Left bundle branch area pacing prevents pacing induced cardiomyopathy in long-term observation.

BACKGROUND: Left bundle branch area pacing (LBBAP) is one of the methods to deliver conduction system pacing which potentially avoids the negative impact of conventional right ventricular pacing. OBJECTIVE: To assess echocardiographic outcomes in a long-term observation in patients with LBBAP implemented for bradyarrhythmia indications. METHODS AND RESULTS: A total of 151 patients with symptomatic bradycardia and LBBAP pacemaker implanted, were prospectively included in the study. Subjects with left bundle branch block and CRT indications (n = 29), ventricular pacing burden <40% (n = 11), and loss of LBBAP (n = 10) were excluded from further analysis. At baseline and the last follow-up visit, echocardiography with global longitudinal strain (GLS) assessment, 12-lead ECG, pacemaker interrogation, and blood level of NT-proBNP were performed. The median follow-up period was 23 months (15.5-28). None of the analyzed patients fulfilled the criteria for pacing induced cardiomyopathy (PICM). Improvement in left ventricular ejection fraction (LVEF) and GLS was observed in patients with LVEF <50% at baseline (n = 39): 41.4 ± 9.2% versus 45.6 ± 9.9%, and 12.9 ± 3.6% versus 15.5 ± 3.7%, respectively. In the subgroup with preserved EF (n = 62), LVEF and GLS remained stable at follow-up: 59.3 ± 5.5% versus 60 ± 5.5%, and 19 ± 3.9% versus 19.4 ± 3.8%, respectively. CONCLUSION: LBBAP prevents PICM in patients with preserved LVEF and improves left ventricle function in subjects with depressed LVEF. LBBAP might be the preferred pacing modality for bradyarrhythmia indications.

Between flood and drought: How cities are facing water surplus and scarcity.

Droughts and floods are weather-related hazards affecting cities in all climate zones and causing human deaths and material losses on all inhabited continents. The aim of this article is to review, analyse and discuss in detail the problems faced by urban ecosystems due to water surplus and scarcity, as well as the need of adaptation to climate change taking into account the legislation, current challenges and knowledge gaps. The literature review indicated that urban floods are much more recognised than urban droughts. Amongst floods, flash floods are currently the most challenging, which by their nature are difficult to monitor. Research and adaptation measures related to water-released hazards use cutting-edge technologies for risk assessment, decision support systems, or early warning systems, among others, but in all areas knowledge gaps for urban droughts are evident. Increasing urban retention and introducing Low Impact Development and Nature-based Solutions is a remedy for both droughts and floods in cities. There is the need to integrate flood and drought disaster risk reduction strategies and creating a holistic approach.

The V6-V1 interpeak interval: a novel criterion for the diagnosis of left bundle branch capture.

AIMS: We hypothesized that during left bundle branch (LBB) area pacing, the various possible combinations of direct capture/non-capture of the septal myocardium and the LBB result in distinct patterns of right and left ventricular activation. This could translate into different combinations of R-wave peak time (RWPT) in V1 and V6. Consequently, the V6-V1 interpeak interval could differentiate the three types of LBB area capture: non-selective (ns-)LBB, selective (s-)LBB, and left ventricular septal (LVS). METHODS AND RESULTS: Patients with unquestionable evidence of LBB capture were included. The V6-V1 interpeak interval, V6RWPT, and V1RWPT were compared between different types of LBB area capture. A total of 468 patients from two centres were screened, with 124 patients (239 electrocardiograms) included in the analysis. Loss of LVS capture resulted in an increase in V1RWPT by ≥15 ms but did not impact V6RWPT. Loss of LBB capture resulted in an increase in V6RWPT by ≥15 ms but only minimally influenced V1RWPT. Consequently, the V6-V1 interval was longest during s-LBB capture (62.3 ± 21.4 ms), intermediate during ns-LBB capture (41.3 ± 14.0 ms), and shortest during LVS capture (26.5 ± 8.6 ms). The optimal value of the V6-V1 interval value for the differentiation between ns-LBB and LVS capture was 33 ms (area under the receiver operating characteristic curve of 84.7%). A specificity of 100% for the diagnosis of LBB capture was obtained with a cut-off value of >44 ms. CONCLUSION: The V6-V1 interpeak interval is a promising novel criterion for the diagnosis of LBB area capture.

