scholarly journals Effect of xylazine, medetomidine and dexmedetomidine on cardiac conduction in pigs

2018 ◽  
Vol 74 (1) ◽  
pp. 6057-2018
Author(s):  
ALICJA CEPIEL ◽  
AGNIESZKA NOSZCZYK-NOWAK ◽  
ADRIAN JANISZEWSKI ◽  
ROBERT PASŁAWSKI ◽  
URSZULA PASŁAWSKA
Keyword(s):  
Electrophysiological Study ◽  
Companion Animals ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System ◽  
Electrophysiological Activity ◽  
Study Results ◽  
Electrophysiological Studies ◽  
Animal Preparation ◽  
Heart Arrhythmias

The majority of anaesthetics used in studies regarding heart arrhythmias may affect the cardiac conduction system, thus influencing the results. In veterinary medicine, xylazine, medetomidine and dexmedetomidine are commonly used for premedication in laboratory and companion animals. To date, there have been no studies assessing the effect of these substances on the cardiac conduction system. The aim of this study was to assess the effect of xylazine, medetomidine and dexmedetomidine on the parameters of the cardiac conduction system in pigs. The study was carried out on 18 Great White Polish male pigs weighing from 21 to 40 kg. The animals were divided into three equal groups. The animals from the first group received xylazine at a dose of 2 mg/kg i.v.; those from the second group received medetomidine at 40 mcg/kg i.v.; and those from the third group received dexmedetomidine at 10 mcg/kg i.v. The electrophysiological activity of the heart was analysed using an invasive electrophysiological study (EPS). During the EPS, a decrease in the heart rate after substance administration was observed in all animals, but there were no statistically significant differences in the cardiac conduction parameters. A pro-arrhythmic effect of xylazine was observed, but no statistically significant changes in the EPS parameters were noted. Our results indicate that medetomidine and dexmedetomidine may be used as standard premedication drugs in electrophysiological studies in pigs. Their use may facilitate animal preparation procedures without affecting study results..

scholarly journals Rare SCN10A variants associated with cardiac conduction system diseases

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Hayashi ◽  
N Fujino ◽  
H Furusho ◽  
S Usui ◽  
K Sakata ◽  
...  
Keyword(s):  
Rare Variants ◽  
Association Studies ◽  
Electrophysiological Study ◽  
Sinus Node ◽  
Pacemaker Implantation ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System ◽  
Genome Wide Association Studies ◽  
Standards And Guidelines

Abstract Background The genetic bases of cardiac conduction-system disease (CCSD) range from ion channelopathies to mutations in many other genes. Genome-wide association studies have shown common variants in SCN10A influence cardiac conduction. However, it has not yet to be determined whether vulnerability to CCSD is associated with rare coding sequence variation in the SCN10A gene. Purpose We sought to determine the clinical impact of rare variants in SCN10A in patients with CCSD and classified the variants according to the 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines. Methods We performed screening for rare variants (minor allele frequency ≤0.001) in SCN10A in CCSD patients with an onset at a young age under 65 or those who had a family history of pacemaker implantation (PMI) (n=40; 18 female; mean age, 41±18 years). We transiently expressed engineered variants in ND 7/23 cells, and conducted whole-cell voltage clamp experiments to clarify the functional properties of the Nav1.8 current. Results We identified nine rare variants in SCN10A in 7 patients. Two patients were carriers of two rare variants in SCN10A and 5 were carriers of one rare variant in SCN10A. Four patients were affected with sinus node dysfunction, 1 were atrioventricular block, and 2 were both dysfunctions. We performed electrophysiological study for 8 of 9 rare variants. It demonstrated that 2 rare variants showed gain-of-function, and 3 rare variants showed loss-of-function. We finally determined 5 likely pathogenic variants in SCN10A in 5 patients (12.5%) according to the ACMG standards and guidelines. All 5 patients underwent a pacemaker implantation at an average age of 43±16. Conclusions These results demonstrate that SCN10A variants play a pivotal role in enhanced susceptibility of CCSD. We suggest the importance for screening SCN10A variants in clinical settings. Funding Acknowledgement Type of funding source: None

scholarly journals Impact of functional studies on exome sequence variant interpretation in early-onset cardiac conduction system diseases

2020 ◽  
Vol 116 (13) ◽  
pp. 2116-2130 ◽  
Author(s):  
Kenshi Hayashi ◽  
Ryota Teramoto ◽  
Akihiro Nomura ◽  
Yoshihiro Asano ◽  
Manu Beerens ◽  
...  
Keyword(s):  
Rare Variants ◽  
Electrophysiological Study ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System ◽  
Functional Studies ◽  
Pathogenic Variants ◽  
Uncertain Significance ◽  
Standards And Guidelines

