title: Heart failure enhances arrhythmogenesis in pulmonary veins.
abstract: 1. Heart failure (HF) predisposes to atrial fibrillation (AF) as a result of substrate remodelling. The present study aimed to investigate the impact of HF on the electrical remodelling of the pulmonary veins (PV) and left atrium (LA). 2. The electrical activity was recorded in LA and PV from control rabbits and rabbits with rapid ventricular pacing-induced HF, using a multi-electrode array system and conventional microelectrodes. 3. Compared with the control-PV (n = 21), the HF-PV (n = 13) had a higher incidence and frequency of rapid pacing-induced spontaneous activity (85 vs 29%, P = 0.005; 3.5 ± 0.2 vs 1.7 ± 0.1 Hz, P < 0.001) and high-frequency irregular electrical activity (92 vs 38%, P = 0.01; 23 ± 1 vs 19 ± 1 Hz, P = 0.003), greater depolarized resting membrane potential (-59 ± 1 vs -70 ± 2 mV, P < 0.001), higher incidence of early afterdepolarizations (EAD; 69 vs 6%, P = 0.001) and delayed afterdepolarizations (DAD; 92 vs 25%, P = 0.001), and slower conduction velocity (38 ± 2 vs 63 ± 2 cm/s, P < 0.05). In comparison to the HF-LA, the HF-PV had a higher incidence of spontaneous activity and high-frequency irregular electrical activity (85 vs 39%, P = 0.04; 92 vs 46%, P = 0.03), and higher incidence of EAD and DAD, and those differences were not found between the control-LA and control-PV. The control-PV with high-frequency irregular electrical activity had a higher incidence of DAD and spontaneous activity as compared with those without it. 4. HF contributed to an increased automaticity, triggered activity and conduction disturbance in the PV. The PV possessed more arrhythmogenic properties, which might play an important role in the genesis of AF in HF.
authors.affiliation: Institute of Clinical Medicine and Department of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Shih-Lin
authors.initials: SL
authors.lastname: Chang
authors.forename: Yao-Chang
authors.initials: YC
authors.lastname: Chen
authors.forename: Yung-Hsin
authors.initials: YH
authors.lastname: Yeh
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Lai
authors.forename: Hung-I
authors.initials: HI
authors.lastname: Yeh
authors.forename: Cheng-I
authors.initials: CI
authors.lastname: Lin
authors.forename: Yung-Kuo
authors.initials: YK
authors.lastname: Lin
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.forename: Tsu-Juey
authors.initials: TJ
authors.lastname: Wu
authors.forename: Yi-Kung
authors.initials: YK
authors.lastname: Huang
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
authors.forename: Yi-Jen
authors.initials: YJ
authors.lastname: Chen
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000503:physiopathology*; D022062:Electrophysiologic Techniques, Cardiac / Q000706:statistics & numerical data*; D006325:Heart Atria / Q000503:physiopathology; D006333:Heart Failure / Q000503:physiopathology*; D008564:Membrane Potentials / Q000502:physiology*; D008839:Microelectrodes; D011667:Pulmonary Veins / Q000503:physiopathology*; D011817:Rabbits