Functional Dissection of P1 Bacteriophage Holin-like Proteins Reveals the Biological Sense of P1 Lytic System Complexity.

P1 is a model temperate myovirus. It infects different Enterobacteriaceae and can develop lytically or form lysogens. Only some P1 adaptation strategies to propagate in different hosts are known. An atypical feature of P1 is the number and organization of cell lysis-associated genes. In addition to SAR-endolysin Lyz, holin LydA, and antiholin LydB, P1 encodes other predicted holins, LydC and LydD. LydD is encoded by the same operon as Lyz, LydA and LydB are encoded by an unlinked operon, and LydC is encoded by an operon preceding the lydA gene. By analyzing the phenotypes of P1 mutants in known or predicted holin genes, we show that all the products of these genes cooperate with the P1 SAR-endolysin in cell lysis and that LydD is a pinholin. The contributions of holins/pinholins to cell lysis by P1 appear to vary depending on the host of P1 and the bacterial growth conditions. The pattern of morphological transitions characteristic of SAR-endolysin-pinholin action dominates during lysis by wild-type P1, but in the case of lydC lydD mutant it changes to that characteristic of classical endolysin-pinholin action. We postulate that the complex lytic system facilitates P1 adaptation to various hosts and their growth conditions.

Novel approach to diagnosis of His bundle capture using individualized left ventricular lateral wall activation time as reference.

BACKGROUND: During nonselective His bundle (HB) pacing, it is clinically important to confirm His bundle capture versus right ventricular septal (RVS) capture. The present study aimed to validate the hypothesis that during HB capture, left ventricular lateral wall activation time, approximated by the V6 R-wave peak time (V6 RWPT), will not be longer than the corresponding activation time during native conduction. METHODS: Consecutive patients with permanent HB pacing were recruited; cases with abnormal His-ventricle interval or left bundle branch block were excluded. Two corresponding intervals were compared: stimulus-V6 RWPT and native HB potential-V6 RWPT. The difference between these two intervals (delta V6 RWPT), which was diagnostic of lack of HB capture, was identified using receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 723 electrocardiograms (ECGs) (219 with native rhythm, 172 with selective HB, 215 with nonselective HB, and 117 with RVS capture) were obtained from 219 patients. The native HB-V6 RWPT, nonselective-, and selective-HB paced V6 RWPT were nearly equal, while RVS V6 RWPT was 32.0 (±9.5) ms longer. The ROC curve analysis indicated delta V6 RWPT > 12 ms as diagnostic of lack of HB capture (specificity of 99.1% and sensitivity of 100%). A blinded observer correctly diagnosed 96.7% (321/332) of ECGs using this criterion. CONCLUSIONS: We validated a novel criterion for HB capture that is based on the physiological left ventricular activation time as an individualized reference. HB capture can be diagnosed when paced V6 RWPT does not exceed the value obtained during native conduction by more than 12 ms, while longer paced V6 RWPT indicates RVS capture.

Nonselective versus selective His bundle pacing: An acute intrapatient speckle-tracking strain echocardiographic study.

INTRODUCTION: We aimed to compare the acute differences in left ventricular (LV) function and mechanical synchrony during nonselective His bundle pacing (ns-HBP) versus selective His bundle pacing (s-HBP) using strain echocardiography. METHODS AND RESULTS: Consecutive patients with permanent His bundle pacing, in whom it was possible to obtain both s-HBP and ns-HBP, were studied in two centers. In each patient, echocardiography was performed sequentially during s-HBP and ns-HBP. Speckle-tracking echocardiography parameters were analyzed: Global longitudinal strain (GLS), the time delay between peak systolic strain in the basal septal and basal lateral segments (BS-BL delay), peak strain dispersion (PSD) and strain delay index. Right ventricle function was assessed using tricuspid annular plane systolic excursion (TAPSE) and tissue Doppler velocity of the lateral tricuspid annulus (S'). A total of 69 patients (age: 75.6 ± 10.5 years; males: 75%) were enrolled. There were no differences in LV ejection fraction and GLS between s-HBP and ns-HBP modes: 59% versus 60%, and -15.6% versus -15.7%, respectively; as well as no difference in BS-BL delay and strain delay index. The PSD value was higher in the ns-HBP group than in the s-HBP group with the most pronounced difference in the basal LV segments. No differences in right ventricular function parameters (TAPSE and S') were found. CONCLUSION: The ns-HBP and s-HBP modes seem comparable regarding ventricular function. The dyssynchrony parameters were significantly higher during ns-HBP, however, the difference seems modest and clarification of its impact on LV function requires a larger long-term study.

