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Catalin Pestrea,1– 3 Ecaterina Cicala,1 Alexandra Gherghina,1 Florin Ortan,1 Dana Pop2,3 1Department of Interventional Cardiology, Brasov County Clinical Emergency Hospital, Brasov, 500326, Romania; 2 5th Department of Internal Medicine, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, Cluj-Napoca, 400012, Romania; 3Department of Cardiology, Clinical Rehabilitation Hospital, Cluj-Napoca, 400347, RomaniaCorrespondence: Catalin Pestrea, Brasov County Clinical Emergency Hospital, Brasov, 500326, Romania, Tel +40745003637, Email pestrea.catalin@gmail.comPurpose: Although feasibility studies have included older patients, specific data for His bundle pacing (HBP) in this population is scarce. The aim of this study was to evaluate the feasibility and mid-term performance of HBP in the elderly (70 to 79 years old) versus the very elderly (80 years old and above) patients with conventional indications for pacing.Patients and Methods: About 105 patients older than 70 years of age with attempted HBP from the 1st of January 2019 to the 31st of December 2021 were reviewed. Clinical and procedural characteristics were recorded at baseline, and after a mid-term follow-up period.Results: The procedural success rate was similar in both age groups (68.49% vs 65.62%). There was no significant difference in pacing or sensing thresholds, impedance, and fluoroscopy times. For both age intervals, patients with a baseline narrow QRS maintained a similar QRS duration after pacing, while in patients with a wide QRS, the paced QRS was significantly shorter. Baseline QRS duration, left bundle branch block morphology, and ejection fraction, were significantly associated with HBP procedural failure. The mean follow-up period was 830.34 days for the elderly and 722.76 days for the very elderly. After the follow-up period, both sensing and pacing thresholds were similar between the groups. Compared to the baseline values, there were no significant changes in both pacing and sensing parameters, irrespective of the age interval. During follow-up, no lead dislodgements were recorded. There were two cases of significant pacing threshold rise in the elderly (4%) and three cases in the very elderly group (14.2%) which were managed conservatively, without lead revision.Conclusion: In elderly and very elderly patients, HBP is a feasible procedure associated with constant pacing and sensing parameters and with low complication rates over mid-term follow-up.Keywords: conduction system pacing, elderly and very elderly, feasibility study, mid-term follow-up

His bundle and left bundle branch pacing are regarded as physiological options for permanent ventricular pacing because they use the fast-conducting specialized tissue for depolarization. The development, more than a decade ago, of a dedicated delivery kit using a lumenless lead, revolutionized the procedures and dramatically increased the success rate. After these consistent results, the industry is focusing now on releasing more tools for conduction system pacing.

The Fluorescence Immunoassay and Enzyme-linkedimmunosorbent- assay (ELISA) can be used as an aid in the diagnosis in certain autoimmune diseases, being extremely important in medical practice. The study was conducted on a total of 75 patients registered between 11.11.2011-16.02.2012, in Clinical Emergency Hospital of Brasov. The aims of this paper are highlighting the importance of titration in patients with antinuclear antibodies presents and the importance of ELISA technique for diagnosis of autoimmune diseases. Fluorescence can be used as a screening method for determination of antinuclear antibodies. A positive titer accompanied by the appearance pattern orients us on correct and fast diagnosis. Both fluorescence and ELISA are important for diagnosing and monitoring of autoimmune diseases. [ABSTRACT FROM AUTHOR]

In the aeronautical industry there is an increasing interest in joining At alloy sheets using laser welding techniques rather than the riveting ones. The present paper presents experimental results obtained when laser welding At-Mg-Si sheets in a T-joint configuration (a widely used con- figuration in aircraft construction) with a Nd:YAG laser. By applying the experimental designs method it is possible to define quantitatively the parameters that produce a T-joint with adequate mechanical properties and prevent hot cracking - a phenomenon that frequently occurs in the laser welding of theses alloys. The experimental approach involved two welding techniques: a sequential one, with a successive movement of the laser beam along cacti side of the assembly; and a simultaneous welding technique, with two beams moving simultaneously on both sides of the assembly. The two methods gave different results in terms of seam penetration hut not in terms of ultimate tensile load. In addition, an empirical model was established for the ultimate tensile load of the seams and a technological window for high tensile properties T-joint was determined: welding speeds between 4 and 5 m/mm where fractures were recorded in the base material and a filler wire volume of 0.65 to 0.78 mm3 per mm of weld. The experimental design method allows one to find a more efficient way of determining the optimal domain for complex processes. [ABSTRACT FROM AUTHOR]

