PMID- 27616994 OWN - NLM STAT- PubMed-not-MEDLINE DCOM- 20160912 LR - 20200929 IS - 1664-042X (Print) IS - 1664-042X (Electronic) IS - 1664-042X (Linking) VI - 7 DP - 2016 TI - Reduced Sodium Current in the Lateral Ventricular Wall Induces Inferolateral J-Waves. PG - 365 LID - 10.3389/fphys.2016.00365 [doi] LID - 365 AB - BACKGROUND: J-waves in inferolateral leads are associated with a higher risk for idiopathic ventricular fibrillation. We aimed to test potential mechanisms (depolarization or repolarization dependent) responsible for inferolateral J-waves. We hypothesized that inferolateral J-waves can be caused by regional delayed activation of myocardium that is activated late during normal conditions. METHODS: Computer simulations were performed to evaluate how J-point elevation is influenced by reducing sodium current conductivity (GNa), increasing transient outward current conductivity (Gto), or cellular uncoupling in three predefined ventricular regions (lateral, anterior, or septal). Two pig hearts were Langendorff-perfused with selective perfusion with a sodium channel blocker of lateral or anterior/septal regions. Volume-conducted pseudo-electrocardiograms (ECG) were recorded to detect the presence of J-waves. Epicardial unipolar electrograms were simultaneously recorded to obtain activation times (AT). RESULTS: Simulation data showed that conduction slowing, caused by reduced sodium current, in lateral, but not in other regions induced inferolateral J-waves. An increase in transient outward potassium current or cellular uncoupling in the lateral zone elicited slight J-point elevations which did not meet J-wave criteria. Additional conduction slowing in the entire heart attenuated J-waves and J-point elevations on the ECG, because of masking by the QRS. Experimental data confirmed that conduction slowing attributed to sodium channel blockade in the left lateral but not in the anterior/septal ventricular region induced inferolateral J-waves. J-waves coincided with the delayed activation. CONCLUSION: Reduced sodium current in the left lateral ventricular myocardium can cause inferolateral J-waves on the ECG. FAU - Meijborg, Veronique M F AU - Meijborg VM AD - Department of Clinical and Experimental Cardiology, Academic Medical CenterAmsterdam, Netherlands; Interuniversity Cardiology Institute of the NetherlandsUtrecht, Netherlands. FAU - Potse, Mark AU - Potse M AD - Electrophysiology and Heart Modeling Institute LIRYC, Universite de BordeauxBordeaux, France; Modelisation et calculs pour l'electrophysiologie cardiaque (Carmen) team, Inria Bordeaux Sud-OuestBordeaux, France; Center for Computational Medicine in Cardiology, Institute of Computational Science, Universita della Svizzera italianaLugano, Switzerland. FAU - Conrath, Chantal E AU - Conrath CE AD - Department of Clinical and Experimental Cardiology, Academic Medical Center Amsterdam, Netherlands. FAU - Belterman, Charly N W AU - Belterman CN AD - Department of Clinical and Experimental Cardiology, Academic Medical CenterAmsterdam, Netherlands; Electrophysiology and Heart Modeling Institute LIRYC, Universite de BordeauxBordeaux, France. FAU - De Bakker, Jacques M T AU - De Bakker JM AD - Department of Clinical and Experimental Cardiology, Academic Medical CenterAmsterdam, Netherlands; Interuniversity Cardiology Institute of the NetherlandsUtrecht, Netherlands; Department of Medical Physiology, University of UtrechtUtrecht, Netherlands. FAU - Coronel, Ruben AU - Coronel R AD - Department of Clinical and Experimental Cardiology, Academic Medical CenterAmsterdam, Netherlands; Electrophysiology and Heart Modeling Institute LIRYC, Universite de BordeauxBordeaux, France. LA - eng PT - Journal Article DEP - 20160826 PL - Switzerland TA - Front Physiol JT - Frontiers in physiology JID - 101549006 PMC - PMC5000556 OTO - NOTNLM OT - J-wave OT - cellular uncoupling OT - conduction OT - depolarization OT - early repolarization OT - sodium current EDAT- 2016/09/13 06:00 MHDA- 2016/09/13 06:01 PMCR- 2016/08/26 CRDT- 2016/09/13 06:00 PHST- 2016/05/11 00:00 [received] PHST- 2016/08/09 00:00 [accepted] PHST- 2016/09/13 06:00 [entrez] PHST- 2016/09/13 06:00 [pubmed] PHST- 2016/09/13 06:01 [medline] PHST- 2016/08/26 00:00 [pmc-release] AID - 10.3389/fphys.2016.00365 [doi] PST - epublish SO - Front Physiol. 2016 Aug 26;7:365. doi: 10.3389/fphys.2016.00365. eCollection 2016.