Bundle Area Research Articles

PO-673-03 ANODAL CAPTURE DURING LEFT BUNDLE AREA PACING OVERCOMES DELAYED RIGHT VENTRICULAR ACTIVATION BUT DOES NOT OFFER ANY HAEMODYNAMIC ADVANTAGE

The use of Left bundle area pacing is rapidly growing for both bradycardia and CRT indications. It offers physiological activation of the left ventricle, but right ventricular activation may be delayed. It is often possible to shorten QRS duration and eliminate the R wave in V1 by adjusting pacing output and/or configuration. It is not clear whether the reduction in QRS occurs as a result of bi-bundle capture or due to RV septal capture and it is not known whether programming this configuration offers an advantage in cardiac function. To assess the mechanism of QRS reduction and R prime elimination during left bundle area pacing (ECGi mapping) and whether this confers any haemodynamic benefit. Patients implanted with a LBAP lead were recruited if they exhibited R prime in lead V1 response to pacing and R prime could be eliminated by changing pacing output or configuration (e.g. switch from unipolar to bipolar pacing). We used ECGi mapping to determine ventricular activation (septal myocardial capture or bibundle capture) and a high precision haemodynamic protocol to measure systolic blood pressure change for each capture type. 15 patients were recruited (11 male), mean age 68 ± 11 years. Bradycardia was the pacing indication in 4 (27%) patients, heart failure in 11 (73%).ECGi mapping suggested that the mechanism of shortening of QRS duration was due to RV septal myocardial capture, rather than bi-bundle capture in all of our patients.Left bundle plus right septal capture was associated with significantly narrower QRS duration compared to left bundle only capture (-11.7ms, 95% CI: -15.7 to -7.6 ms, P<0.0001). However, this response required higher pacing outputs (mean threshold 3.28 V ± 2.16 at 0.4ms vs 0.69 V ± 0.25 at 0.4ms, p=0.0004) (Figure 1).Despite the narrower QRS duration, there was no significant difference in systolic blood pressure between the two capture types (-0.96 mm Hg; 95% CI: -3.3 to 1.4 mm Hg; P>0.05). (Figure 1). During left bundle branch pacing it is often possible to deliver earlier right ventricular activation achieved by right septal capture. However, this requires significantly higher pacing outputs without any haemodynamic advantage. When programming these devices, the lowest threshold that achieves left bundle capture is acceptable.

PO-673-06 CARDIAC RESYNCHRONIZATION WITH LEFT BUNDLE AREA PACING COMPARED TO HIS BUNDLE AND BIVENTRICULAR PACING; AN ACUTE ELECTRICAL AND HAEMODYNAMIC WITHIN PATIENT COMPARISON

His bundle pacing (HBP) is an effective form of cardiac resynchronization therapy with the drawback of high thresholds and relatively high rates of lead replacement. Left bundle area pacing (LBP) avoids these drawbacks. However, it is not known if stimulating the left bundle alone and the consequent delay in right ventricular activation makes it a less effective form of cardiac resynchronization. In order to address this, we conducted a within patient comparison of acute electrical and haemodynamic response to HBP, LBP and biventricular pacing (BVP).

Characterization of Source–Sink Traits and Carbon Translocation in Maize Hybrids under High Plant Density

