Many clinical, neuroimaging, neuropathological, epidemiological, and genetic data suggest a relationship between essential tremor (ET) and Parkinson's disease (PD). Several hypothesis-based gene association studies attempted to find a genetic association between these diseases. Recent case-control association studies in Chinese and Spanish populations showed a marginal association between the rs1922452 and rs951818 single nucleotide variants (SNVs) and the risk of PD.
View Article and Find Full Text PDFThose using the mouse for the purposes of electrophysiological research presume that the morphology of the conduction axis is comparable with the human arrangement. As yet, however, to the best of our knowledge, no direct comparison has been made between the species. By comparing our extensive histological findings in the human heart with comparable serially-sectioned datasets prepared from adult murine hearts, we aimed to provide this information.
View Article and Find Full Text PDFArrhythm Electrophysiol Rev
November 2024
In this review, we summarise the ongoing debate surrounding the anatomy of the atrioventricular conduction axis and its relevance to pacing. We highlight previous disagreements and emphasise the importance of understanding the anatomical location of the axis. We give credit and support to the initial descriptions by His and Tawara, in particular their attention to the relationship of the atrioventricular conduction axis with the membranous septum.
View Article and Find Full Text PDFJ Cardiovasc Dev Dis
November 2023
Although first described in the final decade of the 19th century, the axis responsible for atrioventricular conduction has long been the source of multiple controversies. Some of these continue to reverberate. When first described by His, for example, many doubted the existence of the bundle we now name in his honour, while Kent suggested that multiple pathways crossed the atrioventricular junctions in the normal heart.
View Article and Find Full Text PDFA clinical observation usually encountered after vestibuloplasty or interventions aiming at deepening the vestibule with or without simultaneous free epithelialized grafts in the posterior ridges is that they are subjected to major dimensional changes attributed to the buccinator fibers attachment. Hence, this study aimed at assessing the attachment of the buccinator muscles in relation to other anatomical landmarks. An ex-vivo study was performed in cadaver heads to explore the association of fibers attachment in relation to the distance from the crestal aspect of edentulous alveolar process (CAP) and the vestibular depth (VD), crestal band of keratinized mucosa (KM), and ridge height (RH).
View Article and Find Full Text PDFDamage to the atrioventricular conduction axis continues to be a problem subsequent to transcatheter implantation of aortic valvar prostheses. Accurate knowledge of the precise relationships of the conduction axis relative to the aortic root could greatly reduce the risk of such problems. Current diagrams highlighting these relationships rightly focus on the membranous septum.
View Article and Find Full Text PDFBackground: It is almost 100 years ago since Mahaim described the so-called paraspecific connections between the ventricular conduction axis and the crest of the muscular ventricular septum, believing such pathways to be ubiquitous. These pathways, however, have yet to be considered as potential pathways for septal activation during His bundle pacing.
Materials: So as to explore the hypothesis that specialised septal pathways might provide the substrate for septal activation during His bundle pacing, we compared the findings from 22 serially sectioned histological datasets and 34 different individuals undergoing His bundle pacing.
The ventricular components of the conduction axis remain vulnerable following transcatheter aortic valvar replacement. We aimed to describe features which may be used accurately by interventionalists to predict the precise location of the conduction axis, hoping better to avoid conduction disturbances. We scanned eight normal adult heart specimens by 3T magnetic resonance, using the images to simulate histological sections in order accurately to place the conduction axis back within the heart.
View Article and Find Full Text PDFCharacterization of atrial myocardial infarction is hampered by the frequent concurrence of ventricular infarction. Theoretically, atrial infarct scarring could be recognized by multifrequency tissue impedance, like in ventricular infarction, but this remains to be proven. This study aimed at developing a model of atrial infarction to assess the potential of multifrequency impedance to recognize areas of atrial infarct scar.
View Article and Find Full Text PDFIntroduction: Non-steroidal anti-inflammatory drugs and opioids are widely prescribed for the treatment of mild to severe pain. Wide interindividual variability regarding the analgesic efficacy and adverse reactions to these drugs (ADRs) exist although the mechanisms responsible for these ADRs are not well understood.
Areas Covered: We provide an overview of the clinical impact of variants in genes related to the pharmacokinetics and pharmacodynamics of painkillers, as well as those associated with the susceptibility to ADRs.
Herzschrittmacherther Elektrophysiol
June 2022
Exact knowledge of the anatomy of the left atrial appendage (LAA) is crucial for LAA isolation by catheter ablation and for interventional LAA occlusion in patients with atrial fibrillation. This review outlines the current anatomical understanding of LAA morphology from ostium to distal lobes, myocardial fiber orientation and wall structure, and adjacent structures such as the left upper pulmonary vein with the Coumadin ridge, the circumflex artery with its side branches, the aortic root, pulmonary artery, and the pericardial space. Insight into these details will facilitate these interventions and reduce the risk of complications.