Programmed deep septal stimulation: A novel maneuver for the diagnosis of left bundle branch capture during permanent pacing.

INTRODUCTION: Permanent deep septal stimulation with capture of the left bundle branch (LBB) enables maintenance/restoration of the physiological activation of the left ventricle. However, it is almost always accompanied by the simultaneous engagement of the local septal myocardium, resulting in a fused (nonselective) QRS complex, therefore, confirmation of LBB capture remains difficult. METHODS: We hypothesized that programmed extrastimulus technique can differentiate nonselective LBB capture from myocardial-only capture as the effective refractory period (ERP) of the myocardium is different from the ERP of the LBB. Consecutive patients undergoing pacemaker implantation underwent programmed stimulation delivered from the lead implanted in a deep septal position. Responses to programmed stimulation were categorized on the basis of sudden change in the QRS morphology of the extrastimuli, observed when ERP of LBB or myocardium was encroached upon, as: "myocardial," "selective LBB," or nondiagnostic (unequivocal change of QRS morphology). RESULTS: Programmed deep septal stimulation was performed 269 times in 143 patients; in every patient with the use of a basic drive train of 600 milliseconds and in 126 patients also during intrinsic rhythm. The average septal-myocardial refractory period was shorter than the LBB refractory period: 263.0 ± 34.4 vs 318.0 ± 37.4 milliseconds. Responses diagnostic for LBB capture ("myocardial" or "selective LBB") were observed in 114 (79.7%) of patients. CONCLUSIONS: A novel maneuver for the confirmation of LBB capture during deep septal stimulation was developed and found to enable definitive diagnosis by visualization of both components of the paced QRS complex: selective paced LBB QRS and myocardial-only paced QRS.

Deep septal deployment of a thin, lumenless pacing lead: a translational cadaver simulation study.

AIMS: The recently introduced technique of direct transseptal pacing of the left bundle branch is poorly characterized with many questions with regard to the optimal implantation strategy and safety concerns largely left unanswered. We developed a cadaver model for deep septal lead deployment in order to investigate the depth of penetration in relation to lead behaviour, lead tip position, and the number of rotations. METHODS AND RESULTS: Five fresh human hearts and five lumenless, 4.1-Fr pacing leads were used for deep septal deployment simulations. The leads were positioned with the use of a dedicated delivery sheath and screwed into the interventricular septum at several sites progressively more distal from the atrioventricular ring with a predetermined number of lead rotations. During each lead deployment, the depth of tip penetration was measured and the lead behaviour was noted. Four distinct lead behaviours were observed: (i) helix only penetration, no matter how many rotations were performed, due to the 'endocardial entanglement effect' (43.1% cases) or (ii) 'endocardial barrier effect' (19.6% cases), (iii) shallow/moderate penetration, with ensuing 'drill effect' when more rotations were added (9.8% cases), and (iv) deep progressive penetration with each additional rotation, occurring when the 'screwdriver effect' was present (27.4% cases, including three septal perforations). These different lead behaviours seemed to be determined by the lead position-mainly the strength of the initial endocardial layer-and the number of fully transmitted rotations. CONCLUSION: New insights into deep septal lead deployment technique were gained with regard to safe and successful implantation.

Electrocardiographic characterization of non-selective His-bundle pacing: validation of novel diagnostic criteria.

