Tag Archives: arrythmias

Introduction Hyperpolarisation-activated and cyclic nucleotide-gated (HCN) cation (Na+/K+) currents are generated by four members of the HCN-channel family – HCN1–4.1 The currents of these channels, often designated as If (funny channel) or Ih (hyperpolarisation-activated cation channels), are activated by membrane hyperpolarisation to produce a graded depolarisation in phase 4 of the cardiac action potential. The most prominent channel in the pacemaker region of the heart, essential to the automaticity of the sinus node, is the HCN4 channel.1 Historically, pathogenic variants in HCN4 have been associated with a sick sinus syndrome phenot

Laboratory testing of digoxin levels Laboratories in the National Health Service (NHS) acute trusts will have arrangements in place for routine therapeutic drug level monitoring of digoxin. Routine assays may not be available on a daily basis. However, local arrangements should exist to ensure the availability of urgent testing in cases of suspected digoxin toxicity 24 hours a day. One commonly used method is the electro-chemiluminescence immunoassay (Roche ECLIA®). This assay involves adding a combination of Ruthenium-labelled digoxin-specific monoclonal antibodies, a digoxin derivative labelled with biotin, and a fluorescent marker attache