OBJECTIVES: The purpose of this study was to compare the voltage-dependent K(+) currents of human cells of the right and left atria and determine whether electrical remodeling produced by chronic atrial fibrillation (CAF) is chamber-specific. BACKGROUND: Several data point to the existence of interatrial differences in the repolarizing currents. Therefore, it could be possible that CAF-induced electrical remodeling differentially affects voltage-dependent K(+) currents in each atrium. METHODS: Currents were recorded using the whole-cell patch-clamp in myocytes from left (LAA) and right atrial appendages (RAA) obtained from sinus rhythm (SR) and CAF patients. RESULTS: In SR, LAA and RAA myocytes were divided in 3 types, according to their main voltage-dependent repolarizing K(+) current. CAF differentially modified the proportion of these 3 types of cells on each atrium. CAF reduced the Ca(2+)-independent 4-aminopyridine-sensitive component of the transient outward current (I(to1)) more markedly in the LAA than in the RAA. Therefore, an atrial right-to-left I(to1) gradient was created by CAF. In contrast, the ultrarapid component of the delayed rectifier current (I(Kur)) was more markedly reduced in the RAA than in the LAA, thus abolishing the atrial right-to-left I(Kur) gradient observed in SR. Importantly, in both atria, CAF increased the slow component of the delayed rectifier current (I(Ks)). CONCLUSIONS: Our results demonstrated that in SR there are intra-atrial heterogeneities in the repolarizing currents. CAF decreases I(to1) and I(Kur) differentially in each atrium and increases I(Ks) in both atria, an effect that further promotes re-entry. Copyright (c) 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
OBJECTIVES: The purpose of this study was to compare the voltage-dependent K(+) currents of human cells of the right and left atria and determine whether electrical remodeling produced by chronic atrial fibrillation (CAF) is chamber-specific. BACKGROUND: Several data point to the existence of interatrial differences in the repolarizing currents. Therefore, it could be possible that CAF-induced electrical remodeling differentially affects voltage-dependent K(+) currents in each atrium. METHODS: Currents were recorded using the whole-cell patch-clamp in myocytes from left (LAA) and right atrial appendages (RAA) obtained from sinus rhythm (SR) and CAFpatients. RESULTS: In SR, LAA and RAA myocytes were divided in 3 types, according to their main voltage-dependent repolarizing K(+) current. CAF differentially modified the proportion of these 3 types of cells on each atrium. CAF reduced the Ca(2+)-independent 4-aminopyridine-sensitive component of the transient outward current (I(to1)) more markedly in the LAA than in the RAA. Therefore, an atrial right-to-left I(to1) gradient was created by CAF. In contrast, the ultrarapid component of the delayed rectifier current (I(Kur)) was more markedly reduced in the RAA than in the LAA, thus abolishing the atrial right-to-left I(Kur) gradient observed in SR. Importantly, in both atria, CAF increased the slow component of the delayed rectifier current (I(Ks)). CONCLUSIONS: Our results demonstrated that in SR there are intra-atrial heterogeneities in the repolarizing currents. CAF decreases I(to1) and I(Kur) differentially in each atrium and increases I(Ks) in both atria, an effect that further promotes re-entry. Copyright (c) 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Authors: Hugh Calkins; Gerhard Hindricks; Riccardo Cappato; Young-Hoon Kim; Eduardo B Saad; Luis Aguinaga; Joseph G Akar; Vinay Badhwar; Josep Brugada; John Camm; Peng-Sheng Chen; Shih-Ann Chen; Mina K Chung; Jens Cosedis Nielsen; Anne B Curtis; D Wyn Davies; John D Day; André d'Avila; N M S Natasja de Groot; Luigi Di Biase; Mattias Duytschaever; James R Edgerton; Kenneth A Ellenbogen; Patrick T Ellinor; Sabine Ernst; Guilherme Fenelon; Edward P Gerstenfeld; David E Haines; Michel Haissaguerre; Robert H Helm; Elaine Hylek; Warren M Jackman; Jose Jalife; Jonathan M Kalman; Josef Kautzner; Hans Kottkamp; Karl Heinz Kuck; Koichiro Kumagai; Richard Lee; Thorsten Lewalter; Bruce D Lindsay; Laurent Macle; Moussa Mansour; Francis E Marchlinski; Gregory F Michaud; Hiroshi Nakagawa; Andrea Natale; Stanley Nattel; Ken Okumura; Douglas Packer; Evgeny Pokushalov; Matthew R Reynolds; Prashanthan Sanders; Mauricio Scanavacca; Richard Schilling; Claudio Tondo; Hsuan-Ming Tsao; Atul Verma; David J Wilber; Teiichi Yamane Journal: Heart Rhythm Date: 2017-05-12 Impact factor: 6.343
Authors: Raphael P Martins; Kuljeet Kaur; Elliot Hwang; Rafael J Ramirez; B Cicero Willis; David Filgueiras-Rama; Steven R Ennis; Yoshio Takemoto; Daniela Ponce-Balbuena; Manuel Zarzoso; Ryan P O'Connell; Hassan Musa; Guadalupe Guerrero-Serna; Uma Mahesh R Avula; Michael F Swartz; Sandesh Bhushal; Makarand Deo; Sandeep V Pandit; Omer Berenfeld; José Jalife Journal: Circulation Date: 2014-01-24 Impact factor: 29.690