Cardiac Autonomic Nervous System Activity and Cardiac Function in Children After Coarctation Repair

Cardiorespiratory fitness, regular physical activity, and autonomic nervous system reactivity to laboratory and daily life stress

The cross-stressor adaptation hypothesis-which posits that adjustment to physical stress as a result of regular physical activity and its effects on fitness crosses over to psychological stress reactivity-has been around for over four decades. However, the literature has been plagued by heterogeneities preventing definitive conclusions. We address these heterogeneity issues in a combined laboratory and daily life study of 116 young adults (M = 22.48 SD = 3.56, 57.76% female). The exposure, i.e., the potential driver of adaptation, was defined in three ways. First, a submaximal test was performed to obtain aerobic fitness measured as the VO₂ max (kg/ml/min). Second, leisure time exercise behavior, and third, overall moderate-to-vigorous physical activity (MVPA), were obtained from a structured interview. Outcomes were autonomic nervous system (ANS) reactivity and affective responsiveness to stressors. ANS activity was measured continuously and expressed as inter-beat-interval (IBI), pre-ejection-period (PEP), respiratory sinus arrythmia (RSA), and non-specific Skin Conductance Responses (ns.SCR). Negative and positive affect were recorded after each experimental condition in the laboratory and hourly in daily life with a nine-item digital questionnaire. Linear regressions were performed between the three exposure measures as predictors and the various laboratory and daily life stress measurements as outcomes. Our results support the resting heart rate reducing effect of aerobic fitness and total MVPA in both the laboratory and daily life. We did not find evidence for the cross-stressor adaptation hypothesis, irrespective of ANS or affective outcome measure or whether the exposure was defined as exercise/MVPA or aerobic fitness.

Decreased cardiac output: an integrative review

OBJECTIVE

to identify, in the scientific literature, the defining characteristics and contributing factors (related factors, associated conditions and populations at risk) for nursing diagnosis decreased cardiac output.

METHOD

an integrative literature review, conducted between September and October 2020, with an update in March 2022, in the MEDLINE via PubMed, LILACS, SciELO, CINAHL and EMBASE databases. Using acronym PEO, studies published in the last 10 years in Portuguese, English and Spanish were included. A descriptive analysis was carried out to present the elements mapped in the literature.

RESULTS

analysis of 31 articles identified different elements, highlighting 4 new related factors: hyperglycemic stress, prone position, left lateral position, sleep deprivation. Individuals with a history of cardiovascular disease and males were identified as possible populations at risk.

FINAL CONSIDERATIONS

the elements for decreased cardiac output, identified in the literature, add evidence that justifies the permanence of this diagnosis in the NANDA-I classification.

Débito cardíaco diminuído: revisão integrativa

RESUMO Objetivo: identificar, na literatura científica, as características definidoras e fatores contribuintes (fatores relacionados, condições associadas e populações em risco) para o diagnóstico de enfermagem débito cardíaco diminuído. Método: revisão integrativa da literatura, conduzida entre setembro e outubro de 2020, com atualização em março de 2022, nas bases de dados MEDLINE via PubMed, LILACS, SciELO, CINAHL e EMBASE. Com uso do acrônimo PEO, foram incluídos estudos publicados nos últimos 10 anos em português, inglês e espanhol. Realizouse análise descritiva para apresentar os elementos mapeados na literatura. Resultados: análise de 31 artigos identificou diferentes elementos, com destaque para 4 novos fatores relacionados: estresse hiperglicêmico, posição prona, posição lateral esquerda, privação do sono. Indivíduos com história de doença cardiovascular e do sexo masculino foram apontados como possíveis populações em risco. Considerações finais: os elementos para débito cardíaco diminuído, identificados na literatura, agregam evidências que justificam a permanência desse diagnóstico na classificação da NANDA-I.

The short Sing-a-Song Stress Test: A practical and valid test of autonomic responses induced by social-evaluative stress

The Sing-a-Song Stress Test (SSST) was recently developed as an alternative to the Trier Social Stress Test (TSST) to investigate autonomic nervous system responses to social-evaluative stress. In the SSST, participants are suddenly cued to sing a song in the presence of confederates. However, the SSST is still quite long (~15 min) and the requirement for confederates makes it labor-intensive. The current study tested whether a shorter (~6.5 min), single-experimenter, version of the SSST can still reliably elicit subjective and physiological stress reactivity. Our sample consisted of 87 healthy young adult participants (age range: 18-35 years). During the short SSST and a speeded reaction time task, in which aversive loud tones were to be avoided (TA), we measured heart period (HP), sympathetic nervous system (SNS) activity using pre-ejection-period (PEP), skin conductance level (SCL), and non-specific skin conductance responses (ns.SCR), and parasympathetic nervous system (PNS) activity using respiratory-sinus-arrhythmia (RSA) and the root-mean-square of successive differences (RMSSD). The short SSST induced significant decreases in positive affect and increases in negative affect. MANOVAs on the clusters of SNS and PNS variables showed that the short SSST elicited significant HP (-118.46 ms), PEP (-7.76 ms), SCL (+4.85 μS), ns.SCR (+8.42 peaks/min) and RMSSD (-14.67) reactivity. Affective, SNS, and PNS reactivity to the new SSST social-evaluative stress task were of comparable magnitude to that evoked by the TA mental stressor. We conclude that the short SSST is a valid and cost-effective task for large scaled studies to induce social-evaluative stress to a sufficient degree to evoke measurable changes in PNS and SNS activity and affective state.