View Article and Find Full Text PDFHerzschrittmacherther Elektrophysiol
June 2022
The different forms of atrial flutter (AFL) and atrial macroreentrant tachycardias are strongly related to the atrial anatomy in structurally normal atria, and even more so in patients with dilated chambers or with previous interventions. Atrial anatomy, macro- and microscopic tissue disposition including myocardial fibers, conduction system and connective tissue is complex. This review summarizes knowledge of atrial anatomy for the interventional electrophysiologist to better understand the pathophysiology of and ablation options for these complex arrhythmias, as well as to perform catheter ablation procedures safely and effectively.
View Article and Find Full Text PDFThe pathways for excitation of the atrioventricular node enter either superiorly, as the so-called 'fast' pathway, or inferiorly as the 'slow' pathway. However, knowledge of the specific anatomical details of these pathways is limited. Most of the experimental studies that established the existence of these pathways were conducted in mammalian hearts, which have subtle differences to human hearts.
View Article and Find Full Text PDFDespite years of research, many details of the formation of the atrioventricular conduction axis remain uncertain. In this study, we aimed to clarify the situation. We studied three-dimensional reconstructions of serial histological sections and episcopic datasets of human embryos, supplementing these findings with assessment of material housed at the Human Developmental Biological Resource.
View Article and Find Full Text PDFAims: The arrangement of the conduction axis is markedly different in various mammalian species. Knowledge of such variation may serve to question the validity of using animals as prospective models for design of systems for clinical use.
Methods And Results: We compared the arrangement of the atrioventricular conduction axis in human, murine, canine, porcine, and bovine hearts, examining serially sectioned datasets from 20 human, 16 murine, 3 porcine, 5 canine, and 1 bovine hearts.
Aims: Seeking to account for accessory atrioventricular conduction potentially leading to ventricular pre-excitation, Mahaim in the mid-20th century had described pathways between the atrioventricular conduction axis and the muscular ventricular septum. We aimed to look for such 'paraspecific' connections in adult human hearts.
Methods And Results: We serially sectioned 21 hearts, covering the triangle of Koch and the aortic root, and assessing the atrioventricular node, the penetration of the conduction axis, and the bundle branches in our search for fasciculo-ventricular connections.
Int J Periodontics Restorative Dent
November 2021
This pilot study aimed to assess the diagnostic accuracy of CBCT in identifying peri-implantitis-like bone defects in cadavers. Three cadaver dental arches treated with the Thiel embalming method were used. Three different types of peri-implant bone defects (buccal dehiscence, two- to three-wall defects, and circumferential defects) were prepared on 15 implants.
View Article and Find Full Text PDFArrhythm Electrophysiol Rev
October 2021
Extensive knowledge of the anatomy of the atrioventricular conduction axis, and its branches, is key to the success of permanent physiological pacing, either by capturing the His bundle, the left bundle branch or the adjacent septal regions. The inter-individual variability of the axis plays an important role in underscoring the technical difficulties known to exist in achieving a stable position of the stimulating leads. In this review, the key anatomical features of the location of the axis relative to the triangle of Koch, the aortic root, the inferior pyramidal space and the inferoseptal recess are summarised.
View Article and Find Full Text PDFCross-hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs) is a relatively common, non-allergic, adverse drug event triggered by two or more chemically unrelated NSAIDs. Current evidence point to COX-1 inhibition as one of the main factors in its etiopathogenesis. Evidence also suggests that the risk is dose-dependent.
View Article and Find Full Text PDFConduction problems still occur following transcatheter aortic valvar replacement. With this in mind, we have assessed the relationship of the conduction axis to the aortic root. We used serial histological sections, made perpendicular to the base of the triangle of Koch in nine hearts, and perpendicular to the aortic root in 11 hearts.
View Article and Find Full Text PDFBackground: Subtle differences exist between dog and human, despite use of the dog as a model for cardiac surgical and electrophysiological research.
Objective: The purpose of this study was to investigate the differences in the atrioventricular conduction axis and adjacent structures between dogs and humans.
Methods: We prepared 33 human and 5 canine hearts for serial histologic sections of the atrioventricular conduction axis, making correlations with gross anatomic findings.
Human anatomy is a core subject that students of all health degrees are required to pass. Practical classes with human cadavers are a widely used educational resource in medicine, but are less frequent in other health degrees. Determining how first-year podiatry, nursing, and physiotherapy students cope with human anatomy practical classes and identifying the presence of physical reactions and possible causes of distress they experience in the dissection room are essential steps in designing a guidance plan to address students' needs.
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