Background: Fast-conducting atrial fibrillation misinterpreted as ventricular tachycardia is the leading cause for inappropriate shocks in patients with implantable cardiac defibrillators (ICD). These inappropriate shocks are associated with significant morbidity and mortality and cause great discomfort and stress., Case Presentation: We report the case of a patient with ischemic cardiomyopathy, permanent atrial fibrillation, and a single-chamber DF-1 ICD implanted for the primary prevention of sudden cardiac death, who presented for multiple inappropriate internal shocks due to very fast-conducting atrial fibrillation, which was mislabeled as ventricular fibrillation by the ICD. Since the patient was under maximal atrioventricular nodal blocking medical therapy (beta-blockers and digitalis) and we didn`t find any reversible causes for the heart rate acceleration, we opted for rate control with atrioventricular node ablation. To counteract the risk of pacing-induced cardiomyopathy in this patient who would become totally pacemaker-dependent, we successfully performed left bundle branch area pacing. Because the patient`s ICD had a DF-1 connection and the battery had a long life remaining, we connected the physiological pacing lead to the IS-1 sense-pace port of the ICD. The 6-month follow-up showed an improvement in left ventricular function with no more inappropriate shocks., Conclusions: Left bundle branch area pacing and atrioventricular node ablation in patients with an implantable single-chamber DF-1 defibrillator and fast-conducting permanent atrial fibrillation is a cost-efficient and very effective method to prevent and treat inappropriate shocks, avoiding the use of an additional dual-chamber or CRT-D device., (© 2024. The Author(s).)

Background: The primary prerequisite for a successful conduction system pacing (CSP) procedure is the integrity of the conduction system, which may be impaired if a baseline bundle branch block (BBB) is present. This study aimed to evaluate the feasibility and mid-term performance of permanent CSP in patients with baseline BBB and to compare the results between left bundle branch block (LBBB) and right bundle branch block (RBBB) patterns., Material and Methods: A total of 101 patients with typical BBB and an attempt at CSP were retrospectively reviewed. Procedural characteristics, pacing, sensing parameters, and complications at baseline and after a mid-term follow-up were analyzed., Results: The global procedural success for CSP was 93%. His bundle pacing (HBP) had a significantly lower success rate than left bundle branch area pacing (LBBAP) (50.5% vs. 86%). The paced QRS duration was significantly narrower with HBP. The pacing and sensing thresholds were significantly better with LBBAP. Procedural complications occurred only in the LBBAP group (two acute perforations in the LV cavity and one acute chest pain during lead fixation) without long-term sequelae. The HBP and the LBBAP procedural success rates were higher in the RBBB versus the LBBB group (62.5% vs. 44.9% and 100% vs. 81.5%, respectively). Baseline QRS duration, atrial volumes, and right ventricular diameters were significantly associated with HBP procedural failure. The follow-up pacing and sensing thresholds were similar to the baseline values for all pacing methods and BBB morphology. Only one device-related complication leading to pacing interruption was recorded., Conclusion: In patients with bundle branch blocks, CSP is a feasible procedure associated with a high success rate, stable pacing and sensing parameters, and low complication rates over a mid-term follow-up.

