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Heterogeneous expression of potassium currents and pacemaker currents potentially regulates arrhythmogenesis of pulmonary vein cardiomyocytes.
J Cardiovasc Electrophysiol. 2009 Sep; 20(9):1039-45.JC

Abstract

INTRODUCTION

The relationship between the determining factors and beating rates of pulmonary vein (PV) pacemaker cardiomyocytes has not been fully elucidated. The purposes of this study were to compare the electrophysiological characteristics between PV fast and slow pacemaker cardiomyocytes.

METHODS

Whole-cell patch clamp was used to investigate the action potentials, transient outward currents (I(to)), sustained outward potassium currents (I(Ksus)), rapid delayed rectifier potassium currents (I(Kr)), inward rectifier potassium current (I(K1)), pacemaker currents (I(f)), and transient inward currents in isolated rabbit PV single fast (> or =2.5 Hz) and slow (<2.5 Hz) pacemaker cardiomyocytes.

RESULTS

The fast PV pacemaker cardiomyocytes (n = 66) had lesser negative maximum diastolic potential (-53 +/- 1 mV vs -59 +/- 1 mV, P < 0.001) and larger slope of diastolic depolarization (0.31 +/- 0.02 V/sec vs 0.09 +/- 0.01 V/sec, P < 0.001) than slow PV pacemaker cardiomyocytes (n = 65). Moreover, the PV beating rates correlated well with the slope of diastolic depolarization and maximum diastolic potential with a linear regression. As compared to those in slow PV pacemaker cardiomyocytes, the fast PV pacemaker cardiomyocytes had smaller I(to) and I(K1), and larger I(f) but with similar I(Ksus,)I(Kr), and transient inward currents. However, only few fast (2/34) and slow (1/23) PV pacemaker cardiomyocytes contained barium-sensitive hyperpolarization-activated time-dependent current (I(KH))(.)

CONCLUSIONS AND IMPLICATIONS

The fast and slow PV pacemaker had different electrophysiological characteristics. I(to), I(K1), and I(f) may regulate the beating rates of PV pacemaker cardiomyocytes.

Authors+Show Affiliations

Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

19473300

Citation

Chen, Yao-Chang, et al. "Heterogeneous Expression of Potassium Currents and Pacemaker Currents Potentially Regulates Arrhythmogenesis of Pulmonary Vein Cardiomyocytes." Journal of Cardiovascular Electrophysiology, vol. 20, no. 9, 2009, pp. 1039-45.
Chen YC, Pan NH, Cheng CC, et al. Heterogeneous expression of potassium currents and pacemaker currents potentially regulates arrhythmogenesis of pulmonary vein cardiomyocytes. J Cardiovasc Electrophysiol. 2009;20(9):1039-45.
Chen, Y. C., Pan, N. H., Cheng, C. C., Higa, S., Chen, Y. J., & Chen, S. A. (2009). Heterogeneous expression of potassium currents and pacemaker currents potentially regulates arrhythmogenesis of pulmonary vein cardiomyocytes. Journal of Cardiovascular Electrophysiology, 20(9), 1039-45. https://doi.org/10.1111/j.1540-8167.2009.01480.x
Chen YC, et al. Heterogeneous Expression of Potassium Currents and Pacemaker Currents Potentially Regulates Arrhythmogenesis of Pulmonary Vein Cardiomyocytes. J Cardiovasc Electrophysiol. 2009;20(9):1039-45. PubMed PMID: 19473300.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Heterogeneous expression of potassium currents and pacemaker currents potentially regulates arrhythmogenesis of pulmonary vein cardiomyocytes. AU - Chen,Yao-Chang, AU - Pan,Nan-Hung, AU - Cheng,Chen-Chuan, AU - Higa,Satoshi, AU - Chen,Yi-Jen, AU - Chen,Shih-Ann, Y1 - 2009/05/15/ PY - 2009/5/29/entrez PY - 2009/5/29/pubmed PY - 2009/12/16/medline SP - 1039 EP - 45 JF - Journal of cardiovascular electrophysiology JO - J Cardiovasc Electrophysiol VL - 20 IS - 9 N2 - INTRODUCTION: The relationship between the determining factors and beating rates of pulmonary vein (PV) pacemaker cardiomyocytes has not been fully elucidated. The purposes of this study were to compare the electrophysiological characteristics between PV fast and slow pacemaker cardiomyocytes. METHODS: Whole-cell patch clamp was used to investigate the action potentials, transient outward currents (I(to)), sustained outward potassium currents (I(Ksus)), rapid delayed rectifier potassium currents (I(Kr)), inward rectifier potassium current (I(K1)), pacemaker currents (I(f)), and transient inward currents in isolated rabbit PV single fast (> or =2.5 Hz) and slow (<2.5 Hz) pacemaker cardiomyocytes. RESULTS: The fast PV pacemaker cardiomyocytes (n = 66) had lesser negative maximum diastolic potential (-53 +/- 1 mV vs -59 +/- 1 mV, P < 0.001) and larger slope of diastolic depolarization (0.31 +/- 0.02 V/sec vs 0.09 +/- 0.01 V/sec, P < 0.001) than slow PV pacemaker cardiomyocytes (n = 65). Moreover, the PV beating rates correlated well with the slope of diastolic depolarization and maximum diastolic potential with a linear regression. As compared to those in slow PV pacemaker cardiomyocytes, the fast PV pacemaker cardiomyocytes had smaller I(to) and I(K1), and larger I(f) but with similar I(Ksus,)I(Kr), and transient inward currents. However, only few fast (2/34) and slow (1/23) PV pacemaker cardiomyocytes contained barium-sensitive hyperpolarization-activated time-dependent current (I(KH))(.) CONCLUSIONS AND IMPLICATIONS: The fast and slow PV pacemaker had different electrophysiological characteristics. I(to), I(K1), and I(f) may regulate the beating rates of PV pacemaker cardiomyocytes. SN - 1540-8167 UR - https://www.unboundmedicine.com/medline/citation/19473300/Heterogeneous_expression_of_potassium_currents_and_pacemaker_currents_potentially_regulates_arrhythmogenesis_of_pulmonary_vein_cardiomyocytes_ L2 - https://doi.org/10.1111/j.1540-8167.2009.01480.x DB - PRIME DP - Unbound Medicine ER -