Abstract Aims The genetic cause of cardiac conduction system disease (CCSD) has not been fully elucidated. Whole-exome sequencing (WES) can detect various genetic variants; however, the identification of pathogenic variants remains a challenge. We aimed to identify pathogenic or likely pathogenic variants in CCSD patients by using WES and 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines as well as evaluating the usefulness of functional studies for determining them. Methods and results We performed WES of 23 probands diagnosed with early-onset (<65 years) CCSD and analysed 117 genes linked to arrhythmogenic diseases or cardiomyopathies. We focused on rare variants (minor allele frequency < 0.1%) that were absent from population databases. Five probands had protein truncating variants in EMD and LMNA which were classified as ‘pathogenic’ by 2015 ACMG standards and guidelines. To evaluate the functional changes brought about by these variants, we generated a knock-out zebrafish with CRISPR-mediated insertions or deletions of the EMD or LMNA homologs in zebrafish. The mean heart rate and conduction velocities in the CRISPR/Cas9-injected embryos and F2 generation embryos with homozygous deletions were significantly decreased. Twenty-one variants of uncertain significance were identified in 11 probands. Cellular electrophysiological study and in vivo zebrafish cardiac assay showed that two variants in KCNH2 and SCN5A, four variants in SCN10A, and one variant in MYH6 damaged each gene, which resulted in the change of the clinical significance of them from ‘Uncertain significance’ to ‘Likely pathogenic’ in six probands. Conclusion Of 23 CCSD probands, we successfully identified pathogenic or likely pathogenic variants in 11 probands (48%). Functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants in patients with CCSD. SCN10A may be one of the major genes responsible for CCSD.

scholarly journals Sudden Unexpected Death Associated with Arrhythmogenic Cardiomyopathy: Study of the Cardiac Conduction System

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1323
Author(s):  
Giulia Ottaviani ◽  
Graziella Alfonsi ◽  
Simone G. Ramos ◽  
L. Maximilian Buja
Keyword(s):  
Fibromuscular Dysplasia ◽  
Ventricular Myocardium ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Future Research ◽  
Cardiac Conduction System ◽  
Arrhythmogenic Cardiomyopathy ◽  
Unexpected Death ◽  
The Past ◽  
The Right

A retrospective study was conducted on pathologically diagnosed arrhythmogenic cardiomyopathy (ACM) from consecutive cases over the past 34 years (n = 1109). The anatomo-pathological analyses were performed on 23 hearts diagnosed as ACM (2.07%) from a series of 1109 suspected cases, while histopathological data of cardiac conduction system (CCS) were available for 15 out of 23 cases. The CCS was removed in two blocks, containing the following structures: Sino-atrial node (SAN), atrio-ventricular junction (AVJ) including the atrio-ventricular node (AVN), the His bundle (HB), the bifurcation (BIF), the left bundle branch (LBB) and the right bundle branch (RBB). The ACM cases consisted of 20 (86.96%) sudden unexpected cardiac death (SUCD) and 3 (13.04%) native explanted hearts; 16 (69.56%) were males and 7 (30.44%) were females, ranging in age from 5 to 65 (mean age ± SD, 36.13 ± 16.06) years. The following anomalies of the CCS, displayed as percentages of the 15 ACM SUCD cases in which the CCS has been fully analyzed, have been detected: Hypoplasia of SAN (80%) and/or AVJ (86.67%) due to fatty-fibrous involvement, AVJ dispersion and/or septation (46.67%), central fibrous body (CFB) hypoplasia (33.33%), fibromuscular dysplasia of SAN (20%) and/or AVN (26.67%) arteries, hemorrhage and infarct-like lesions of CCS (13.33%), islands of conduction tissue in CFB (13.33%), Mahaim fibers (13.33%), LBB block by fibrosis (13.33%), AVN tongue (13.33%), HB duplicity (6.67%%), CFB cartilaginous meta-hyperplasia (6.67%), and right sided HB (6.67%). Arrhythmias are the hallmark of ACM, not only from the fatty-fibrous disruption of the ventricular myocardium that accounts for reentrant ventricular tachycardia, but also from the fatty-fibrous involvement of CCS itself. Future research should focus on application of these knowledge on CCS anomalies to be added to diagnostic criteria or at least to be useful to detect the patients with higher sudden death risks.

scholarly journals Functional suppression of Kcnq1 leads to early sodium channel remodelling and cardiac conduction system dysmorphogenesis

2013 ◽  
Vol 98 (3) ◽  
pp. 504-514 ◽  
Author(s):  
Angel J. de la Rosa ◽  
Jorge N. Domínguez ◽  
David Sedmera ◽  
Bara Sankova ◽  
Leif Hove-Madsen ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System

Sudden death due to lymphomatous infiltration of the cardiac conduction system

2003 ◽  
Vol 12 (2) ◽  
pp. 77-81 ◽  
Author(s):  
Giulia Ottaviani ◽  
Luigi Matturri ◽  
Lino Rossi ◽  
Dan Jones
Keyword(s):  
Sudden Death ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System
Sign in / Sign up

Export Citation Format

Share Document