Both compact planting and selecting superior maize (Zea mays L.) hybrids can greatly optimize the source–sink relationship and enhance maize productivity. However, the underlying physiological mechanism for regulating carbon (C) assimilate transport and influencing grain yield between maize cultivars has remained unclear under contrasting plant densities. A two-year field experiment was conducted to investigate grain yield, vascular bundle character, grain filling, C allocation in grains and other tissues, and hormone level and enzyme activity in grains under 60,000 (ND) and 90,000 plants ha−1 (HD) densities using Xianyu 335 (XY335) and Zhengdan958 (ZD958) hybrids. Compared to the ZD958, XY335 increased grain yield, kernel number per plant (KNP), and sink capacity by 11.4%, 15.7%, and 7.4%, respectively. Moreover, XY335 performed higher net photosynthetic rate and sucrose synthase activities in grains than those in ZD958, and higher levels of sucrose phosphate synthase and soluble acid invertase activity were mainly exhibited in the middle of the grain filling stage, which contributed to increasing the proportion of grain in total dry matter, grain C content and leaf C transport efficiency by 4.3%, 12.2%, and 52.9%, respectively, under HD conditions. Additionally, a greater area and number of small vascular bundle in ear of XY335 resulted in 21.3% higher matter transport efficiency and 4.8% higher maximum grain filling rate than ZD958 under HD conditions. In addition, grains of XY335 exhibited generally higher levels of indole acetic acid (IAA) and abscisic acid (ABA), as well as ABA/GA3 ratio after maize pollination relative to those from ZD958, conducive to regulating C translocation from leaves to grains. Overall, our study illustrates that stronger source activity, sink characteristics, and matter transport channels for maize hybrids are significant for C assimilate transport to grain for achieving high grain yield under higher plant density.

Analysis and Prediction of Flow-Induced Vibration of Convection Pipe for 200 t/h D Type Gas Boiler

This paper is aimed at the analysis and prediction of the fluid-induced vibration phenomenon in the convection tube bundle area caused by Karman vortex street shedding in the background of a 200 t/h large-capacity D-type gas boiler. Based on the numerical simulation of flue heat state flow field and fast Fourier transform, the lift coefficient curve of different monitoring areas and the corresponding Karman vortex street shedding frequency are obtained. The accuracy of the analysis model is validated by comparing Karman vortex shedding frequency with acoustic equipment standing wave frequency. In order to meet the design requirements of the 200 t/h D-type gas boiler for reliable and stable operation, the vibration characteristics and variation rules of a convection tube bundle in a D-type boiler under different working conditions are predicted.

Effect of Aging on the Vocal Muscle

Sarcopenia is a common and natural condition in the elderly, and leads to loss of muscle mass and function. In the presbylarynx there is atrophy of the vocal folds, however the degree of vocal muscle atrophy is poorly studied and the results are contradictory. The aim of this study was to evaluate the effect of aging on the vocal muscle (thyroarytenoid muscle). Thirteen larynxes removed during necropsy from 13 cadavers were included into two age groups: Control group - G1 (n5), between 25 and 40 years; Elderly Group - GI (n-8), aged 70 years or older. The vocal folds were dissected and prepared for scanning electron microscopy, ensuring a cross-section in the musculature area to allow measurements of muscle fiber parameters. Images were analyzed and photographed at different magnifications. Through the ImageJ software, ten distinct fields of each part were selected. Parameters studied: area, perimeters and diagonals of the thyroarytenoid muscle bundles of both groups. The cross-sectional areas, perimeters and diagonals of the muscle fibers of the thyroarytenoid muscle of the elderly group were significantly smaller than those of the control group. We demonstrated that the vocal muscle is affected in the presbylarynx, with a reduction of its muscle fibers, corresponding to muscle atrophy. However, these findings may not be directly related to vocal symptoms because the patient may develop muscle compensatory mechanisms capable of reducing glottic insufficiency.

