Bi-Ventricular Myocardial Performance in Heart Failure: A New Approach to Evaluate Interventricular Dyssynchrony

Aims: Patients with heart failure (HF) exhibit ventricular dyssynchrony with negative effects on ventricular systolic and diastolic performance and poor prognosis. There is no consensus about the best approach for estimating the dyssynchrony and for selecting candidates for resynchronization therapy (CRT). We sought to evaluate whether Myocardial Performance Index (MPI), calculated as differences between left and right ventricle (LV, RV), ΔMPI, represents a marker of interventricular dyssynchrony. Methods: The study included 40 patients (22 males, 18 females, mean age 71±13) with NYHA functional class II-III, chronic heart failure (77% ischaemic), in optimal drug therapy for at least three months. All patients underwent a complete two-dimensional and Tissue Doppler Echocardiography (TDE), including an assessment of MPI in both ventricles. Results: Significant correlations were found between ΔMPI and QRS (r = 0.41, p < 0.001), with NYHA (r = 0.66, p < 0.001), with SPWMD (r = 0.32, p < 0.05), with LV ejection fraction (r = -0.32, p < 0.05), with Spv wave at the septal site of LV (r = -0.32, p < 0.05), and with IVMD (r = 0.44, p < 0.001). Ten patients have been re-evaluated six months after CRT implantation, and ΔMPI significantly correlated with the difference between basal LVEF and six months after CRT implantation (r = 0.43, p < 0.04). Conclusion: The ΔMPI could represent an integrative marker of interventricular dyssynchrony and could be considered as a new parameter in the patient selection process to be undergone CRT

Role of the sympathetic nervous system during the development of obesity-induced hypertension in rabbits

We have previously reported that weight gain induced by high-fat diet (HFD) leads to an increase in mean arterial pressure (MAP, +14%) and heart rate (HR, +31%) in the adult rabbit. In the present study, we tested the hypothesis that an increased activity of the sympathetic nervous system may contribute to the development of obesity-induced hypertension. A combination of α- and β-adrenergic blockers (terazosin + propranolol) was chronically administered to rabbits housed in metabolic cages for continuous monitoring of arterial pressure by telemetry, 24 h a day. After 2 weeks of adrenergic blockade under control diet, animals were switched to HFD for the next 6 weeks. HFD induced a progressive increase in body weight, but no increase in mean arterial pressure (+0.2 ± 2.5%) and a slight increase in heart rate (+14 ± 3%). Time-control animals fed normal diet showed no changes in MAP or HR with long-term α- and β-adrenergic blockade. Our results indicate that the activation of the sympathetic nervous system may play an important role in the pathogenesis of obesity-induced hypertensio

Tenebrio Molitor Meal in Rainbow Trout (Oncorhynchus Mykiss) Diets: Effects on Animal Performance, Nutrient Digestibility and Chemical Composition of Fillets

This study evaluated the effects of diets containing Tenebrio molitor (TM) larvae meal on growth performances, somatic indexes, nutrient digestibility, dorsal muscle proximate and fatty acid (FA) compositions of rainbow trout. Three hundred sixty fish were randomly divided into three groups with four replicates each. The groups were fed diets differing in TM inclusion: 0% (TM0), 25% (TM25) and 50% (TM50) as fed weight basis. Weight gain was not affected by treatment. Feeding rate was significantly higher in TM0 than TM50. Feed conversion ratio was significantly higher in TM0 than TM25 and TM50, while an opposite trend was observed for protein efficiency ratio and specific growth rate. The survival rate was significantly lower in TM0 than TM25 and TM50. The apparent digestibility of protein was significantly lower in the TM50 group than the other groups, while the apparent digestibility of dry matter, organic matter and lipids was unaffected by treatment. If compared to control, the protein and lipid contents of fillets were respectively increased and decreased following TM inclusion in the diet. The Σn3/Σn6 FA ratio of fish dorsal muscle was linearly (TM0>TM25>TM50) reduced by TM inclusion in the diet. Results suggested that TM could be used during the growing phase in trout farming; however, additional studies on specific feeding strategies and diet formulations are needed to limit its negative effects on the lipid fraction of fillets