On-treatment comparison between corrective His bundle pacing and biventricular pacing for cardiac resynchronization: A secondary analysis of His-SYNC

Background The His-SYNC pilot trial was the first randomized comparison between His bundle pacing in lieu of a left ventricular lead for cardiac resynchronization therapy (His-CRT) and biventricular pacing (BiV-CRT), but was limited by high rates of crossover. Objective To evaluate the results of the His-SYNC pilot trial utilizing treatment-received (TR) and per-protocol (PP) analyses. Methods The His-SYNC pilot was a multicenter, prospective, single-blinded, randomized, controlled trial comparing His-CRT vs BiV-CRT in patients meeting standard indications for CRT (eg, NYHA II–IV patients with QRS >120 ms). Crossovers were required based on prespecified criteria. The primary endpoints analyzed included improvement in QRS duration, left ventricular ejection fraction (LVEF), and freedom from cardiovascular (CV) hospitalization and mortality. Results Among 41 patients enrolled (aged 64 ± 13 years, 38% female, LVEF 28%, QRS 168 ± 18 ms), 21 were randomized to His-CRT and 20 to BiV-CRT. Crossover occurred in 48% of His-CRT and 26% of BiV-CRT. The most common reason for crossover from His-CRT was inability to correct QRS owing to nonspecific intraventricular conduction delay (n = 5). Patients treated with His-CRT demonstrated greater QRS narrowing compared to BiV (125 ± 22 ms vs 164 ± 25 ms [TR], P < .001;124 ± 19 ms vs 162 ± 24 ms [PP], P < .001). A trend toward higher echocardiographic response was also observed (80 vs 57% [TR], P = .14; 91% vs 54% [PP], P = .078). No significant differences in CV hospitalization or mortality were observed. Conclusions Patients receiving His-CRT on-treatment demonstrated superior electrical resynchronization and a trend toward higher echocardiographic response than BiV-CRT. Larger prospective studies may be justifiable with refinements in patient selection and implantation techniques to minimize crossovers

Integrated platform for detecting pathogenic DNA via magnetic tunneling junction-based biosensors

In recent years, the development of portable platforms for performing fast and point-of-care analyses has drawn considerable attention for their wide variety of applications in life science. In this framework, tools combining magnetoresistive biosensors with magnetic markers have been widely studied in order to detect concentrations of specific molecules, demonstrating high sensitivity and ease of integration with conventional electronics. In this work, first, we develop a protocol for efficient hybridization of natural DNA; then, we show the detection of hybridization events involving natural DNA, namely genomic DNA extracted from the pathogenic bacterium Listeria monocytogenes, via a compact magnetic tunneling junction (MTJ)-based biosensing apparatus. The platform comprises dedicated portable electronic and microfluidic setups, enabling point-of-care biological assays. A sensitivity below the nM range is demonstrated. This work constitutes a step forward towards the development of portable lab-on-chip platforms, for the multiplexed detection of pathogenic health threats in food and food processing environment

Membranous IVC obstruction presenting with antegrade/retrograde respiratory flow in the intrahepatic segment in Doppler imaging and prostatic and urethral congestion

BACKGROUND: Obstruction of the inferior vena cava (IVC) is infrequent, membranous obstruction of the IVC (MOIVC) being one of its rare causes. Early diagnosis is important, as it can lead to hepatic congestion, cirrhosis and Budd-Chiari syndrome (BCS) and can predispose to development of hepatocellular carcinoma (HCC) in severe cases. CASE REPORT: We report a case of membranous IVC obstruction at the junction of hepatic and suprahepatic segments in a young male with extensive collateralization and venous aneurysms. Unique findings involved antegrade and retrograde flow during respiration in the upper part of intrahepatic IVC proximal to a large collateral vein as well as prostatic and urethral congestion leading to intermittent urinary hesitancy, which have not yet been described in such cases. CONCLUSIONS: MOIVC is a rare cause of IVC obstruction with typical radiological features. Early diagnosis and management is required due to risk of cirrhosis and HCC. Antegrade and retrograde flow may be seen in incomplete MOIVC above the level of a large collateral vein and it may lead to prostatic and urethral congestion