Transventricular Left Bundle Branch Pacing

Background. Implementation of conduction system permanent pacing methods in patients with cardiac bradyarrhythmias allows to maintain the physiological sequence of excitation and contraction of the ventricles and to avoid the development of heart failure due to electrical and mechanical dyssynchrony in patients with high rates of ventricular pacing.&#x0D; Case description. A 61-year-old female patient was examined and treated at the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine from January 25 to January 27, 2022 at the department of surgical treatment of complex cardiac arrhythmias with a diagnosis of proximal complete atrioventricular block. A two-chamber pacemaker (Vitatron Q50A2) with a ventricular lead to stimulate the His bundle region (Medtronic 3830, 69 cm) was implanted to the patient with a special delivery system (C315HIS). At an X-ray operating room, 12 ECG leads from the electrophysiological station LabSystem Pro (Bard, USA) were connected to the patient to analyze the criteria for capturing the conduction system on stimulation during ventricular lead placement, and a diagnostic quadripolar electrode was inserted into the right ventricle to record the potential of the His bundle as an X-ray reference point. During placement of the ventricular lead in the area of the His bundle due to high pacing thresholds the decision was made to implement an alternative method of conduction system pacing – left bundle branch pacing through the interventricular septum. After gradual passage of the electrode through the septum, capture of the conduction system of the heart was achieved, although no clear potential of the left bundle was registered. The interval from stimulus to peak R wave in lead V6 was 68 ms, and the interval from stimulus to peak R wave in lead V1 was 110 ms. The difference between intervals was 42 ms, which indicated the criteria of nonselective capture of the left bundle branch, with stimulation thresholds below 1 V at a pulse length of 0.5 ms. In the postoperative period, the patient was evaluated for global longitudinal deformity of the left ventricle on constant ventricular stimulation, which was carried out according to standard methods using speckle-tracking echocardiography; no signs of dyssynchrony were found. Also, the location of the endocardial electrode in the middle segments of the interventricular septum on the right ventricular side was visualized and confirmed by performing B-mode transthoracic echocardiography with subcostal access.&#x0D; Conclusions. Left bundle branch pacing, like His bundle pacing, maintains electrical and mechanical synchrony of the left ventricle at lower pacing thresholds, greater amplitude of the sensitivity signal and lower risks of lead dislocation.

Electrocardiographic optimization of PR interval in Left Bundle Area Pacing

Electrocardiographic optimization of PR interval in Left Bundle Area Pacing

Differential Expression of MSTN Isoforms in Muscle between Broiler and Layer Chickens.

Simple SummaryIncreasing the growth rate of food animals with a concomitant increase in muscle yield is a primary goal of animal producers. The identification of factors and a better understanding of the underlying mechanisms of these factors for muscle growth are important if we are to improve meat production in domestic animals. In avian species, MSTN-A has anti-myogenic activities and MSTN-B functions as a pro-myogenic factor. In this study, the expression of the Mstn isoforms and the sizes of myofibers and muscle bundles during development were analyzed in broiler and layer chicken breeds. Although the expression levels of total Mstn were not different between the two breeds, the ratios of Mstn-B to -A were significantly higher in the broilers with muscle hypertrophy and hyperplasia compared to the layers. Further characterizations of the muscle in broilers revealed a greater bundle area but similar fiber number per bundle compared to the layers. Our study demonstrated higher ratios of Mstn-B/-A expression in the muscles of broiler chickens, suggesting that the development of strategies to enhance the expression of Mstn-B will lead to increased muscle growth and poultry production.Myostatin (Mstn)-A, the main isoform among Mstn splicing variants, functions as a negative regulator, whereas Mstn-B functions as a positive regulator in muscle development. Because broiler chickens are a fast-growing breed raised for meat production and layer chickens are a slow-growing breed raised for egg production, differences in the expression of Mstn isoforms between the two distinct breeds were analyzed in this study. There was no difference in the expression levels of total Mstn (Mstn-A and -B forms) during embryonic development and at D33 between the two breeds. Interestingly, the ratios of Mstn-B to -A were significantly higher in the broiler compared to the layer at most ages. In pectoralis major muscle (PM) tissue, the cross-sectional area (CSA) of muscle fiber was significantly greater in the broiler. The broiler also showed greater bundle CSA and a similar fiber number per bundle compared to the layer at D5 and D33. These data suggest that the greater bundle CSA with myofiber hypertrophy in the broilers is associated with greater muscle growth. The relationship between the expression of Mstn isoforms and growth rate can be used as a potential genetic marker for the selection of higher muscle growth in chickens.

