Previous studies have suggested that exercise training improves cardiac autonomic drive in young and middle-aged adults. In this study, we discuss the benefits for the elderly. We aimed to establish whether exercise still increases heart rate variability (HRV) beyond the age of 60 years, and to identify which training factors influence HRV gains in this population. Interventional controlled and non-controlled studies were selected from the PubMed, Ovid, Cochrane and Google Scholar databases. Only interventional endurance training protocols involving healthy subjects aged 60 years and over, and measuring at least one heart rate global or parasympathetic index, such as the standard deviation of the normal-to-normal intervals (SDNN), total frequency power (Ptot), root mean square of successive differences between adjacent NN intervals (RMSSD), or high frequency power (HF) before and after the training intervention, were included. HRV parameters were pooled separately from short-term and 24 h recordings for analysis. Risks of bias were assessed using the Methodological Index for Non-Randomized Studies and the Cochrane risk of bias tool. A random-effects model was used to determine effect sizes (Hedges’ g) for changes, and heterogeneity was assessed using Q and I statistics. Twelve studies, seven of which included a control group, including 218 and 111 subjects, respectively (mean age 69.0 ± 3.2 and 68.6 ± 2.5), were selected for meta-analysis. Including the 12 studies demonstrated homogeneous significant effect sizes for short-term (ST)-SDNN and 24 h-SDNN, with effect sizes of 0.366 (95% CI 0.185–547) and 0.442 (95% CI 0.144–0.740), respectively. Controlled study analysis demonstrated homogeneous significant effect sizes for 24 h-SDNN with g = 0.721 (95% CI 0.184–1.257), and 24 h-Ptot with g = 0.731 (95% CI 0.195–1.267). Meta-regression analyses revealed positive relationships between ST-SDNN effect sizes and training frequency (
 $${\text{Tau}}_{\text{res}}^{2}$$
  = 0.000; $$I_{\text{res}}^{2}$$
  = 0.000; p = 0.0462). This meta-analysis demonstrates a positive effect of endurance-type exercise on autonomic regulation in older adults. However, the selected studies expressed some risks of bias. We conclude that chronic endurance exercise leads to HRV improvements in a linear frequency–response relationship, encouraging the promotion of high-frequency training programmes in older adults.

Exercise Frequency Determines Heart Rate Variability Gains in Older People: A Meta-Analysis and Meta-Regression.

Pathophysiological Mechanisms in Cardiorenal Syndrome.

This study evaluates the effects of chronic treatment with EET-A, an orally active epoxyeicosatrienoic acid (EETs) analog, on the course of aorto-caval fistula (ACF)-induced heart failure (HF) in Ren-2 transgenic rats (TGR), a model characterized by hypertension and augmented activity of the renin-angiotensin system (RAS). The results were compared with standard pharmacological blockade of the RAS using angiotensin-converting enzyme inhibitor (ACEi). The rationale for employing EET-A as a new treatment approach is based on our findings that apart from increased RAS activity, untreated ACF TGR also shows kidney and left ventricle (LV) tissue deficiency of EETs. Untreated ACF TGR began to die 17 days after creating ACF and were all dead by day 84. The treatment with EET-A alone or ACEi alone improved the survival rate: in 156 days after ACF creation, it was 45.5% and 59.4%, respectively. The combined treatment with EET-A and ACEi appeared to improve the final survival to 71%; however, the difference from either single treatment regimen did not reach significance. Nevertheless, our findings support the notion that targeting the cytochrome P-450-dependent epoxygenase pathway of arachidonic acid metabolism should be considered for the treatment of HF.

