Myocardial performance index as a measure of global left ventricular function improves following isometric exercise training in hypertensive patients

As the leading cause of cardiovascular disease and mortality, hypertension remains a global health problem. Isometric exercise training (IET) has been established as efficacious in reducing resting blood pressure (BP); however, no research to date has investigated its effects on the myocardial performance index (MPI). Twenty-four unmedicated hypertensive patients were randomized to 4 weeks of IET and a control period in a crossover design. Tissue Doppler imaging was used to acquire cardiac time intervals pre- and post-IET and during the control periods. IET significantly improved all measures of cardiac time intervals, including isovolumic relaxation time (83.1 ± 10.3 vs. 76.1 ± 11.2 ms, p = 0.006), isovolumic contraction time (84.8 ± 10.3 vs. 72.8 ± 6.4 ms, p < 0.001), ejection time (304.6 ± 30.2 vs. 321.4 ± 20.8 ms, p = 0.015) and the MPI (0.56 ± 0.09 vs. 0.47 ± 0.05, p < 0.001). This is the first study to demonstrate that IET significantly improves cardiac time intervals. These findings may have important clinical implications, highlighting the potential utility of IET in the management of cardiac health in hypertensive patients

Myocardial performance index as a measure of global left ventricular function improves following isometric exercise training in hypertensive patients

As the leading cause of cardiovascular disease and mortality, hypertension remains a global health problem. Isometric exercise training (IET) is established as efficacious in reducing resting blood pressure (BP); however, no research to date has investigated its effects on myocardial performance index (MPI). 24 unmedicated hypertensive patients were randomised to 4-weeks of IET and a control period in a cross-over design. Tissue doppler imaging was used to acquire cardiac time intervals pre and post the IET and control periods. IET significantly improved all measures of cardiac time intervals, including isovolumic relaxation time (83.1±10.3 vs 76.1±11.2ms, p=0.006), isovolumic contraction time (84.8±10.3 vs 72.8±6.4ms, p<0.001), ejection time (304.6±30.2 vs 321.4±20.8ms, p=0.015) and MPI (0.56±0.09 vs 0.47±0.05, p<0.001). This is the first study to demonstrate that IET significantly improves cardiac time intervals. These findings may have important clinical implications, highlighting the potential utility of IET in the management of cardiac health in hypertensive patients

The effect of isometric exercise training on arterial stiffness: a randomised crossover controlled study

Isometric exercise training (IET) is an effective intervention for the management of resting blood pressure (BP). However, the effects of IET on arterial stiffness remain largely unknown. Eighteen unmedicated physically inactive participants were recruited. Participants were randomly allocated in a cross-over design to 4-weeks of home-based wall squat IET and control period, separated by a 3-week washout period. Continuous beat-to-beat haemodynamics, including early and late systolic (sBP 1 and sBP 2, respectively) and diastolic blood pressure (dBP) were recorded for a period of 5-minutes and waveforms were extracted and analysed to acquire the augmentation index (AIx) as a measure of arterial stiffness. sBP 1 (-7.7±12.8 mmHg, p=0.024), sBP 2 (-5.9±9.9 mmHg, p=0.042) and dBP (-4.4±7.2mmHg, p=0.037) all significantly decreased following IET compared to the control period. Importantly, there was a significant reduction in AIx following IET (-6.6±14.5%, p=0.02) compared to the control period. There were also adjacent significant reductions in total peripheral resistance (-140.7±65.8 dyne·s·cm-5, p=0.042) and pulse pressure (-3.8±4.2, p=0.003) compared to the control period. This study demonstrates an improvement in arterial stiffness following a short-term IET intervention. These findings have important clinical implications regarding cardiovascular risk. Mechanistically, these results suggest that reductions in resting BP following IET are induced via favourable vascular adaptations, although the intricate details of such adaptations are not yet clear

Ambulatory blood pressure adaptations to high-intensity interval training: A randomized controlled study

Objective: Hypertension remains the leading cause of cardiovascular disease and premature mortality globally. Although high-intensity interval training (HIIT) is an effective nonpharmacological intervention for the reduction of clinic blood pressure (BP), very little research exists regarding its effects on ambulatory BP. The aim of this study was to measure alterations in ambulatory and clinic BP following HIIT in physically inactive adults. Methods: Forty-one participants (22.8 ± 2.7 years) were randomly assigned to a 4-week HIIT intervention or control group. The HIIT protocol was performed on a cycle ergometer set against a resistance of 7.5% bodyweight and consisted of 3 × 30-s maximal sprints separated with 2-min active recovery. Clinic and ambulatory BP was recorded pre and post the control period and HIIT intervention. Results: Following the HIIT intervention, 24-h ambulatory BP significantly decreased by 5.1 mmHg in sBP and 2.3 mmHg in dBP (P = 0.011 and 0.012, respectively), compared with the control group. In addition, clinic sBP significantly decreased by 6.6 mmHg compared with the control group (P = 0.021), with no significant changes in dBP and mean BP (mBP). Finally, 24-h ambulatory diastolic, daytime sBP, mBP and dBP, and night-time sBP and mBP variability significantly decreased post-HIIT compared with the control group. Conclusion: HIIT remains an effective intervention for the management of BP. Our findings support enduring BP reduction and improved BP variability, which are important independent risk factors for cardiovascular disease

Left atrial mechanics and aortic stiffness following high intensity interval training: a randomised controlled study [Abstract]