Structural and functional responses in widespread distribution of some dominant grasses along climatic elevation gradients

The adaptability potential of plants enables them to colonize diverse habitats along elevation gradients. Studying these adaptive traits and linking them to environmental attributes provide useful information to understand limitations imposed by elevation gradients on distribution of plant species. To meet these objectives, six most dominant perennial grass species with broad distributional ranges along an elevation gradient from 300–1400 m a.s.l in northern Punjab (Pakistan) were selected for the present study. Dominance of different grass species were linked to proportion of parenchyma, sclerification of aerial plant parts, size of vascular tissue, leaf thickness, and size and density of trichomes. Chrysopogon serrulatus dominated all elevations except the highest one, which was directly linked to increased root area and high proportion of storage parenchyma, vascular region, large metaxylem vessels, increased sclerification in aerial parts, and size and density of trichomes. Cymbopogon jwarancusa dominated lower and middle elevations (300–1000 m) and exhibited increased sclerification in stem and leaves, higher vascular bundle area, and, increased leaf sheath thickness. Lognormal distribution exhibited a non-linear response for eco-morphological and physiological characteristics with decreasing pattern along increase in elevation. Physiological traits responded negatively in response to climatic variables. Root anatomical traits exhibited nonlinear response at lower elevation, while stem traits responded positively at medium elevational gradients (700–1000 m). Leaf sheath showed positive response with elevation and temperature. In conclusion, morpho-physiological and anatomical modifications were specific to grasses studied, which contributed differently towards growth and survival along elevation gradient.

Enhancement of Lodging Resistance and Lignin Content by Application of Organic Carbon and Silicon Fertilization in Brassica napus L.

This study was aimed to investigate the effects of organic carbon and silicon fertilizers on the lodging resistance, yield, and economic performance of rapeseed. Two cultivars, namely Jayou (lodging-resistant) and Chuannongyou (lodging-susceptible), were selected to evaluate the effects of various fertilizer treatments on rapeseed culm morphology, lignin accumulation, and their relationships with their lodging resistance indices. The results showed that both organic carbon and silicon fertilizer applications increased the plant height, basal stem diameter, internode plumpness, and bending strength of rapeseed in both the studied years. The bending strength was significantly and positively correlated with the lodging resistance index and lignin content. It was found that both organic carbon and silicon fertilizers had improved the activities of lignin biosynthesis enzymes (phenylalanine ammonia-lyase, 4-coumarate:CoA ligase, cinnamyl alcohol dehydrogenase, and peroxiredoxins) and their related genes to increase lignin accumulation in the culm, which ultimately improved the lodging resistance. At the same time, the thickness of the stem cortex, vascular bundle area, and xylem area was increased, and the stem strength was improved. The effect of silicon fertilizer was better than that of organic carbon fertilizer, but there was no significant difference with the mixed application of silicon fertilizer and organic carbon fertilizer. Similarly, silicon fertilizer increased the number of pods, significantly increased the yield, and improved the economic benefit, while organic carbon fertilizer had no significant effect on the yield. Therefore, we believe that organic carbon and silicon fertilizer can improve the lodging resistance of rape stems by improving the lignin accumulation and the mechanical tissue structure. Still, the effect of silicon fertilizer is the best. Considering the economic benefits, adding silicon fertilizer can obtain more net income than the mixed application of silicon fertilizer and organic carbon fertilizer.

Effect of fertilizing with different levels of phosphorous and zinc on the botanical characteristics of table beet (Beta vulgaris L.)

