AV-optimized conduction system pacing for treatment of AV dromotropathy: A randomized, cross-over study.

BACKGROUND: Severe first-degree atrioventricular (AV) block may produce symptoms similar to heart failure due to AV dyssynchrony, a syndrome termed AV dromotropathy. According to guidelines, it should be considered for permanent pacemaker implantation, yet evidence supporting this treatment is scarce. OBJECTIVES: This study aimed to determine the impact of AV-optimized conduction system pacing (CSP) in patients with symptomatic severe first-degree AV block and echocardiographic signs of AV dyssynchrony. METHODS: Patients with symptomatic first-degree AV block (PR > 250 ms), preserved left ventricular ejection fraction, narrow QRS, and AV dyssynchrony were included in the study. In a single-blind cross-over design, patients were randomized to AV sequential CSP or backup VVI pacing with a base rate of 40 bpm. We compared exercise capacity, echocardiographic parameters, and symptom occurrence at the end of 3 months of each period. RESULTS: Fourteen patients completed the study. During the AV-optimized CSP compared to the backup pacing period, patients achieved a higher workload on exercise test (147.2 ± 50.9 vs. 140.7 ± 55.8 W; p = .032), with a trend towards higher peak VO2 (23.3 ± 7.1 vs. 22.8 ± 7.1 mL/min/kg; p = .224), and higher left ventricular stroke volume (LVSV 74.5 ± 13.8 vs. 66.4 ± 12.5 mL; p < .001). Symptomatic improvement was recorded, with fewer patients reporting general tiredness and 71% of patients preferring the AV-optimized CSP (p = .008). CONCLUSIONS: AV-optimized CSP could improve symptoms, exercise capacity and LVSV in patients with severe first-degree AV block.

Impact of preventive substrate catheter ablation on implantable cardioverter-defibrillator interventions in patients with ischaemic cardiomyopathy and infarct-related coronary chronic total occlusion.

AIMS: Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation. METHODS AND RESULTS: The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome's components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12-0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151). CONCLUSION: Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs.

Biventricular versus Conduction System Pacing after Atrioventricular Node Ablation in Heart Failure Patients with Atrial Fibrillation.

Conduction system pacing (CSP) modalities, including His-bundle pacing (HBP) and left bundle branch pacing (LBBP), are increasingly used as alternatives to biventricular (BiV) pacing in heart failure (HF) patients scheduled for pace and ablate strategy. The aim of the study was to compare clinical outcomes of HF patients with refractory AF who received either BiV pacing or CSP in conjunction with atrio-ventricular node ablation (AVNA). Fifty consecutive patients (male 48%, age 70 years (IQR 9), left ventricular ejection fraction (LVEF) 39% (IQR 12)) were retrospectively analysed. Thirteen patients (26%) received BiV pacing, 27 patients (54%) HBP and 10 patients (20%) LBBP. All groups had similar baseline characteristics and acute success rate. While New York Heart. Association (NYHA) class improved in both HBP (p < 0.001) and LBBP (p = 0.008), it did not improve in BiV group (p = 0.096). At follow-up, LVEF increased in HBP (form 39% (IQR 15) to 49% (IQR 16), p < 0.001) and LBBP (from 28% (IQR 13) to 40% (IQR 13), p = 0.041), but did not change in BiV group (p = 0.916). Conduction system pacing modalities showed superior symptomatic and echocardiographic improvement compared to BiV pacing after AVNA. With more stable pacing parameters, LBBP could present a more feasible pacing option compared to HBP.

Determination of the Kinetics and Thermodynamic Parameters of Lignocellulosic Biomass Subjected to the Torrefaction Process.

The torrefaction process upgrades biomass characteristics and produces solid biofuels that are coal-like in their properties. Kinetics analysis is important for the determination of the appropriate torrefaction condition to obtain the best utilization possible. In this study, the kinetics (Friedman (FR) and Kissinger-Akahira-Sunose (KAS) isoconversional methods) of two final products of lignocellulosic feedstocks, miscanthus (Miscanthus x giganteus) and hops waste (Humulus Lupulus), were studied under different heating rates (10, 15, and 20 °C/min) using thermogravimetry (TGA) under air atmosphere as the main method to investigate. The results of proximate and ultimate analysis showed an increase in HHV values, carbon content, and fixed carbon content, followed by a decrease in the VM and O/C ratios for both torrefied biomasses, respectively. FTIR spectra confirmed the chemical changes during the torrefaction process, and they corresponded to the TGA results. The average Eα for torrefied miscanthus increased with the conversion degree for both models (25-254 kJ/mol for FR and 47-239 kJ/mol for the KAS model). The same trend was noticed for the torrefied hops waste samples; the values were within the range of 14-224 kJ/mol and 60-221 kJ/mol for the FR and KAS models, respectively. Overall, the Ea values for the torrefied biomass were much higher than for raw biomass, which was due to the different compositions of the torrefied material. Therefore, it can be concluded that both torrefied products can be used as a potential biofuel source.

Chia Seeds (Salvia hispanica L.): An Overview-Phytochemical Profile, Isolation Methods, and Application.

Chia (Salvia hispanica L.) is a small seed that comes from an annual herbaceous plant, Salvia hispanica L. In recent years, usage of Chia seeds has tremendously grown due to their high nutritional and medicinal values. Chia was cultivated by Mesopotamian cultures, but then disappeared for centuries until the middle of the 20th century, when it was rediscovered. Chia seeds contain healthy ω-3 fatty acids, polyunsaturated fatty acids, dietary fiber, proteins, vitamins, and some minerals. Besides this, the seeds are an excellent source of polyphenols and antioxidants, such as caffeic acid, rosmarinic acid, myricetin, quercetin, and others. Today, chia has been analyzed in different areas of research. Researches around the world have been investigating the benefits of chia seeds in the medicinal, pharmaceutical, and food industry. Chia oil is today one of the most valuable oils on the market. Different extraction methods have been used to produce the oil. In the present study, an extensive overview of the chemical composition, nutritional properties, and antioxidant and antimicrobial activities, along with extraction methods used to produce chia oil, will be discussed.