Exercise training corrects control of spontaneous calcium waves in hearts from myocardial infarction heart failure rats

Impaired cardiac control of intracellular diastolic Ca<sup>2+</sup> gives rise to arrhythmias. Whereas exercise training corrects abnormal cyclic Ca<sup>2+</sup> handling in heart failure, the effect on diastolic Ca<sup>2+</sup> remains unstudied. Here, we studied the effect of exercise training on the generation and propagation of spontaneous diastolic Ca<sup>2+</sup> waves in failing cardiomyocytes. Post-myocardial infarction heart failure was induced in Sprague–Dawley rats by coronary artery ligation. Echocardiography confirmed left ventricular infarctions of 40 ± 5%, whereas heart failure was indicated by increased left ventricular end-diastolic pressures, decreased contraction-relaxation rates, and pathological hypertrophy. Spontaneous Ca<sup>2+</sup> waves were imaged by laser linescanning confocal microscopy (488 nm excitation/505–530 nm emission) in 2 μM Fluo-3-loaded cardiomyocytes at 37°C and extracellular Ca<sup>2+</sup> of 1.2 and 5.0 mM. These studies showed that spontaneous Ca<sup>2+</sup> wave frequency was higher at 5.0 mM than 1.2 mM extracellular Ca<sup>2+</sup> in all rats, but failing cardiomyocytes generated 50% (P < 0.01) more waves compared to sham-operated controls at Ca<sup>2+</sup> 1.2 and 5.0 mM. Exercise training reduced the frequency of spontaneous waves at both 1.2 and 5.0 mM Ca2+ (P< 0.05), although complete normalization was not achieved. Exercise training also increased the aborted/completed ratio of waves at 1.2 mM Ca<sup>2+</sup> (P < 0.01), but not 5.0 mM. Finally, we repeated these studies after inhibiting the nitric oxide synthase with L-NAME. No differential effects were found; thus, mediation did not involve the nitric oxide synthase. In conclusion, exercise training improved the cardiomyocyte control of diastolic Ca<sup>2+</sup> by reducing the Ca<sup>2+</sup> wave frequency and by improving the ability to abort spontaneous Ca<sup>2+</sup> waves after their generation, but before cell-wide propagation

Implantable devices for heart failure monitoring: the CardioMEMS™ system.

Several devices have been developed for heart failure (HF) treatment and monitoring. Among device-based monitoring tools, CardioMEMS™ has received growing research attention. This document reflects the key points of an ESC consensus meeting on implantable devices for monitoring in HF, with a particular focus on CardioMEMS™

Molecular and cellular mechanisms of skeletal muscle atrophy: an update

Abstract Skeletal muscle atrophy is defined as a decrease in muscle mass and it occurs when protein degradation exceeds protein synthesis. Potential triggers of muscle wasting are longterm immobilization, malnutrition, severe burns, aging as well as various serious and often chronic diseases, such as chronic heart failure, obstructive lung disease, renal failure, AIDS, sepsis, immune disorders, cancer, and dystrophies. Interestingly, a cooperation between several pathophysiological factors, including inappropriately adapted anabolic (e.g., growth hormone, insulin-like growth factor 1) and catabolic proteins (e.g., tumor necrosis factor alpha, myostatin), may tip the balance towards muscle-specific protein degradation through activation of the proteasomal and autophagic systems or the apoptotic pathway. Based on the current literature, we present an overview of the molecular and cellular mechanisms that contribute to muscle wasting. We also focus on the multifacetted therapeutic approach that is currently employed to prevent the development of muscle wasting and to counteract its progression. This approach includes adequate nutritional support, implementation of exercise training, and possible pharmacological compounds

Aerobic interval training and continuous training equally improve aerobic exercise capacity in patients with coronary artery disease:The SAINTEX-CAD study

AbstractBackgroundExercise-based cardiac rehabilitation increases peak oxygen uptake (peak VO2), which is an important predictor of mortality in cardiac patients. However, it remains unclear which exercise characteristics are most effective for improving peak VO2 in coronary artery disease (CAD) patients. Proof of concept papers comparing Aerobic Interval Training (AIT) and Moderate Continuous Training (MCT) were conducted in small sample sizes and findings were inconsistent and heterogeneous. Therefore, we aimed to compare the effects of AIT and Aerobic Continuous Training (ACT) on peak VO2, peripheral endothelial function, cardiovascular risk factors, quality of life and safety, in a large multicentre study.MethodsTwo-hundred CAD patients (LVEF >40%, 90% men, mean age 58.4±9.1years) were randomized to a supervised 12-week cardiac rehabilitation programme of three weekly sessions of either AIT (90–95% of peak heart rate (HR)) or ACT (70–75% of peak HR) on a bicycle. Primary outcome was peak VO2; secondary outcomes were peripheral endothelial function, cardiovascular risk factors, quality of life and safety.ResultsPeak VO2 (ml/kg/min) increased significantly in both groups (AIT 22.7±17.6% versus ACT 20.3±15.3%; p-time<0.001). In addition, flow-mediated dilation (AIT+34.1% (range –69.8 to 646%) versus ACT+7.14% (range –66.7 to 503%); p-time<0.001) quality of life and some other cardiovascular risk factors including resting diastolic blood pressure and HDL-C improved significantly after training. Improvements were equal for both training interventions.ConclusionsContrary to earlier smaller trials, we observed similar improvements in exercise capacity and peripheral endothelial function following AIT and ACT in a large population of CAD patients

Considering the feasibility, tolerability and safety of high-intensity interval training as a novel treatment for patients with intermittent claudication

Considering the Feasibility, Tolerability and Safety of High-Intensity Interval Training as a Novel Treatment for Patients with Intermittent Claudication.Structured AbstractPurpose: This study assessed the feasibility, tolerability, safety and potential efficacy of a novel, 6-week, high-intensity interval training (HIIT) programme for patients with intermittent claudication (IC).Methods: Patients referred to a usual-care supervised exercise programme were invited to undertake a HIIT programme. All recruited patients performed a baseline cardiopulmonary exercise test (CPX) to inform their exercise prescription. HIIT involved ten, one-minute high-intensity cycling intervals interspersed with one-minute recovery intervals, performed three times per week for six-weeks. Outcomes included feasibility, tolerability, safety, walking distance and quality of life. Results: 144 patients with IC were referred, 95 met initial eligibility criteria (66%) and 30 (32%) were recruited for HIIT, of which 15 (50%) completed. Of the recruited patients, 90% were on optimal medical therapy and 40% had concomitant cardiac, cerebrovascular and/or respiratory disease. Patients who completed the programme attended 100% of the sessions and one serious adverse event was recorded. Improvements in walking distances and quality of life were observed.Following recruitment of the first 20 patients, the inclusion criteria was refined on the basis of CPX, leading to improved completion rates.Conclusions: This study provides preliminary findings indicating that patients with IC can complete a short-term HIIT programme. We provide very early evidence that HIIT may be safe and well-tolerated. In addition, walking distances seem to improve following HIIT. After a small change in the exclusion criteria, the intervention and inclusion/exclusion criteria now seem appropriate for this population, meaning further research to evaluate HIIT in patients with IC is warranted. Condensed abstractThis study considered the safety, feasibility and tolerability of high-intensity interval training (HIIT) for patients with intermittent claudication. Following a small change in the exclusion criteria, patients with intermittent claudication can complete HIIT and it appears well-tolerated and seems to provide improvements in walking distances