Evening but not morning aerobic training improves sympathetic activity and baroreflex sensitivity in elderly patients with treated hypertension.

The blood pressure-lowering effect of aerobic training is preceded by improving cardiovascular autonomic control. We previously demonstrated that aerobic training conducted in the evening (ET) induces a greater decrease in blood pressure than morning training (MT). To study whether the greater blood pressure decrease after ET occurs through better cardiovascular autonomic regulation, this study aimed to compare MT versus ET on muscle sympathetic nerve activity (MSNA) and baroreflex sensitivity (BRS) in treated patients with hypertension. Elderly patients treated for hypertension were randomly allocated into MT (n = 12, 07.00-10.00 h) or ET (n = 11, 17.00-20.00 h) groups. Both groups trained for 10 weeks, 3 times/week, cycling for 45 min at moderate intensity. Beat-to-beat blood pressure (finger photoplethysmography), heart rate (electrocardiography) and MSNA (microneurography) were assessed at the initial and final phases of the study at baseline and during sequential bolus infusions of sodium nitroprusside and phenylephrine (modified-Oxford technique) to evaluate cardiac and sympathetic BRS. Mean blood pressure decreased significantly after ET but not after MT (-9 ± 11 vs. -1 ± 8 mmHg, P = 0.042). MSNA decreased significantly only after ET with no change after MT (-12 ± 5 vs. -3 ± 7 bursts/100 heart beats, P = 0.013). Sympathetic BRS improved after ET but not after MT (-0.8 ± 0.7 vs. 0.0 ± 0.8 bursts/100 heart beats/mmHg, P = 0.052). Cardiac BRS improved similarly in both groups (ET: +1.7 ± 1.8 vs. MT: +1.4 ± 1.9 ms/mmHg, Pphase  ≤ 0.001). In elderly patients treated for hypertension, only ET decreased mean blood pressure and MSNA and improved sympathetic BRS. These findings revealed that the sympathetic nervous system has a key role in ET's superiority to MT in blood pressure-lowering effect. KEY POINTS: Reducing muscle nerve sympathetic activity and increasing sympathetic baroreflex sensitivity plays a key role in promoting the greater blood pressure reduction observed with evening training. These findings indicated that simply changing the timing of exercise training may offer additional benefits beyond antihypertensive medications, such as protection against sympathetic overdrive and loss of baroreflex sensitivity, independent markers of mortality. Our new findings also suggest new avenues of investigation, such as the possibility that evening aerobic training may be beneficial in other clinical conditions with sympathetic overdrive, such as congestive heart failure and hypertrophic cardiomyopathy.

Sympathetic Neural Overdrive, Aortic Stiffening, Endothelial Dysfunction, and Impaired Exercise Capacity in Severe COVID-19 Survivors: A Mid-Term Study of Cardiovascular Sequelae.

BACKGROUND: COVID-19 has become a dramatic health problem during this century. In addition to high mortality rate, COVID-19 survivors are at increased risk for cardiovascular diseases 1-year after infection. Explanations for these manifestations are still unclear but can involve a constellation of biological alterations. We hypothesized that COVID-19 survivors compared with controls exhibit sympathetic overdrive, vascular dysfunction, cardiac morpho-functional changes, impaired exercise capacity, and increased oxidative stress. METHODS: Nineteen severe COVID-19 survivors and 19 well-matched controls completed the study. Muscle sympathetic nerve activity (microneurography), brachial artery flow-mediated dilation and blood flow (Doppler-Ultrasound), carotid-femoral pulse wave velocity (Complior), cardiac morpho-functional parameters (echocardiography), peak oxygen uptake (cardiopulmonary exercise testing), and oxidative stress were measured ~3 months after hospital discharge. Complementary experiments were conducted on human umbilical vein endothelial cells cultured with plasma samples from subjects. RESULTS: Muscle sympathetic nerve activity and carotid-femoral pulse wave velocity were greater and brachial artery flow-mediated dilation, brachial artery blood flow, E/e' ratio, and peak oxygen uptake were lower in COVID-19 survivors than in controls. COVID-19 survivors had lower circulating antioxidant markers compared with controls, but there were no differences in plasma-treated human umbilical vein endothelial cells nitric oxide production and reactive oxygen species bioactivity. Diminished peak oxygen uptake was associated with sympathetic overdrive, vascular dysfunction, and reduced diastolic function in COVID-19 survivors. CONCLUSIONS: Our study revealed that COVID-19 survivors have sympathetic overactivation, vascular dysfunction, cardiac morpho-functional changes, and reduced exercise capacity. These findings indicate the need for further investigation to determine whether these manifestations are persistent longer-term and their impact on the cardiovascular health of COVID-19 survivors.