AIMS: Permanent His-bundle (HB) pacing is usually accompanied by simultaneous capture of the adjacent right ventricular (RV) myocardium-this is described as a non-selective (ns)-HB pacing. It is of clinical importance to confirm HB capture using standard electrocardiogram (ECG). Our aim was to identify ECG criteria for loss of HB capture during ns-HB pacing. METHODS AND RESULTS: Patients with permanent HB pacing were recruited. Electrocardiograms during ns-HB pacing and loss of HB capture (RV-only capture) were obtained. Electrocardiogram criteria for loss/presence of HB capture were identified. In the validation phase, these criteria and the 'HB ECG algorithm' were tested using a separate, sizable set of ECGs. A total of 353 ECG (226 ns-HB and 128 RV-only) were obtained from 226 patients with permanent HB pacing devices. QRS notch/slur in left ventricular leads and R-wave peak time (RWPT) in lead V6 were identified as the best features for differentiation. The 'HB ECG algorithm' based on these features correctly classified 87.1% of cases with sensitivity and specificity of 93.2% and 83.9%, respectively. The criteria for definitive diagnosis of ns-HB capture (no QRS slur/notch in Leads I, V1, V4-V6, and the V6 RWPT ≤ 100 ms) presented 100% specificity. CONCLUSION: A novel ECG algorithm for the diagnosis of loss of HB capture and criteria for definitive confirmation of HB capture were formulated and validated. The algorithm might be useful during follow-up and the criteria for definitive confirmation of ns-HB capture offer a simple and reliable ancillary procedural endpoint during HB device implantation.

His-bundle pacing as a standard approach in patients with permanent atrial fibrillation and bradycardia.

BACKGROUND: His-bundle (HB) pacing is the most physiological method of ventricular pacing. However, it is also considered a demanding procedure with a low success rate and has suboptimal pacing parameters. There is a scarcity of data concerning HB pacing as a standard approach in patients with symptomatic bradycardia. Our goal was to compare acute and chronic results of two approaches to pacing in patients with permanent atrial fibrillation, narrow QRS complexes, and symptomatic bradycardia: right ventricular myocardial pacing versus HB pacing. METHODS: Consecutive patients who received HB pacemakers were compared with historical controls-i.e., consecutive patients with classic VVI pacemaker implantations, performed by the same operator before 2014 (commencement of routine HB implantations). Acute and long-term capture threshold, sensing, battery current drain, as well as procedure and fluoroscopy duration, complications, and success rate were compared. RESULTS: One hundred and twenty-five patients were analyzed (including 65 patients with HB pacing): age 73.0 ± 10.5 years, left ventricular ejection fraction of 48.2 ± 13.5%. HB pacing was inferior to right ventricular myocardial pacing in terms of higher threshold, lower sensing amplitude, higher current drain, lower success rate, longer procedure, and fluoroscopy times. However, despite this, HB procedure and fluoroscopy times of 64.4 ± 30.0 and 11.0 ± 10.7 minutes, respectively, long-term successful HB pacing in 87.9% of patients, a chronic threshold of 1.5 ± 1.1 V, chronic sensing of 3.6 ± 2.5 mV, and chronic current drain per pulse of 3.4 ± 4.4 µAh seem acceptable. CONCLUSIONS: HB pacing can be used as an alternative standard method of pacing in atrial fibrillation patients.

Restoration of a shady urban pond - The pros and cons.

The Bzura-7 pond (Lódz, Poland) is a typical shallow and shady urban reservoir situated on the Bzura River that is exposed to pollutants introduced mainly by internal loads and the supply from the catchment. In 2010-2012, the following characteristics were observed in the pond: a high allochthonous input of organic matter, high concentration of ammonium, low concentration of dissolved oxygen and low diversity of zooplankton, dominated mainly by Daphnia spp. From January to June 2013, restoration measures were performed, including sediment removal, increasing light access to the pond and construction of a sequential sedimentation-biofiltration system (SSBS). The aim of the present study was to investigate how the water quality in the Bzura-7 pond was affected by the restoration process, which included reducing pollutant inflows and enhancing habitat potential, thus increasing the diversity of this ecosystem. Restoration efforts improved the chemical and physical parameters of the water. The oxygen concentration increased, and the concentrations of TN and ammonium significantly decreased. Despite the increase in pond lighting, the growth of cyanobacteria was limited. However, we observed increased abundance of green algae and diatoms but less than adequate changes in the zooplankton community structures. Although we observed a significant increase in the zooplankton species richness after restoration, this increase was related to the small-bodied groups of zooplankton, rotifers and bosminiids, characteristic of eutrophic ecosystems. In addition, a planktivorous fish - sunbleak (Leucaspius delineatus) - was identified as an unintended side effect of the restoration effort. Further conservation efforts in the Bzura-7 pond and monitoring of results are still needed.