Effects of Epoxyeicosatrienoic Acid-Enhancing Therapy on the Course of Congestive Heart Failure in Angiotensin II-Dependent Rat Hypertension: From mRNA Analysis towards Functional In Vivo Evaluation

Objective. To identify associations of beta-adrenoreactivity with stage of chronic heart failure (CHF) in patient with previousmyocardial infarction (MI).Material and Methods. A total of 50 patients with CHF underwent an analysis of adrenoreactivity based on the changes in red blood cellosmoresistance in the presence of adrenergic blocker to determine the activity of the sympathoadrenal system a year after MI.Results. Higher levels of beta-adrenoreactivity (β-ARM) were characteristic of patients with CHF of higher gradations: 61.8(47.5;74.8) с.u. in patients with stage IIA CHF versus 48.7 (39;65.2) с.u. in patients with stage I CHF, p=0.037.Conclusion. These results may suggest the diagnostic value of the indicator of adrenoreactivity and its possible use as a newbiomarker for assessing the severity of CHF in patients with previous myocardial infarction.

/pdf/association-of-adrenoreactivity-with-the-stage-of-chronic-1gjij5jp71.pdf

Association of adrenoreactivity with the stage of chronic heart failure in patients with previous myocardial infarction

Цель исследования – разработка трансляционной модели хронической сердечной недостаточности (ХСН) у крыс, позволяющей, с одной стороны, изучить тонкие механизмы, лежащие в основе данной патологии, а с другой стороны, выявить новые биомишени для поиска и изучения механизма действия инновационных лекарственных средств. Методика. Использован комплекс эхокардиографических, морфологических, биохимических и молекулярно-биологических исследований, позволяющий оценивать и дифференцировать этапы формирования ХСН. Результаты. Динамические эхокардиографические исследования показали, что ХСН формируется через 90 дней после воспроизведения переднего трансмурального инфаркта миокарда. К этому времени у животных основной группы отмечается статистически значимое по сравнению со 2-ми сут. после воспроизведения экспериментального инфаркта миокарда снижение ФВ левого желудочка сердца (соответственно 55,9 ± 1,4 и 63,9 ± 1,6 %, р = 0,0008). Снижение насосной функции сердца (на 13% по сравнению со 2-ми сут. после операции и ≈ на 40% по сравнению с интактными животными) сопровождается увеличением КСР и КДР (соответственно с 2,49 ± 0,08 до 3,91 ± 0,17 мм, р = 0,0002, и с 3,56 ± 0,11 до 5,20 ± 0,19 мм, р = 0,0001), то есть к этому сроку развивается дилатационная сердечная недостаточность. Результаты эхокардиографических исследований подтверждены данными морфометрии миокарда, продемонстрировавшими дилатацию правого и левого желудочков сердца. Параллельно проведенные гистологические исследования свидетельствуют о наличии патогномоничных для данной патологии изменений миокарда (постинфарктный кардиосклероз, компенсаторная гипертрофия кардиомиоцитов, очаги исчезновения поперечной исчерченности мышечных волокон и т.д.) и признаков венозного застоя в легких и печени. Биохимические исследования выявили значимое увеличение концентрации в плазме крови биохимического маркера ХСН – мозгового натрийуретического пептида. Данные молекулярно-биологических исследований позволяют говорить о наличии гиперактивности ренин–ангиотензин–альдостероновой и симпатоадреналовой систем, играющих ключевую роль в патогенезе ХСН. Заключение. Разработана трансляционная модель ХСН у крыс, воспроизводящая основные клинико-диагностические критерии этого заболевания. Показано наличие корреляции между морфометрическими, гистологическими, биохимическими и молекулярными маркерами прогрессирующей ХСН и эхокардиографическими диагностическими признаками, что позволяет использовать неинвазивный метод эхокардиографии, характеризующий состояние внутрисердечной гемодинамики, в качестве основного критерия оценки наличия/отсутствия данной патологии.

Трансляционная модель хронической сердечной недостаточноcти у крыс

Pathophysiologic Mechanisms in Heart Failure: Role of the Sympathetic Nervous System.

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Pathophysiologic Mechanisms in Heart Failure: Role of the Sympathetic Nervous System.