The interaction of phosphorus (P) and zinc (Zn) is a crucial factor affecting crop yield in agricultural production called a P-induced Zn deficiency. The application of Zn and P together reduces deficiencies and increases plant growth by more than the sum of the increases from Zn and P alone. This experiment was carried out during two seasons, in consecutive years, to study the effect of P and Zn levels on the physical, physiological and anatomical response in table beet plants. Treatment one was as control; the second treatment was 35 P units with 5, 10, and 20 Zn units; the third treatment was 40 P units with 5, 10, and 20 Zn units; and the fourth treatment was 45 P units with 5, 10, and 20 Zn units. The data showed that the number of leaves and the root diameters were high with the addition of 40 P units and 10 Zn units, and the roots fresh and dry weights were high under 40 P units and 10 Zn units in both seasons. The contents of TSS, AA, TS, ACY, N, P, and K were significantly increased by the use of 40 and 45 P units combined with 5 and 10 Zn units. The anatomical alterations in both leaf blade, epidermal layers, midrib zone, vessel diameter, vascular bundle area, palisade, and spongy tissues were studied. The results recommend that fertilizing table beet plants with 40 P units and 10 Zn units is suitable.

Structural responses of differentially adapted Cenchrus setigerus Vahl ecotypes to water deficit

Two ecotypes of Cenchrus setigerus Vahl (birdwood grass) were collected from dry mountains surrounding hyper-saline Kalar Kahar Lake and Gatwala artificial forest plantation. The ramets of the two ecotypes were established in pots for 15 days and then subjected to 100% FC (control) or 75% and 50% FC (field capacity) levels. Growth attributes such as plant height, tillers per plant, leaves per plant, shoot fresh and dry weights were severely affected while root length was the only attribute that increased in both ecotypes under moisture stress. Root anatomical attributes like cortical and pith parenchyma, and vascular region thickness increased in both ecotypes under water stress. Root radius increased in the Faisalabad ecotype at 75% FC, while increased in Salt Range ecotype only at 50% FC. Stem cellular region, sclerenchymatous cell area, vascular bundle area and metaxylem area increased significantly under moderate and severe water deficit only in the Faisalabad ecotype. The Salt Range ecotype exhibited intensive sclerification and large vascular tissue at 50% FC. Leaf anatomical attributes like epidermal cell area, bundle sheath thickness, sclerenchyma thickness and its cell area, and, vascular bundles area significantly increased in the Salt Range ecotype with increasing water deficit. The Faisalabad ecotype showed significant increase in vascular bundle area, metaxylem area and adaxial stomatal area. These findings indicated that both C. setigerus ecotypes mainly relied on water conservation and survival rather than maintaining growth and biomass production. The anatomical modifications at root, stem and leaf levels ensured survival of C. setigerus ecotypes in extreme arid conditions. • Growth attributes were severely affected while root length increased under stress • Root radius increased in the Faisalabad ecotype at 75% FC, while at 50% FC in Salt Range ecotype • Stem area, sclerification and vascular bundle area increased only in Faisalabad ecotype • The Salt Range ecotype exhibited intensive sclerification in leaves and large vascular tissue at 50% FC • The Faisalabad ecotype showed an increase in vascular bundle area, metaxylem area and adaxial stomatal area

Responses of leaf hydraulic traits of Schoenoplectus tabernaemontani to increasing temperature and CO2 concentrations

