摘要
Introduction: Pulmonary veins (PVs) are known to initiate paroxysmal atrial fibrillation. T-type calcium current (ICa-T) has a role in normal and abnormal automaticity of cardiomyocytes. The aim of this study was to evaluate whether ICa-T contributes to PV electrical activity. Methods and Results: By whole-cell clamp techniques in rabbit myocytes, I Ca-T was identified in 12 (39%) of 31 PV cardiomyocytes with pacemaker activity, 2 (9%) of 23 PV cardiomyocytes without pacemaker activity, and 2 (15%) of 13 atrial myocytes (P < 0.05). Maximum ICa-L and ICa-T densities from PV cardiomyocytes with pacemaker activity were 6.87 ± 2.17 pA/pF and 1.38 ± 0.69 pA/pF, respectively. Nickel (40 μM) decreased the spontaneous activity in 5 (36%) of 14 PV cardiomyocytes (3.1 ± 0.6 Hz vs 2.2 ± 0.5 Hz, P < 0.05), reduced the amplitudes of delayed afterdepolarization from 13 ± 1 mV to 7 ± 1 mV (n = 4, P < 0.05) and inhibited transient inward currents from 1.2 ± 0.2 pA/pF to 0.7 ± 0.1 pA/pF (n = 11, P < 0.01). Conclusions: We conclude that ICa-T contributes to PV pacemaker activity and triggered activity, which are of functional importance in PV arrhythmogenesis.
原文 | 英語 |
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頁(從 - 到) | 567-571 |
頁數 | 5 |
期刊 | Journal of Cardiovascular Electrophysiology |
卷 | 15 |
發行號 | 5 |
DOIs | |
出版狀態 | 已發佈 - 5月 2004 |
ASJC Scopus subject areas
- 心臟病學與心血管醫學
- 生理學(醫學)