Blood pressure changes in patients with chronic heart failure undergoing slow breathing training.

BACKGROUND: Slow breathing training (SBT) has been proposed as a new non-pharmacological treatment able to induce favorable effects in patients with chronic heart failure (CHF). However, no information is available regarding its effects on orthostatic blood pressure (BP) changes in these patients, an issue of practical relevance given the reported BP-lowering effect of SBT. The aim of this study is to evaluate the influence of SBT on BP and whether SBT induces orthostatic hypotension (OH) or changes in quality of life (QoL) in CHF patients. METHODS: The analysis was performed as part of an ongoing crossover open trial aimed at assessing the clinical effectiveness of SBT in treated patients with CHF. The patients underwent 10-12 weeks of SBT with the RESPeRATE device and 10-12 week follow-up under usual care. Patients were randomly divided into two groups: group I began with SBT, followed by usual care; group II began with usual care, followed by SBT. Patients undergoing SBT were asked to perform each day two separate 15 min sessions of device-guided SBT at a breathing frequency of 6 breaths/min. In all patients, before the enrollment and after each study phase, clinical data collection and BP measurements in sitting, supine and standing position were performed. OH was defined as a decrease of ≥ 20 mmHg in systolic blood pressure (SBP) or ≥ 10 mmHg in diastolic blood pressure (DBP) within 3 min of standing. QoL was assessed three times at the beginning, and after each phase of the study by the Minnesota Living with Heart Failure (MLHF) questionnaire. RESULTS: Forty patients (two equal groups) completed the study, with the following baseline characteristics: 32 males/eight females, age 63.3 ± 13.4 years, 25 with ischemic CHF, 37 in New York Heart Association class II and three in class III, left ventricular ejection fraction 30.8 ± 6.7%, mean BP 138.7 ± 16.5/83.1 ± 11.5 mmHg, 23 with arterial hypertension and four with a history of stroke. There were no significant differences between the groups in clinical characteristics, SBP and DBP at rest, while seated and before and after standing up. OH prevalence was low and did not change during the study (10% vs 10%). No significant difference in average SBP and DBP changes secondary to body position were found when comparing the two study phases. Decrease in MLHF score was observed in group I during SBT (p = 0.002), but not in group II. CONCLUSIONS: Our data indicate that SBT is safe, does not affect the prevalence of OH in CHF patients and shows a non-significant tendency to improve QoL. These results should be confirmed in a larger sample of patients to support the safety of SBT and its possible benefits as a novel component of cardiorespiratory rehabilitation programs in CHF.

Leaching of PCBs and Nutrients from Soil Fertilized with Municipal Sewage Sludge.

Although sewage sludge is a rich source of nutrients for arable farming and soil improvement, it can also be a source of pollutants. The effects of the land application of sludge on the PCB and nutrient content of leachate were investigated using cylindrical 650 mm length columns filled with poor quality soil. Treatments included no fertilization (control), fertilization using a 62.5 t/ha dose (O50) of sewage sludge from the largest Polish Wastewater Treatment Plant, in Lodz, and a 62.5 t/ha dose of sewage sludge mixed with CaO (O50Ca). The leaching of sludge-borne PCBs and nutrients was simulated by the application of distilled water in a quantity reflecting the annual rainfall of 562.5 mm. The obtained results demonstrate that application of sewage sludge and water simulated leaching of the most mobile chemical compounds, nitrate for example, whereas the addition of CaO decreased the average PCB and phosphorus concentrations in comparison to the control and O50 samples.

Should abdominal CT scan be performed routinely prior to CRT insertion?