Reabilitação cardiovascular com ênfase no exercício físico para pacientes com doença arterial coronariana: visão crítica do cenário atual / Cardiovascular rehabilitation with an emphasis on physical exercise for patients with coronary artery disease: a critical review of the current scenario

A doença arterial coronariana (DAC) é umas das doenças cardiovasculares que mais mata no Brasil e no mundo. É uma doença multifatorial, associada a fatores de risco modificáveis. Além dos tratamentos convencionais, é recomendado que pacientes com DAC também incluam modificações no estilo de vida e programas de reabilitação cardiovascular com ênfase no exercício físico (RCEE) em seu tratamento. Sabidamente, o exercício físico regular somado às mudanças no estilo de vida contribui para a diminuição do avanço da doença aterosclerótica e da mortalidade dos pacientes com DAC. Além disso, o exercício físico tem impacto benéfico na capacidade funcional e qualidade de vida. Um programa de RCEE é uma estratégia eficaz, segura e com excelente razão de custo-benefício para o tratamento da DAC. Contudo, mesmo sendo uma terapia recomendada pelos principais órgãos de saúde, no Brasil as políticas públicas de saúde são extremamente escassas e a quantidade de centros especializados que oferecem a RCEE também é baixa. Problemas de adesão, participação e motivação são evidentes quando os programas são avaliados. Esta revisão mostra os principais estudos que, ao longo das últimas décadas, deram base para as recomendações da RCEE e faz uma análise crítica do cenário atual, deixando claro que novas estratégias de atuação e monitoramento devem ser exploradas e incentivadas para que os programas de RCEE sejam incluídos efetivamente no tratamento dos pacientes com DAC

Coronary artery disease (CAD) is one of the most lethal cardiovascular diseases both in Brazil and worldwide. It is a multifactorial disease associated with modifiable risk factors. In addition to conventional treatments, it is recommended that patients with CAD also include lifestyle changes and exercise-based cardiovascular rehabilitation (CR) programs in their treatment. It is well known that regular physical exercise combined with lifestyle changes contributes to a reduction in the progression of atherosclerosis and in mortality in patients with CAD. Moreover, physical exercise has a beneficial impact on functional capacity and quality of life. A CR program is an effective, safe strategy for the treatment of CAD with an excellent cost-benefit ratio. However, even though it is a therapy recommended by the main health agencies, public health policies in Brazil are extremely scarce and the number of specialized centers that offer CR is low. Problems of adherence, participation, and motivation are evident when these programs are evaluated. This review looks at the main studies that have been the basis for the recommendations of CR over last decades and critically analyzes the current scenario, making it clear that new strategies for action and monitoring should be explored and encouraged such that CR programs will be included effectively in the treatment of patients with CAD

Exercise Training Improves Heart Rate Recovery after Exercise in Hypertension

Abstract Aim: This study tested the hypothesis that: 1- the exercise training would improve the heart rate recovery (HRR) decline after maximal exercise test in hypertensive patients and; 2- the exercise training would normalize HRR decline when compared to normotensive individuals. Methods: Sixteen hypertensive patients were consecutively allocated into two groups: Exercise-trained (n = 9, 47±2 years) and untrained (n = 7, 42±3 years). An exercise-trained normotensive group (n = 11, 41±2 years) was also studied. Heart rate was evaluated by electrocardiogram. The autonomic function was evaluated based on heart rate changes on the first and the second min of recovery after the maximal exercise test. Exercise training consisted of three 60-minute exercise sessions/week for 4 months. Results: In hypertensive patients, exercise training significantly increased the HRR decline in the first (-19±2 vs. -34±3 bpm, P = 0.001) and second (-33±3 vs. -49±2 bpm, P = 0.006) minutes after the maximal exercise test. In addition, after exercise training, the initial differences in the HRR decline after exercise between hypertensive patients and normotensive individuals were no longer observed (first minute: -34±3 vs. -29±3 bpm, P = 0.52, and second minute: -49±2 vs. -47±4 bpm, P = 0.99). Conclusion: Hypertension causes a delay in HRR after the maximal exercise test yet the exercise training normalizes HRR during the post-exercise period in hypertensive patients.