Purpose: High intensity interval training (HIIT) has been shown to improve important health parameters, including aerobic capacity, blood pressure, cardiac autonomic modulation and left ventricular (LV) mechanics. However, adaptations in left atrial (LA) mechanics and aortic stiffness remain unclear. Methods: Forty-one physically inactive males and females were recruited. Participants were randomised to either a 4-week HIIT intervention (n=21) or 4-week control period (n=20). The HIIT protocol consisted of 3x30-second maximal cycle ergometer sprints with a resistance of 7.5% body weight, interspersed with 2-minutes of active unloaded recovery, 3 times per week. Speckle tracking imaging of the LA and M-Mode tracing of the aorta was performed pre and post HIIT and control period. Results: Following HIIT, there was significant improvement in LA mechanics, including LA reservoir (13.9±13.4%, p=0.033), LA conduit (8.9±11.2%, p=0.023) and LA contractile (5±4.5%, p=0.044) mechanics compared to the control condition. In addition, aortic distensibility (2.1±2.7cm2dyn-1103, p=0.031) and aortic stiffness index (-2.6±4.6, p=0.041) were improved compared to the control condition. In stepwise linear regression analysis, aortic distensibility change was significantly associated with LA stiffness change R2 of 0.613 (p=0.002). Conclusion: A short-term programme of HIIT was associated with a significant improvement in LA mechanics and aortic stiffness. These adaptations may have important health implications and contribute to the improved LV diastolic and systolic mechanics, aerobic capacity and blood pressure previously documented following HIIT

Left Atrial Mechanics Following Preeclamptic Pregnancy.

BACKGROUND: Preterm preeclampsia is a pregnancy complication associated with myocardial dysfunction and premature cardiovascular disease morbidity and mortality. Left atrial (LA) strain is a noninvasive index of left ventricular end diastolic pressure and an early marker of heart failure risk. This study aimed to evaluate LA strain during the postpartum period in participants with and without preterm preeclampsia and to assess whether this varied in the presence of hypertension and/or cardiac dysfunction. METHODS: In this longitudinal cohort study, 321 women from 28 hospitals with preterm preeclampsia (cases) underwent cardiovascular assessment 6 months postpartum. This is a secondary analysis of the PHOEBE study (ISRCTN01879376). An uncomplicated pregnancy control group (n=30) was recruited from a single center for comparison. A full cross-sectional transthoracic echocardiogram was performed, and from these images, the myocardial strain of the left atrium, including reservoir, conduit, and contractile strain, as well as LA stiffness, were calculated. RESULTS: At 6 months postpartum, compared with controls, prior preeclampsia was associated with a significantly attenuated LA reservoir, conduit, and contractile strain, as well as increased LA stiffness (all P<0.001). LA strain was further reduced in preeclamptic women who had and had not developed hypertension, systolic, or diastolic dysfunction at 6 months postpartum (all P<0.05). CONCLUSIONS: LA mechanics were significantly attenuated at 6 months postpartum in participants with preterm preeclampsia, whether or not they remained hypertensive or had evidence of ventricular dysfunction. Further studies are needed to determine whether postnatal LA strain may identify women at greater risk for future cardiovascular disease

Diagnosis of patients with heart failure with preserved ejection fraction in primary care: cohort study

Objectives: Heart Failure with preserved Ejection Fraction (HFpEF) accounts for half of all heart failure (HF), but low awareness and diagnostic challenges hinder identification in primary care. Our aims were to evaluate the recruitment and diagnostic strategy in the Optimise-HFpEF cohort and compare with recent recommendations for diagnosing HFpEF. Methods: Patients were recruited from 30 primary care practices in two regions in England using an electronic screening algorithm, and two secondary care sites. Baseline assessment collected clinical and patient-reported data and diagnosis by history, assessment and trans-thoracic echocardiogram (TTE). A retrospective evaluation compared study diagnosis with H2FPEF score and HFA-PEFF diagnostic algorithm. Results: 152 patients (86% primary care, mean age 78.5, 40% female) were enrolled; 93 (61%) had HFpEF confirmed. Most participants had clinical features of HFpEF, but those with confirmed HFpEF were more likely female, obese, functionally impaired and symptomatic. Some echocardiographic findings were diagnostic for HFpEF but no difference in natriuretic peptide levels were observed. The H2FPEF and HFA-PEFF scores were not significantly different by group, although confirmed HFpEF cases were more likely to have scores indicating high probability of HFpEF. Conclusions: Patients with HFpEF in primary care are difficult to identify and greater awareness of the condition, with clear diagnostic pathways and specialist support, are needed. Use of diagnostic algorithms and scores can provide systematic approaches to diagnosis but may be challenging to apply in older multi-morbid patients. Where diagnostic uncertainty remains, pragmatic decisions are needed regarding the value of additional testing versus management of presumptive HFpEF.NIHR School for Primary Care Research: Grant #384 NIHR Cambridge Biomedical Research Centre (BRC-1215-20014) and conducted at and supported by the NIHR Cambridge Clinical Research Facilit

Phytochemicals from fern species: potential for medicine applications

Ferns are an important phytogenetic bridge between lower and higher plants. Historically they have been used in many ways by humans, including as ornamental plants, domestic utensils, foods, and in handicrafts. In addition, they have found uses as medicinal herbs. Ferns produce a wide array of secondary metabolites endowed with different bioactivities that could potentially be useful in the treatment of many diseases. However, there is currently relatively little information in the literature on the phytochemicals present in ferns and their pharmacological applications, and the most recent review of the literature on the occurrence, chemotaxonomy and physiological activity of fern secondary metabolites was published over 20 years ago, by Soeder (Bot Rev 51:442\u2013536, 1985). Here, we provide an updated review of this field, covering recent findings concerning the bioactive phytochemicals and pharmacology of fern species