Introduction: Cancer appears to be a major noncardiovascular factor affecting morbidity and mortality of heart failure (HF) patients. Risk of developing cancer seems to increase over time. It is well documented that patients with cancer treated with chemiotherapy are at risk of developing HF and therefore they should be screened for HF on regular basis. There is limited data whether the opposite should be done, namely routinely screen each HF patient for cancer. Purpose: We hypothesized that in HF patients cancer might be responsible for some symptoms that are incorrectly diagnose as HF related. Material and Methods: The data from "Renal Denervation in Patients With Chronic Heart Failure and Resynchronization Therapy" study of 18 patients (22% women) aged 73.2 (±9.1 years) with HF in NYHA Class II-IV and resynchronization pacemaker implanted according to current ESC guideliness at least 6 months earlier were analyzed. Patients had symptoms of heart failure despite optimal HF therapy including pharmacotherapy and CRT. Medical history including current symptoms of HF was taken, patients' demographics and vital signs were assessed. Diagnostic tests in the study group included echocardiography, abdominal CT scan and laboratory tests. Results: Only in 5 patients CT scan did not show any abnormalities. Renal cysts were present in 5 patients, adrenal glands adenomas were observed in 3 patients and both changes were present in 1 patient. Tumors suspected of malignancy were diagnosed in 4 patients - 2 had a tumor in adrenal glands, 1 had kidney tumor and 1 had tumors both in kidney and adrenal gland. All patients with malignancy were directed for further oncological evaluation. Conclusion: Considering the complex physiology of HF, there is possibility that some HF related mechanisms might trigger cancer development and presence of cancer may aggrevate the symptoms of HF. One should consider evaluation of HF patients on optimal medical therapy, yet still symptomatic to identify some common forms of cancer.

The occurrence of heavy metals and antimicrobials in sewage sludge and their predicted risk to soil - Is there anything to fear?

The study assessed the occurrence of legally-monitored heavy metals and unmonitored antimicrobials in sludge from small, medium, large and very large municipal wastewater treatment plants (WWTPs), and the predicted environmental risk and risk of resistance selection associated with sludge administration to soil. The temporal variations of the studied compounds in sludge and associated risks to soil were determined by sampling over a year. Although the highest concentrations of heavy metals were noted in sludge from the largest WWTP, i.e. from 1.50 mg/kg (mean 1.61 mg/kg) for Cd to 2188 mg/kg (mean 1332 mg/kg) for Zn, the obtained values only reached a few percent of the legal limits. The same WWTP also demonstrated lower concentrations of antimicrobials compared to the smaller ones. The highest concentrations of antimicrobials, ranging from 24.04 µg/kg for trimethoprim to 900.24 µg/kg for tetracycline, were found in the small and medium WWTPs. However, due to lack of regulations at the national and EU levels, the results cannot be compared with legal limits. Principal Component Analysis (PCA), cluster and heatmap analysis separated samples according to WWTP size. Small WWTP demonstrated correlation with antimicrobials (tetracycline, trimethoprim, clindamycin, ciprofloxacin and ofloxacin), while the large and very large WWTP revealed correlations with heavy metals (Cu and Cr). The obtained environmental risk quotients confirmed that the heavy metals did not present a threat, measured either as individual risk quotients (RQenv), cumulative risk (RQcumulative) or risk of mixture of heavy metals (RQmix-metals). In the case of antimicrobials, only tetracycline demonstrated moderate RQenv, RQcumulative and RQmix-antimicrobials in the small WWTP sludge, with values of 0.1 to 1. Our findings highlight the importance of monitoring sewage sludge before soil application, especially from small WWTPs, to reduce the potential environmental impact of antimicrobials. They also confirm our previous data regarding the environmental risk associated with various toxic compounds, including emerging contaminants, in the sludge from small WWTPs.

Microbial response to Nature-Based Solutions in urban soils: A comprehensive analysis using Biolog® EcoPlates™.