The effects of age at correction of aortic coarctation and recurrent obstruction on adolescent patients: MRI evaluation of wall shear stress and pulse wave velocity

Background

Coarctation patients before curative reconstruction are exposed to abnormal flow patterns which potentially could cause wall deterioration. This study evaluated the effect of age at correction on the pulse wave velocity (PWV) and peak wall shear stress (WSS) in adolescent patients with corrected coarctation. Effects of valve morphology and presence of reobstruction were also evaluated.

Methods

Twenty-one patients aged 13.7 ± 2.6 years (mean ± standard deviation) were included (bicuspid aortic valve, n = 14; reobstruction, n = 9). Mean age at correction was 1.0 ± 1.8 years. PWV was determined from two high-temporal through-plane phase-contrast magnetic resonance imaging (MRI) acquisitions, for two segments: ascending aorta plus aortic arch and descending aorta. WSS was determined from four-dimensional flow MRI. Peak WSS over five systolic phases was determined for ascending aorta, aortic arch, and descending aorta.

Results

Patients with tricuspid aortic valve showed a significant correlation between the age at correction and descending aorta PWV (r_s = 0.80, p = 0.010). Significant differences were found between patients without and with reobstruction for peak WSS in the aortic arch (3.9 ± 1.3 Pa versus 6.5 ± 2.2 Pa, respectively; p = 0.003) and descending aorta (5.0 ± 1.3 Pa versus 6.7 ± 1.1 Pa, respectively; p = 0.005).

Conclusions

A prolonged period of abnormal haemodynamic exposure may result in increased aortic wall stiffening. The increased peak WSS as results of a reobstruction possibly promotes different disease progression, which endorse longitudinal follow-up examination of corrected coarctation patients.

Pharmacological Modulation of Vagal Nerve Activity in Cardiovascular Diseases

Cardiovascular diseases are life-threatening illnesses with high morbidity and mortality. Suppressed vagal (parasympathetic) activity and increased sympathetic activity are involved in these diseases. Currently, pharmacological interventions primarily aim to inhibit over-excitation of sympathetic nerves, while vagal modulation has been largely neglected. Many studies have demonstrated that increased vagal activity reduces cardiovascular risk factors in both animal models and human patients. Therefore, the improvement of vagal activity may be an alternate approach for the treatment of cardiovascular diseases. However, drugs used for vagus nerve activation in cardiovascular diseases are limited in the clinic. In this review, we provide an overview of the potential drug targets for modulating vagal nerve activation, including muscarinic, and β-adrenergic receptors. In addition, vagomimetic drugs (such as choline, acetylcholine, and pyridostigmine) and the mechanism underlying their cardiovascular protective effects are also discussed.

Automated Cardiac Valve Tracking for Flow Quantification with Four-dimensional Flow MRI

Purpose To compare four-dimensional flow MRI with automated valve tracking to manual valve tracking in patients with acquired or congenital heart disease and healthy volunteers. Materials and Methods In this retrospective study, data were collected from 114 patients and 46 volunteers who underwent four-dimensional flow MRI at 1.5 T or 3.0 T from 2006 through 2017. Among the 114 patients, 33 had acquired and 81 had congenital heart disease (median age, 17 years; interquartile range [IQR], 13-49 years), 51 (45%) were women, and 63 (55%) were men. Among the 46 volunteers (median age, 28 years; IQR, 22-36 years), there were 19 (41%) women and 27 (59%) men. Two orthogonal cine views of each valve were used for valve tracking. Wilcoxon signed-rank test was used to compare analysis times, net forward volumes (NFVs), and regurgitant fractions. Intra- and interobserver variability was tested by using intraclass correlation coefficients (ICCs). Results Analysis time was shorter for automated versus manual tracking (all patients, 14 minutes [IQR, 12-15 minutes] vs 25 minutes [IQR, 20-25 minutes]; P < .001). Although overall differences in NFV and regurgitant fraction were comparable between both methods, NFV variation over four valves was smaller for automated versus manual tracking (all patients, 4.9% [IQR, 3.3%-6.7%] vs 9.8% [IQR, 5.1%-14.7%], respectively; P < .001). Regurgitation severity was discordant for seven pulmonary valves, 22 mitral valves, and 21 tricuspid valves. Intra- and interobserver agreement for automated tracking was excellent for NFV assessment (intra- and interobserver, ICC ≥ 0.99) and strong to excellent for regurgitant fraction assessment (intraobserver, ICC ≥ 0.94; interobserver, ICC ≥ 0.89). Conclusion Automated valve tracking reduces analysis time and improves reliability of valvular flow quantification with four-dimensional flow MRI in patients with acquired or congenital heart disease and in healthy volunteers. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by François in this issue.