BackgroundAgainst the background of a changing climate, the responses of functional traits of plateau wetland plants to increasing temperatures and CO2 concentrations need to be understood. Hydraulic traits are the key for plants to maintain their ecological functions and affect their growth and survival. However, few studies have comprehensively considered the response strategies of wetland plants' hydraulic traits to environmental changes in the context of water and matter transport, loss, and retention. According to the latest IPCC prediction results, we performed experiments under increased temperature (2 °C) and CO2 levels (850 μmol/mol) in an artificial Sealed-top Chamber (STC) to investigate the responses of the hydraulic characteristics of Schoenoplectus tabernaemontani, the dominant species in plateau wetlands in China.ResultsCompared with the CK group, net photosynthetic rate, transpiration rate, stomatal length, cuticle thickness, vascular bundle length, vascular bundle width, and vascular bundle area of S. tabernaemontani in the ET group were significantly reduced, whereas stomatal density and vein density increased significantly. Compared with the CK group, the hydraulic traits of S. tabernaemontani in the EC group were reduced considerably in stomatal length and cuticle thickness but increased dramatically in stomatal density, and there were no significant differences between other parameter values and the control group. Net photosynthetic rate was significantly positively correlated with stomatal length, cuticle thickness, and vascular bundle length, and stomatal conductance was significantly positively correlated with cuticle thickness. The transpiration rate was significantly positively correlated with cuticle thickness, epidermal cell area, vascular bundle length, vascular bundle width, and vascular bundle area. Regarding the hydraulic traits, there was a significant negative correlation between stomatal density and stomatal length, or cuticle thickness, and a significant positive correlation between the latter two. The epidermal cell area was significantly positively correlated with epidermal thickness, vascular bundle length, vascular bundle width, and vascular bundle area.ConclusionsIncreased temperature and CO2 levels are not conducive to the photosynthetic activity of S. tabernaemontani. Photosynthetic rate, stomatal density and size, vein density, epidermal structure size, and vascular bundle size play an essential role in the adaptation of this species to changes in temperature and CO2 concentration. In the process of adaptation, hydraulic traits are not isolated from each other, and there is a functional association among traits. This study provide a scientific basis for the management and protection of plateau wetlands.

A left bundle branch block morphology tachycardia with fragmented potentials at the His bundle area.

A left bundle branch block morphology tachycardia with fragmented potentials at the His bundle area.

Electrospun Polycaprolactone (PCL)-Amnion Nanofibrous Membrane Promotes Nerve Repair after Neurolysis.

Peripheral nerve adhesion after neurolysis leads to nerve dysfunction, limiting nerve regeneration and functional recovery. We previously developed an electrospun polycaprolactone (PCL)-amnion nanofibrous membrane for preventing adhesion formation. In this study, we investigated the effect of protective nerve wrapping and promoting nerve regeneration in a rat sciatic nerve compression model. A total of 96 SD rats after sciatic nerve chronic compression were randomly divided into three groups: the PCL-amniotic group, in which nerves were wrapped with a PCL-amniotic membrane for treatment; the chitosan group, in which nerves were wrapped with a clinically used chitosan hydrogel; the control group, which involved neurolysis alone without treatment. Twelve weeks postoperatively, the nerve regeneration was evaluated by general and ultrastructure observation, as well as the expressions of neuronal regeneration and inflammatory reaction biomarkers. The nerve functions were assessed with gastrocnemius muscle measurement, hot-plate test, and walking track analysis. Compared with the chitosan hydrogel, the PCL-amnion nanofibrous membrane significantly reduced peripheral nerve adhesion and promoted nerve regeneration. The morphological properties of axons in the nerve wrap group were preserved. Intraneural macrophage invasion, as assessed by the number of CD68-positive cells, was less severe in the PCL-amnion group than in the other groups. Additionally, the gastrocnemius muscle weight and muscle bundle area were significantly higher in the PCL-amnion group than those in the chitosan group. The abilities of sense and movement of the rats in the PCL-amnion group were significantly improved compared to the other groups. In summary, electrospun PCL-amnion nanofibrous membranes effectively prevented post-neurolysis peripheral nerves from developing adhesion, whereas promoted nerve repair and regeneration, which make PCL-amnion nanofibrous membranes a promising biomaterial for clinical application.

Load Bearing Simulation of Knee Ligament Fiber Bundles Attachment States

In this study, we developed a knee simulation model considering the attachment area of the knee joint cruciate ligament bundles. 3D geometry extraction of the femur, tibia, anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL) from CT images of the knee joint. In addition, the stress-strain curves of ligaments were derived from uniaxial tensile tests. A finite element analysis model of the knee joint was created based on the above conditions. The state of ligament bundle attachment was reproduced by dividing the attachment area of the ACL and PCL to the femur and tibia. As a result, although the behavior of the ligament during compression remained to be an issue, similar tendencies to those of ligament desmotomy studies were obtained.

