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Atrial tachycardia remodeling of pulmonary vein cardiomyocytes: comparison with left atrium and potential relation to arrhythmogenesis.
Circulation. 2005 Feb 15; 111(6):728-35.Circ

Abstract

BACKGROUND

The pulmonary veins (PVs) are important in the pathophysiology of atrial fibrillation (AF), as is atrial tachycardia (AT) remodeling. The relative importance of AT remodeling in PVs versus other atrial sites is unknown. The present study assessed AT-induced cellular changes in PVs versus left atrium (LA) and their relationship to arrhythmogenesis.

METHODS AND RESULTS

We studied ionic currents (single-cell patch clamp) and action potentials (APs; coronary-perfused multicellular preparations) in the PVs and LA free wall of dogs after 7-day AT pacing (400 bpm), as well as in nonpaced control dogs. In controls, rapid (I(Kr)) and slow (I(Ks)) delayed-rectifier currents were larger in PVs; transient-outward (I(to)), inward-rectifier (I(K1)), and L-type Ca2+ (I(Ca)) currents and AP duration were smaller. AT remodeling reduced I(Ca) and I(to), left I(Kr) and I(Ks) unchanged, and increased I(K1) in both LA and PV. AT reduced action potential duration in both LA and PV. LA-PV AP differences became smaller in AT than in control dogs. Premature extrastimuli induced atrial tachyarrhythmias at 4.5+/-2.8% (mean+/-SEM) sites in 6 control multicellular preparations compared with 64.2+/-7.3% sites in 9 AT-remodeled preparations (P<0.001). Resection of all PVs failed to alter atrial tachyarrhythmia inducibility in AT-remodeled preparations (67.5+/-13.1%). PV resection did not significantly change tachyarrhythmia duration (mean 3.9 seconds per heart, range 0.7 to 15.7 seconds before resection; mean 7.0 seconds per heart, range 0.9 to 36.0 seconds after resection) or cycle length (120+/-6 ms before resection, 115+/-8 ms after resection).

CONCLUSIONS

AT produces qualitatively similar ionic remodeling in LA and PVs but reduces PV-LA AP differences. PVs are not essential for AT-induced atrial tachyarrhythmia promotion in this model, which may relate to the failure of PV isolation to prevent AF in some patient populations.

Authors+Show Affiliations

Department of Medicine, Montreal Heart Institute and University of Montreal, Montreal, Quebec, Canada.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15699259

Citation

Cha, Tae-Joon, et al. "Atrial Tachycardia Remodeling of Pulmonary Vein Cardiomyocytes: Comparison With Left Atrium and Potential Relation to Arrhythmogenesis." Circulation, vol. 111, no. 6, 2005, pp. 728-35.
Cha TJ, Ehrlich JR, Zhang L, et al. Atrial tachycardia remodeling of pulmonary vein cardiomyocytes: comparison with left atrium and potential relation to arrhythmogenesis. Circulation. 2005;111(6):728-35.
Cha, T. J., Ehrlich, J. R., Zhang, L., Chartier, D., Leung, T. K., & Nattel, S. (2005). Atrial tachycardia remodeling of pulmonary vein cardiomyocytes: comparison with left atrium and potential relation to arrhythmogenesis. Circulation, 111(6), 728-35.
Cha TJ, et al. Atrial Tachycardia Remodeling of Pulmonary Vein Cardiomyocytes: Comparison With Left Atrium and Potential Relation to Arrhythmogenesis. Circulation. 2005 Feb 15;111(6):728-35. PubMed PMID: 15699259.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Atrial tachycardia remodeling of pulmonary vein cardiomyocytes: comparison with left atrium and potential relation to arrhythmogenesis. AU - Cha,Tae-Joon, AU - Ehrlich,Joachim R, AU - Zhang,Liming, AU - Chartier,Denis, AU - Leung,Tack Ki, AU - Nattel,Stanley, Y1 - 2005/02/07/ PY - 2005/2/9/pubmed PY - 2005/8/10/medline PY - 2005/2/9/entrez SP - 728 EP - 35 JF - Circulation JO - Circulation VL - 111 IS - 6 N2 - BACKGROUND: The pulmonary veins (PVs) are important in the pathophysiology of atrial fibrillation (AF), as is atrial tachycardia (AT) remodeling. The relative importance of AT remodeling in PVs versus other atrial sites is unknown. The present study assessed AT-induced cellular changes in PVs versus left atrium (LA) and their relationship to arrhythmogenesis. METHODS AND RESULTS: We studied ionic currents (single-cell patch clamp) and action potentials (APs; coronary-perfused multicellular preparations) in the PVs and LA free wall of dogs after 7-day AT pacing (400 bpm), as well as in nonpaced control dogs. In controls, rapid (I(Kr)) and slow (I(Ks)) delayed-rectifier currents were larger in PVs; transient-outward (I(to)), inward-rectifier (I(K1)), and L-type Ca2+ (I(Ca)) currents and AP duration were smaller. AT remodeling reduced I(Ca) and I(to), left I(Kr) and I(Ks) unchanged, and increased I(K1) in both LA and PV. AT reduced action potential duration in both LA and PV. LA-PV AP differences became smaller in AT than in control dogs. Premature extrastimuli induced atrial tachyarrhythmias at 4.5+/-2.8% (mean+/-SEM) sites in 6 control multicellular preparations compared with 64.2+/-7.3% sites in 9 AT-remodeled preparations (P<0.001). Resection of all PVs failed to alter atrial tachyarrhythmia inducibility in AT-remodeled preparations (67.5+/-13.1%). PV resection did not significantly change tachyarrhythmia duration (mean 3.9 seconds per heart, range 0.7 to 15.7 seconds before resection; mean 7.0 seconds per heart, range 0.9 to 36.0 seconds after resection) or cycle length (120+/-6 ms before resection, 115+/-8 ms after resection). CONCLUSIONS: AT produces qualitatively similar ionic remodeling in LA and PVs but reduces PV-LA AP differences. PVs are not essential for AT-induced atrial tachyarrhythmia promotion in this model, which may relate to the failure of PV isolation to prevent AF in some patient populations. SN - 1524-4539 UR - https://www.unboundmedicine.com/medline/citation/15699259/Atrial_tachycardia_remodeling_of_pulmonary_vein_cardiomyocytes:_comparison_with_left_atrium_and_potential_relation_to_arrhythmogenesis_ DB - PRIME DP - Unbound Medicine ER -