Introduction: This study evaluated the feasibility of His bundle pacing (HBP) in consecutive, unselected patients with advanced atrioventricular block (AVB) over a medium-term follow-up period, comparing procedural characteristics between nodal and infranodal sites of the conduction block., Materials and Methods: Seventy-five consecutive patients with second-degree or third-degree AVB in which HBP was attempted were prospectively included in this study. The clinical and procedural-related characteristics of the patients were recorded at baseline and over a mid-term follow-up., Results: 72% of the patients had normal QRS duration at baseline. Intracardiac electrograms revealed nodal AVB in 46 patients (61.3%). The permanent HBP procedural success was significantly higher in nodal AVB (84.8%) vs infranodal AVB (31%). There was no statistical difference between paced QRS duration, impedance, pacing and sensing thresholds and fluoroscopy time in the two groups. Infranodal block, baseline QRS duration, left bundle branch block morphology and ejection fraction were significantly associated with HBP procedural failure. The patients were followed for a period of 627.71±160.93 days. There were no significant differences in parameters at follow-up. An increase of >1 V in the His bundle (HB) capture threshold was encountered in one patient with infranodal AVB (11.1 %) and in four patients with nodal AVB (10.25%)., Conclusion: Permanent HBP is a feasible pacing technique in nodal AVB with a high success rate and stable thresholds in the medium term. Most infranodal blocks are located within the HB, so there is still the possibility to capture the conduction system, although with lower success rates., Competing Interests: Competing interests: CP has received proctorship fees and travel grants from Medtronic., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Compared with conventional right ventricular septal pacing (RVSP), several studies have shown a net clinical benefit of left bundle branch area pacing (LBBAP) in terms of ejection fraction preservation and reduced hospitalizations for heart failure. The purpose of this study was to compare acute depolarization and repolarization electrocardiographic parameters between LBBAP and RVSP in the same patients during the LBBAP implant procedure. We prospectively included 74 consecutive patients subjected to LBBAP from 1 January to 31 December 2021 at our institution in the study. After the lead was placed deep into the ventricular septum, unipolar pacing was performed and 12-lead ECGs were recorded from the distal (LBBAP) and proximal (RVSP) electrodes. QRS duration (QRSd), left ventricular activation time (LVAT), right ventricular activation time (RVAT), QT and JT intervals, QT dispersion (QTd), T-wave peak-to-end interval (Tpe), and Tpe/QT were measured for both instances. The final LBBAP threshold was a 0.7 ± 0.31 V at 0.4 ms duration with a sensing threshold of 10.7 ± 4.1 mV. RVSP produced a significantly larger QRS complex than the baseline QRS (194.88 ± 17.29 ms vs. 141.89 ± 35.41 ms, p < 0.001), while LBBAP did not significantly change the mean QRSd (148.10 ± 11.52 ms vs. 141.89 ± 35.41 ms, p = 0.135). LVAT (67.63 ± 8.79 ms vs. 95.89 ± 12.02 ms, p < 0.001) and RVAT (80.54 ± 10.94 ms vs. 98.99 ± 13.80 ms, p < 0.001) were significantly shorter with LBBAP than with RVSP. Moreover, all the repolarization parameters studied were significantly shorter in LBBAP than in RVSP (QT-425.95 ± 47.54 vs. 487.30 ± 52.32; JT-281.85 ± 53.66 vs. 297.69 ± 59.02; QTd-41.62 ± 20.07 vs. 58.38 ± 24.44; Tpe-67.03 ± 11.19 vs. 80.27 ± 10.72; and Tpe/QT-0.158 ± 0.028 vs. 0.165 ± 0.021, p < 0.05 for all), irrespective of the baseline QRS morphology. LBBAP was associated with significantly better acute depolarization and repolarization electrocardiographic parameters compared with RVSP.

His bundle pacing (HBP) has several pitfalls, such as the inability to identify the His bundle and lack of capture at acceptable thresholds. The majority of data regarding HBP were obtained using a dedicated non-deflectable delivery system. This study aimed to evaluate the impact of cardiac chamber dimensions on permanent HBP procedural outcomes when using this type of fixed-curve catheter. Seventy-two patients subjected to HBP from the 1st of January to the 31st of December 2021 at our institution were retrospectively reviewed. The baseline clinical characteristics and echocardiographic measurements of all the cardiac chambers were recorded, as well as procedural outcomes (HB electrogram identification and overall procedural success). During the procedure, the HB electrogram was recorded in 59 patients (81.9%) and successful permanent HBP was achieved in 33 patients, representing 45.8% of all the studied patients. Left atrial (LA) and right atrial (RA) volumes were significantly higher in patients without HB electrogram identification. Only LA and RA volumes were statistically associated with HB electrogram localization, while there was no significant association between the echocardiographic parameters and procedural success. LA volumes above 93 mL and RA volumes above 60 mL had an 8.81 times higher chance of failure to localize the HB electrogram compared with patients with lower volumes (p < 0.001). When considering non-deflectable delivery catheters for HBP, careful preprocedural echocardiographic analysis of the atrial volumes could help in the proper selection of implanting tools, thus optimizing the procedural outcomes and costs.