Ultrasonic Measurement of Two-Dimensional Liquid Velocity Profile Using Two-Element Transducer

The flow field or multidimensional velocity distribution of the coolant in fuel rod bundles of the reactor core in pressurized water reactors (PWRs) is an important parameter that is revealed through experimental investigations. This paper presents the two-dimensional (2D) velocity profile measurement using a two-element ultrasonic transducer with both elements acting as a transceiver. The size of the transducer is minimized for compactness, leading to a narrow sound field appropriate for applications in fuel rod bundle flow. Furthermore, the transducer’s sound pressure is evaluated via simulations and experimental measurements. In order to confirm the ability of the ultrasonic velocity profiler (UVP) with a two-element transducer, the experimental measurement is conducted in turbulent horizontal pipe flow. The 2D velocity vector profile is obtained, and then the measurement in swirling flow is conducted. The 2D velocity profile in an axial and radial plane is obtained utilizing the UVP measurement. Lastly, the ability of the UVP to derive the 2D velocity profile in the narrow area of the rod bundles is demonstrated.

Septal Scar Predicts Success of Lead Advancement to the Left Bundle Area

Septal Scar Predicts Success of Lead Advancement to the Left Bundle Area

Evaluation of retinal nerve fiber and ganglion cell layers in patients with multiple sclerosis and fibromyalgia

AbstractPurposeTo assess the differences in the retinal nerve fiber layer (RNFL) and ganglion cells (GCL) between patients with multiple sclerosis versus fibromyalgia. Likewise, to evaluate the ability of the Posterior Pole protocol from Spectralis Optical Coherence Tomography (OCT) to detect clusters with differences between these groups.MethodsWe analyzed 100 eyes of healthy subjects (CS), 100 eyes of patients with relapsing‐remitting multiple sclerosis (RR‐MS) and 55 eyes of patients with fibromyalgia (FB). The thickness of the RNFL and the GCL between these groups were evaluated in the 64 cells of the macular grid analyzed by the Posterior Pole protocol and later the thickness maps and cluster detection were reproduced thanks to the matrix analysis using Matlab (Mathworks,USA). Additionally, the RR‐MS group was compared with the different fibromyalgia phenotypes (atypical, biological and depressive).ResultsBoth pathologies present a very similar significant thinning (p &lt; 0.05) of both layers compared to healthy subjects. Compared with healthy controls, significant differences were found for the RNFL in the papillomacular bundle area and for the GCL in the macular area in RR‐MS group and fibromyalgia patients. Additionally, no significant differences were observed between patients with RR‐MS and those with fibromyalgia.ConclusionsFor the last years, the GCL has been postulated as a potential biomarker of neurodegenerative processes. Both RR‐MS and fibromyalgia present a similar thinning of the RNFL and GCL, although it is greater in patients with RR‐MS. Observed alterations are more significant in the GCL, thus suggesting that fibromyalgia might be a neurodegenerative process, with results similar to those observed in other well studied degenerative processes.

His Bundle Pacing and its Alternatives

Cardiac pacing remains the only definitive therapy for nonreversible bradycardia. The deleterious effects of long-term right ventricular (RV) apical pacing have been well recognized. Physiological pacing is to mobilize the intrinsic conduction system as much as possible or mimics a full cycle of atrioventricular activation and would provide an optimal clinical outcome and improve traditional RV apical and cardiac resynchronization therapy biventricular pacing modalities. His bundle pacing (HBP) and bundle area pacing are emerging modalities for a possible better electrophysiological performance. In this review, definition, characteristics, and evidence on the advantages or disadvantages of HBP and its alternatives are discussed.