QTc Interval is Associated with Atrial Fibrillation in Individuals with Metabolic Syndrome Phenotype.

Purpose: Manifestations of metabolic syndrome (MetS) carry risks for atrial fibrillation (AF). The study determined whether any electrocardiographic parameter can reflect increased AF risk in individuals with MetS. Patients and Methods: From our University Hospital database, we examined the presence of AF and its correlation with MetS manifestations, renal function, lipid profiles, and electrocardiographic parameters (P wave duration, PR interval, QRS width, and QTc intervals). Between January 2008 and December 2015, data from 4479 adults (women 41.6% vs men 58.4%) were identified. Results: The overall prevalence of AF was 12.4%, without sex differences (women, 12.8% vs men, 12.1%). Patients with AF were older (age 73.9 ± 11.8 vs non-AF 67 ± 13.5 years), with lower lipid levels (TG, total cholesterol, and LDL-cholesterol, all p < 0.0001), and at lower eGFR level (64.1 ± 30.9 vs non-AF 68.8 ± 41.4 mL/min/1.73m2, p < 0.0001). Besides, sex differences were present in all electrocardiographic parameters (all p < 0.05). Hypertension had the highest odds ratio (1.33; p = 0.026) for AF. Comparing AF to non-AF, the QTc of quartiles was significantly different (p < 0.0089). The shortest and longest QTc quartiles had an increased incidence of AF. Conclusion: AF risk in patients with MetS phenotypes can be reflected by QTc quartiles.

The sodium-glucose co-transporter 2 inhibitor empagliflozin attenuates cardiac fibrosis and improves ventricular hemodynamics in hypertensive heart failure rats.

BACKGROUND: Sodium glucose co-transporter 2 inhibitor (SGLT2i), a new class of anti-diabetic drugs acting on inhibiting glucose resorption by kidneys, is shown beneficial in reduction of heart failure hospitalization and cardiovascular mortality. The mechanisms remain unclear. We hypothesized that SGLT2i, empagliflozin can improve cardiac hemodynamics in non-diabetic hypertensive heart failure. METHODS AND RESULTS: The hypertensive heart failure model had been created by feeding spontaneous hypertensive rats (SHR) with high fat diet for 32 weeks (total n = 13). Half SHRs were randomized to be administered with SGLT2i, empagliflozin at 20 mg/kg/day for 12 weeks. After evaluation of electrocardiography and echocardiography, invasive hemodynamic study was performed and followed by blood sample collection and tissue analyses. Empagliflozin exhibited cardiac (improved atrial and ventricular remodeling) and renal protection, while plasma glucose level was not affected. Empagliflozin normalized both end-systolic and end-diastolic volume in SHR, in parallel with parameters in echocardiographic evaluation. Empagliflozin also normalized systolic dysfunction, in terms of the reduced maximal velocity of pressure incline and the slope of end-systolic pressure volume relationship in SHR. In histological analysis, empagliflozin significantly attenuated cardiac fibrosis in both atrial and ventricular tissues. The upregulation of atrial and ventricular expression of PPARα, ACADM, natriuretic peptides (NPPA and NPPB), and TNF-α in SHR, was all restored by treatment of empagliflozin. CONCLUSIONS: Empagliflozin improves hemodynamics in our hypertensive heart failure rat model, associated with renal protection, attenuated cardiac fibrosis, and normalization of HF genes. Our results contribute some understanding of the pleiotropic effects of empagliflozin on improving heart function.

Simultaneous Electrocardiography Recording and Invasive Blood Pressure Measurement in Rats.

For studies related to cardiovascular physiology or pathophysiology, blood pressure (BP) and electrocardiography are basic observational parameters. Research focusing on cardiovascular disease models, potential cardiovascular therapeutic targets or pharmaceutical agents requires assessment of systemic arterial pressure and heart rhythm changes. In situations where radio telemetry systems are not available or affordable, the technique of femoral artery cannulation is an alternative way to obtain intra-arterial pressure waveform recordings and systemic BP measurements. This technique is economical and can be performed with standard equipment in animal facilities. However, invasive arterial pressure recording requires cannulation of small arteries, which can be a challenging surgical skill. Here, we present step-by-step protocols for femoral artery cannulation procedures. Key procedures include the calibration of the data acquisition system, tissue dissection and femoral artery cannulation, and setup of the arterial cannulation system for pressure recording. Surface electrocardiography recording procedures are also included. We also present examples of BP recordings from normotensive and hypertensive rats. This protocol allows reliable direct recordings of systemic BP with simultaneous electrocardiography.

Cultivation temperature modulated the monomer composition and polymer properties of polyhydroxyalkanoate synthesized by Cupriavidus sp. L7L from levulinate as sole carbon source.

Cupriavidus sp. L7L, a newly isolated wild-type soil bacterium, was found to synthesize polyhydroxyalkanoate (PHA) terpolymers from levulinic acid (LA), a top bio-based platform chemical, as the sole carbon source. NMR spectra showed that the terpolymers consisted mainly of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and a small amount (2.1-4.8 mol%) of 4-hydroxyvalerate (4HV). The combination of monomers together with high molecular weights improved markedly the thermal and mechanical properties of the terpolymers. Increasing cultivation temperature of Cupriavidus sp. L7L increased the proportions of 3HB and decreased the proportions of 3HV. A fed-batch fermentation using LA as the sole carbon source without pH control produced a biomass of 15.8 dry weight g L-1 that contained 81 dry weight% of a terpolymer P(3HB-co-33.7 mol% 3HV-co-2.1 mol% 4HV), equaling a productivity of 0.213 g PHA L-1 h-1. The terpolymer showed a melting point of 92 °C and elongation at break of 630%, compared to 84.6 °C and 462%, respectively, for the copolymer P(3HB-co-35.9 mol% 3HV) that contained no 4HV. This study showed that Cupriavidus sp. L7L exhibited a great potential for producing PHA polymers with excellent mechanical property that could be modulated by cultivation temperature when cultivated exclusively in LA.