This study suggests that in Purkinje fibers, TRPM4 channels may account for sodium background current (I<sub>Nab</sub>), and that a heterogeneous expression of TRPM4 channels in the His/Purkinje system is required for type II heart block, as seen clinically.
Mutations in TRPM4 gene that encodes for transient receptor potential melastatin 4 have recently been reported to cause familial cases of PCCD and heart block.
Transient receptor potential cation channel subfamily melastatin member 4 (TRPM4), a Ca2+-activated nonselective cation channel abundantly expressed in the heart, has been implicated in conduction block and other arrhythmic propensities associated with cardiac remodelling and injury.
Ro60-associated single-stranded RNA links inflammation with fetal cardiac fibrosis via ligation of TLRs: a novel pathway to autoimmune-associated heart block.
In this study, we define the cellular mechanism leading to the disease and show that maternal autoantibodies directed to a specific epitope within the leucine zipper amino acid sequence 200-239 (p200) of the Ro52 protein correlate with prolongation of fetal atrioventricular (AV) time and heart block.
Desmin myopathy is a familial or sporadic disorder characterized by the presence of desmin mutations that cause skeletal muscle weakness associated with cardiac conduction block, arrhythmia and heart failure.
Mutations in NKX2-5 have been found in families showing secundum ASD and atrioventricular (AV) conduction block and in some individuals with tetralogy of Fallot.
Isolated heart block in children, often associated with maternal autoimmune disease leading to anti-Ro/SS-A auto-antibody production, is an infrequent but potentially lethal disorder.
The overproduction of IP-10 by PnMECs leads to the focal breakdown of the BNB and may help to mediate the transfer of pathogenic T cells across the BNB, thereby resulting in the appearance of conduction block in electrophysiological studies of patients with MADSAM and MMN.
Patients with hereditary ATTR amyloidosis occasionally show electrophysiological demyelinating features without conduction block following severe axonal degeneration.
While the true frequency of heart block associated with anti-U1RNP remains to be determined, this study might raise the consideration of echocardiographic surveillance in this setting.
Our findings indicate that a novel heterozygous missense mutation c.G1725T of the CLCA2 gene may be associated with heart block disease and the mutation in this gene may lead to sinus node lesions and conduction blocking.
Our data suggest that anti-contactin-1 IgG3 induces an acute conduction block that is most probably mediated by autoantibody binding and subsequent complement deposition and may account for acute onset of disease in these patients.
<b>Background:</b> Probenecid is a uricosuric agent that in addition to exerting a positive ionotropic effect in the heart, blocks the ATP transporter Pannexin 1 and inhibits the Cl<sup>-</sup>/HCO<sub>3</sub><sup>-</sup> exchanger, pendrin.