Slow breathing improves cardiovascular reactivity to mental stress and health-related quality of life in heart failure patients with reduced ejection fraction

Induced Relaxation Enhances the Cardiorespiratory Dynamics in COVID-19 Survivors

Most COVID-19 survivors report experiencing at least one persistent symptom after recovery, including sympathovagal imbalance. Relaxation techniques based on slow-paced breathing have proven to be beneficial for cardiovascular and respiratory dynamics in healthy subjects and patients with various diseases. Therefore, the present study aimed to explore the cardiorespiratory dynamics by linear and nonlinear analysis of photoplethysmographic and respiratory time series on COVID-19 survivors under a psychophysiological assessment that includes slow-paced breathing. We analyzed photoplethysmographic and respiratory signals of 49 COVID-19 survivors to assess breathing rate variability (BRV), pulse rate variability (PRV), and pulse-respiration quotient (PRQ) during a psychophysiological assessment. Additionally, a comorbidity-based analysis was conducted to evaluate group changes. Our results indicate that all BRV indices significantly differed when performing slow-paced breathing. Nonlinear parameters of PRV were more appropriate for identifying changes in breathing patterns than linear indices. Furthermore, the mean and standard deviation of PRQ exhibited a significant increase while sample and fuzzy entropies decreased during diaphragmatic breathing. Thus, our findings suggest that slow-paced breathing may improve the cardiorespiratory dynamics of COVID-19 survivors in the short term by enhancing cardiorespiratory coupling via increased vagal activity.

Reducing Test Anxiety by Device-Guided Breathing: A Pilot Study

Test anxiety remains a challenge for students and has considerable physiological and psychological impacts. The routine practice of slow, Device-Guided Breathing (DGB) is a major component of behavioral treatments for anxiety conditions. This paper addresses the effectiveness of using DGB as a self-treatment clinical tool for test anxiety reduction. This pilot study sample included 21 healthy men and women, all college students, between the ages of 20 and 30. Participants were randomly assigned to two groups: DGB practice (n = 10) and wait-list control (n = 11). At the beginning and the end of 3-weeks DGB training, participants underwent a stress test, followed by measures of blood pressure and reported anxiety. Anxiety reduction in the DGB group as compared to controls was not statistically significant, but showed a large effect size. Accordingly, the clinical outcomes suggested that daily practice of DGB may lead to reduced anxiety. We assume that such reduction may lead to improved test performance. Our results suggest an alternative treatment for test anxiety that may also be relevant for general anxiety, which is likely to increase due to the ongoing COVID-19 pandemic.

Association between quality of life and mental stress-induced myocardial ischaemia in high-risk patients after coronary revascularization

Objective

We sought to determine the association between mental stress-induced myocardial ischaemia (MSIMI) and quality of life (QoL) in patients with coronary artery disease (CAD) after coronary revascularization.

Methods

This cohort study involved patients with high-risk MSIMI who received coronary revascularization between Dec 2018 and Dec 2019. Patients who screened positive for depression/anxiety were enrolled in this study. Mental stress was induced by the Stroop Colour and Word Test 1 month after coronary revascularization. All participants underwent single photon emission computed tomography (SPECT) scans at rest and under mental stress. MSIMI was defined as the presence of four abnormal SPECT phenomena. QoL was assessed using the Seattle Angina Questionnaire (SAQ) prior to treatment and 1 month after coronary revascularization.

Results

Of the 1845 consecutive patients who received coronary revascularization, 590 (31.9%) had depression/anxiety, and 205 agreed to accept the mental stress test. During the average observation period of 33 days, 105 (51.2%) patients exhibited MSIMI. All SAQ subscales showed significant improvement, except for QoL, in the MSIMI group. The QoL score was lower (− 0.2 ± 32.7 vs. 13.1 ± 29.9, P = 0.005), and the proportion of deterioration in QoL was higher (50.5% vs. 31.9%, P = 0.010) in the MSIMI group than in the non-MSIMI group. Those with a deterioration in QoL had approximately twice the rate of MSIMI than those with an improvement in QoL (unadjusted OR: 2.019, 95% CI 1.122–3.634, P = 0.026; adjusted OR: 1.968, 95% CI 1.083–3.578, P = 0.017).

Conclusion

Among patients with CAD who received coronary revascularization and had depression/anxiety, deterioration in QoL increased the likelihood of MSIMI. Hence, our results indicate that deterioration in QoL is a predictor of MSIMI.

Trail Registration ChiCTR2200055792, retrospectively registered, 2022.1.20, www.medresman.org.cn

The Importance of Respiratory Rate Monitoring: From Healthcare to Sport and Exercise

Respiratory rate is a fundamental vital sign that is sensitive to different pathological conditions (e.g., adverse cardiac events, pneumonia, and clinical deterioration) and stressors, including emotional stress, cognitive load, heat, cold, physical effort, and exercise-induced fatigue. The sensitivity of respiratory rate to these conditions is superior compared to that of most of the other vital signs, and the abundance of suitable technological solutions measuring respiratory rate has important implications for healthcare, occupational settings, and sport. However, respiratory rate is still too often not routinely monitored in these fields of use. This review presents a multidisciplinary approach to respiratory monitoring, with the aim to improve the development and efficacy of respiratory monitoring services. We have identified thirteen monitoring goals where the use of the respiratory rate is invaluable, and for each of them we have described suitable sensors and techniques to monitor respiratory rate in specific measurement scenarios. We have also provided a physiological rationale corroborating the importance of respiratory rate monitoring and an original multidisciplinary framework for the development of respiratory monitoring services. This review is expected to advance the field of respiratory monitoring and favor synergies between different disciplines to accomplish this goal.