The study presents a comprehensive examination of changes in soil microbial functional diversity (hereafter called microbial activity) following the implementation of Nature-Based Solutions (NBS) in urban areas. Utilizing the Biolog® EcoPlates™ technique, the study explored variations in microbial diversity in urban soil under NBSs implementation across timespan of two years. Significant differences in microbial activity were observed between control location and those with NBS implementations, with seasonal variations playing a crucial role. NBS positively impacted soil microbial activity especially at two locations: infiltration basin and wild flower meadow showing the most substantial increase after NBS implementation. The study links rainfall levels to microbial functional diversity, highlighting the influence of climatic conditions on soil microbiome. The research investigates also the utilization of different carbon sources by soil microorganisms, shedding light on the specificity of substrate utilization across seasons and locations. The results demonstrate that NBSs implementations lead to changes in substrate utilization patterns, emphasizing the positive influence of NBS on soil microbial communities. Likewise, biodiversity indices, such as Shannon-Weaver diversity (H'), Shannon Evenness Index (E), and substrate richness index (S), exhibit significant variations in response to NBS. Notably, NBS implementation positively impacted H' and E indexes, especially in infiltration basin and wild flower meadow, underlining the benefits of NBS for enhancing microbial diversity. The obtained results demonstrated valuable insight into the dynamic interactions between NBS implementation and soil microbial activity. The findings underscore the potential of NBS to positively influence soil microbial diversity in urban environments, contributing to urban sustainability and soil health. The study emphasizes the importance of monitoring soil microbial activity to assess the effectiveness of NBS interventions and guides sustainable urban development practices.

Transseptal Transition Patterns During Left Bundle Branch Area Lead Implantation.

BACKGROUND: Continuous deep septal pacing and signal recording during implantation of left bundle branch pacing (LBBP) lead enables to monitor beat-to-beat changes of electrocardiogram (ECG) and myocardial current of injury (COI) as the lead crosses the septum. OBJECTIVES: This study aimed to characterize patterns of continuous QRS, ST-T, and COI change for monitoring of the lead depth and instantaneous determination of the obtained capture type (LBBP vs left ventricular septal pacing [LVSP]). METHODS: The ECG and COI during lead implantation were scrutinized for sudden changes of V6 R-wave peak time, V1 initial and terminal R-wave amplitude, V3-V6 R-wave amplitude, repolarization pattern and S-wave amplitude in I, V5-V6, and COI drop. The sudden and gradual transition patterns were diagnosed depending on the presence or absence of the above beat-to-beat ECG phenomena, respectively. RESULTS: A total of 212 pacemaker recipients were analyzed; LBBP and LVSP were obtained in 77.4% and 22.6%, respectively. There were 4.7 ± 2.1 and 0.2 ± 0.6 beat-to-beat phenomena in LBBP and LVSP patients, respectively. The sudden transition pattern, recognized in 80.7%, had sensitivity and specificity for LBBP diagnosis of 98.8% and 81.2%, respectively. A sudden drop of COI (29.4 ± 8.5 mV to 12.8 ± 4.9 mV) was observed in 53.9% patients (LBBP was simultaneously obtained in 92.7%). CONCLUSIONS: Capture of left bundle branch during lead penetration is a beat-to-beat phenomenon. Two transseptal transition patterns were identified: 1) sudden, which is typical for obtaining LBBP; and 2) gradual, which is typical for obtaining LVSP. A sudden COI drop, a very observable phenomenon, also identified reaching the left subendocardial area.

Global R-wave peak time for diagnosis of left bundle branch capture.

