Heterogeneous pulmonary vein myocardial cell repolarization implications for reentry and triggered activity

Yasushi Miyauchi, Hideki Hayashi, Mizuho Miyauchi, Yuji Okuyama, William J. Mandel, Peng Sheng Chen, Hrayr S. Karagueuzian

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

Background: Myocardial cells in the pulmonary veins (PVs) are thought to play a major role in the initiation and maintenance of atrial arrhythmias, including atrial fibrillation. However, systematic single-cell microelectrode recordings from different regions in intact PV-atrial tissues are lacking. Objectives: The purpose of this study was to determine the transmembrane action potential properties of myocardial cells in different regions of the PV and the left atrium (LA) and assess their arrhythmogenic potential during perfusion with isoproterenol (ISO) and rapid atrial pacing. Methods: Glass microelectrode recordings of action potentials were made from the left PV and the LA in Langendorff-perfused young (3-4 month) male rats (Fisher344) (n = 9). Results: Action potential duration (APD) of atrial and PV cells had similar duration at a pacing cycle length (CL) of 200 ms. However, shortening of the pacing CL to 100 ms led to heterogeneous repolarization of PV cells. Mid-PV cells had a significantly higher maximum slope of APD restitution than atrial or other PV sites. Intra-PV conduction block developed at rates when LA and proximal PV cells manifested 1:1 capture. Perfusion of ISO and rapid atrial pacing promoted the emergence of early afterdepolarization (EAD) and triggered beats in two out of nine tissues, causing premature atrial activation. No difference in resting potential or AP amplitude could be detected among the PV and LA cells. Conclusions: PV myocardial cells develop marked heterogeneity in repolarization, and there is a slight ease of developing EAD and triggered activity in response to rapid pacing and ISO infusion.

Original languageEnglish (US)
Pages (from-to)1339-1345
Number of pages7
JournalHeart Rhythm
Volume2
Issue number12
DOIs
StatePublished - Dec 1 2005
Externally publishedYes

Keywords

  • Action potential
  • Early afterdepolarization
  • Pulmonary vein
  • Repolarization
  • Triggered activity

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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    Miyauchi, Y., Hayashi, H., Miyauchi, M., Okuyama, Y., Mandel, W. J., Chen, P. S., & Karagueuzian, H. S. (2005). Heterogeneous pulmonary vein myocardial cell repolarization implications for reentry and triggered activity. Heart Rhythm, 2(12), 1339-1345. https://doi.org/10.1016/j.hrthm.2005.09.015