Tai Chi Improves Coronary Heart Disease Risk by Inactivating MAPK/ERK Pathway through Serum miR-126

Background

Tai Chi is effective in preventing heart disease (CHD) risk, but the molecular mechanism remains unclear. Mitogen-activated protein kinase (MAPK) signaling plays a critical role in the pathogenesis of CHD and can be activated by miR-126. Tai Chi may exert its protective function through the miR-126-modulated MAPK pathway.

Methods

The CHD patients after PCI were randomized into the CG group (CG) (n = 19, normal care) and Tai Chi group (TG) (Tai Chi intervention, n = 17). Epicardial adipose tissue volume (EATV) (one main adverse cardiovascular event of CHD), HR (heart rate), QoL (quality of life) scores, and balance performance were measured in the two groups. The body fat content, abdominal subcutaneous fat, and visceral fat were measured to reflect the improvement of adipose tissue dysfunction. The levels of miR-126 and MAPK-associated molecules were measured in peripheral blood leukocytes. Meanwhile, the effects of miR-126 silence and mimic on MAPK-associated molecules were also explored in cardiac cell H9C2.

Results

After the 3-month intervention, Tai Chi reduced EATV and HR and increased QoL scores and balance performance, respectively (P < 0.05). The fat percentage, body fat mass, and BMI were also significantly reduced after Tai Chi intervention (P < 0.05). The levels of miR-126, MAPK, JNK, and ERK in the TG group were lower than those in the CG group (P < 0.05). The miR-126 levels had a strong relationship with the values of EATV, HR, and QoL scores (P < 0.05). miR-126 silence or mimic inactivated or activated MAPK-associated molecules in the cardiac cell lines.

Conclusions

Tai Chi improved CHD risk by inactivating the MAPK/ERK pathway via serum miR-126.

Acute effects of resonance frequency breathing on cardiovascular regulation

Acute slow breathing may have beneficial effects on cardiovascular regulation by affecting hemodynamics and the autonomic nervous system. Whether breathing at the resonance frequency (RF), a breathing rate that maximizes heart rate oscillations, induces differential effects to that of slow breathing is unknown. We compared the acute effects of breathing at either RF and RF + 1 breaths per minute on muscle sympathetic nervous activity (MSNA) and baroreflex function. Ten healthy men underwent MSNA, blood pressure (BP), and heart rate (HR) recordings while breathing for 10 min at their spontaneous breathing (SB) rate followed by 10 min at both RF and RF + 1 randomly assigned and separated by a 10-min recovery. Breathing at either RF or RF + 1 induced similar changes in HR and HR variability, with increased low frequency and decreased high frequency oscillations (p < .001 for both). Both respiration rates decreased MSNA (-5.6 and -7.3 bursts per min for RF and RF + 1 p < .05), with the sympathetic bursts occurring more often during mid-inspiration to early expiration (+57% and + 80%) and longer periods of silence between bursts were seen (p < .05 for RF + 1). Systolic BP was decreased only during RF (-4.6 mmHg, p < .05) but the decrease did not differ to that seen during RF + 1 (-3.1 mmHg). The sympathetic baroreflex function remained unchanged at either breathing rates. The slope of the cardiac baroreflex function was unaltered but the cardiac baroreflex efficiency was improved during both RF and RF + 1. Acute breathing at either RF or RF + 1 has similar hemodynamic and sympatho-inhibitory effects in healthy men.

Tachycardia: The hidden cardiovascular risk factor in uncomplicated arterial hypertension

Early detection and management of elevated blood pressure is crucial in reducing the burden of cardiovascular disease (CVD). The importance of an absolute risk assessment and patient risk stratification has been highlighted in the European hypertension guidelines since 2003. Amongst numerous risk factors influencing patient prognosis, elevated heart rate (HR) has been indicated as important predictor of future risk of hypertension, coronary heart disease, sudden cardiac death, heart failure, CVD, stroke, total cancer and mortality. Given that resting HR can be easily determined in clinical practice and modified by lifestyle changes as well as beta-blocker therapy, it seems reasonable that lowering resting HR should be a potential target to reduce disease burden and premature mortality. However, there is a lack of outcome studies of HR lowering in tachycardia-related hypertension. This review outlines the underlying mechanisms of early course hypertension pathophysiology with the critical role of the sympathetic nervous system activation, the prognostic significance of fast HR and the mechanistic rationale for the use of non-pharmacological approaches and/or highly long-acting cardioselective beta-blockers with some consideration given to betaxolol properties.