusmn;1.4 for the ramp protocol and 8.7&plusmn;1.4 for the modified Bruce protocol, which indicates that the patients found the ramp protocol easier. &nbsp; Conclusion: In elderly patients the individualized ramp treadmill protocol allows to achieve the optimal test duration with higher degrees of workload and greater patient comfort during the test more often than does the modified Bruce protocol.