Root cause analysis of bucket stage III OF GT-2A

In the present study, examination of fractured gas turbine blades (stage III of GT-2A) with identification numbers 23, 39, 40, 49, 453 and 485 was carried out by different characterization methods. Extensive SEM fractography studies on all the fractured surfaces of ruptured blades indicated that surface crack initiation and propagation at the leading edge was by fatigue mechanism as evidenced by striations, rubbing marks and secondary cracks (which are characteristic features of normal fatigue) whereas the crack propagated thereafter through inter-dendritic/inter-granular path as evidenced by large amount of interdendritic/intergranular facets. Since no corrosion products were found on the pressure side/suction side surfaces, it was believed that hot corrosion was not responsible for the present failure. Further, no features like impact with a foreign object were found thus ruling out the possibility of FOD (foreign object damage). Microstructural characterization revealed that there were some significant changes/damages in the microstructure of these blades after service exposure (but these changes alone cannot result in creep failure). Almost all blades, exhibited gamma prime dissolution band at both concave and convex surfaces, in addition to coarsening of gamma/gamma prime, formation of chain of precipitates, coarsening of precipitates. Though the hardness tests indicated considerable hardening effect due to ageing of these blades at high temperatures over a period of time (further ruling out the creep phenomena as the cause of failure), the stress rupture tests did not reveal any significant reduction in the stress rupture life. Based on the results obtained in the present investigation, it can be concluded that the blades were subjected to surface overheating (above the gamma prime dissolution temperature) for a very short period of time. Because of this, the surface edges lost the gamma prime (i.e. dissolved into the gamma matrix). This is a serious problem because all the mechanical properties would be impaired if the precipitates of gamma prime are dissolved into the matrix at surface. Due to this, fatigue cracks were initiated at the leading edge surfaces and further propagated by inter-dendritic/inter-granular (IG) fracture mechanism. No creep/hot corrosion/FOD was noticed. Therefore the primary cause of failure was surface overheating for a very short period of time and the secondary cause of failure is normal fatigue followed by IG cracking

Permanent conduction system pacing for congenitally corrected transposition of the great arteries: A Pediatric and Congenital Electrophysiology Society (PACES)/International Society for Adult Congenital Heart Disease (ISACHD) Collaborative Study

Background Congenitally corrected transposition of the great arteries (CCTGA) is associated with spontaneous atrioventricular block and pacing-induced cardiomyopathy. Conduction system pacing is a potential alternative to conventional cardiac resynchronization therapy (CRT). Objective The purpose of this study was to determine the outcomes of conduction system pacing for CCTGA. Methods Retrospective data were collected from 10 international centers. Results His bundle (HBP) or left bundle branch pacing (LBBP) was attempted in 15 CCTGA patients (median age 23 years; 87% male). Previous surgery had been performed in 8 and chronic ventricular pacing in 7. Conduction system pacing (11 HBP, 2 LBBP 2; nonselective in 10, selective in 3) was acutely successful in 13 (86%) without complication. In 9 cases, electroanatomic mapping was available and identified the distal His bundle and proximal left bundle branches within the morphologic left ventricle below the pulmonary valve separate from the mitral annulus. Median implant HV interval was 42 ms (interquartile range [IQR] 35–48), R wave 6 mV (IQR 5–18), and threshold 0.5 V (IQR 0.5–1.2) at median 0.5 ms. QRSd was unchanged compared to junctional escape rhythm (124 vs 110 ms; P = .17) and decreased significantly compared to baseline ventricular pacing (112 vs 164 ms; P <.01). At a median of 8 months, all patients were alive without significant change in pacing threshold or lead dysfunction. New York Heart Association functional class improved in 5 patients. Conclusion Permanent conduction system pacing is feasible in CCTGA by either HBP or proximal LBBP. Narrow paced QRS and stable lead thresholds were observed at intermediate follow-up. Unique anatomic characteristics may favor this approach over conventional CRT