BACKGROUND: QRS axis deviation and rS configuration in V6 affect the ability of V6 R-wave peak time (RWPT) criterion to discriminate capture type during left bundle branch area pacing (LBBAP). OBJECTIVE: We hypothesized that combining RWPTs from lateral leads: I, aVL, V5, and V6 may better reflect left ventricular activation time and that such a global RWPT may be insensitive to changes in QRS configuration. METHODS: The analysis included 519 ECGs with non-selective left bundle branch pacing (nsLBBP) and 176 ECGs with left ventricular septal pacing (LVSP). Optimal RWPT cutoffs and area under the receiver operating curve (AUC) were determined for each lead and combinations of leads, to find the best RWPT criterion for discriminating nsLBBP from LVSP. Values were reported separately for healthy/diseased left conduction system groups. RESULTS: The highest AUC of 97.1/89.2% was obtained for the global RWPT, which combined leads I and V6. The AUC for single lead RWPT, was highest for lead I, followed by V6, V5, and aVL with AUC of 95.1/87.4%, 93.6/87.1%, 93.0/86.5%, and 84.8/74.6%, respectively. The global RWPT criterion was not affected by variations in QRS configuration, as V6 and I RWPTs often showed opposite responses to changes in axis. In contrast, all single-lead RWPT criteria were sensitive to axis deviation and QRS configuration. Diagnostically optimal RWPT cutoffs for global RWPT and lead I RWPT were 162.5/187.5 ms, and 81.5/90.5 ms, respectively. CONCLUSION: The global RWPT criterion allows a more accurate diagnosis of LBBAP capture type independent of QRS configuration and axis.

Left bundle branch area pacing improves right ventricular function and synchrony.

BACKGROUND: The impact of left bundle branch area pacing (LBBAP) on right ventricular (RV) function and tricuspid regurgitation (TR) remains unclear. OBJECTIVE: We aimed to assess the long-term effects of LBBAP on RV performance and on TR. METHODS: RV function was evaluated using RV free wall strain, tricuspid annular plane systolic excursion, fractional area changing, and systolic velocity of the lateral tricuspid annulus. The presence of reverse septal flash (RSF) and basal bulge (BB) was used to assess RV motion pattern. The distance between the lead entry site on the interventricular septum and the septal leaflet of the tricuspid annulus (lead-TV distance) was measured. RESULTS: The analysis included 122 subjects [62 men (50.8%); mean age 76.5 ± 11.4 years] with a median follow-up of 21 months (18-24.5 months). During follow-up, RV free wall strain improved significantly (15.2 ± 5.8 vs 16.4 ± 5.5; P < .001) while tricuspid annular plane systolic excursion, systolic, and fractional area changing remained unchanged. Left ventricular ejection fraction was an independent predictor of improved RV function (B = 3.51; 95% confidence interval 1.39-8.9; P = .01). With LBBAP, RSF disappeared in 22 of 23 patients (96%) and BB in 15 of 22 patients (68%) in whom RSF and BB were present at baseline, respectively. RV function improvement was significantly higher when RSF was present at baseline (14 patients vs 11 patients; P = .02). At follow-up, no significant deterioration in TR occurred for the overall group. However, a lead-TV distance of <24.5 mm was associated with TR progression. CONCLUSION: LBBAP has a favorable impact on RV function. A basal LBBAP position is associated with worsening TR.

Strength-duration curves for left bundle branch area pacing.

BACKGROUND: Despite growing clinical use of left bundle branch pacing (LBBP), data regarding the fundamentals of this pacing modality, including chronaxie and rheobase, are scarce. OBJECTIVE: The purpose of this study was to calculate strength-duration curves with chronaxie and rheobase values for LBBP and left ventricular septal pacing (LVSP), and to analyze battery current drain and presence of selective LBBP at very short pulse duration (PD). METHODS: A group of 141 patients with permanent LBBP were studied. LBBP and LVSP capture thresholds were assessed at 6 different PDs to calculate the strength-duration curves. Battery current drain at these PDs and presence of selective LBBP were determined. For comparison of strength-duration curves between His-bundle pacing (HBP) and LBBP, source data from our previous work based on 127 patients with HBP were obtained. RESULTS: The chronaxies for LBBP and LVSP were very similar (0.38 vs 0.39 ms), and the rheobases were identical (0.27 V). The chronaxie for LBBP was lower than for HBP (0.38 vs 0.53 ms; P <.001), whereas rheobases were similar (0.27 vs 0.26 V). A narrow zone of selective capture was present in 19% and 41% of patients at PD of 0.06 and 0.03 ms, respectively. When pacing with the safety margin of +1 V, the lowest battery current drain was achieved with PD of 0.2 ms. CONCLUSION: The obtained strength-duration curves for LBBP and LVSP provide insights to optimal programming of left bundle branch area pacing devices with regard to PD, voltage amplitude, battery longevity, and selective capture.