Spatio-temporal analysis of intracellularcalcium oscillation in the pulmonary vein myocardium

观察肺静脉心肌电生理特性，分析其致心律失常活性。一些肺静脉心肌细胞，而不是心房心肌细胞，显示持续的自发Ca2+瞬态。肺静脉心肌细胞的形态和肌浆网含量与心房肌细胞相同。肺静脉心肌的静息负膜电位和向内整流钾电流密度均低于心房。这些结果表明，肺静脉心肌细胞中较低密度的复极电流似乎对细胞内Ca2+升高诱导的去极化起许可作用。

We assessed the electrophysiological properties of pulmonary vein myocardium and analyzed its arrhythmogenic activity. Some of the pulmonary vein cardiomyocytes, but not atrial cardiomyocytes, showed sustained spontaneous Ca2+transients. But morphology and the sarcoplasmic reticulum content of pulmonary vein cardiomyocytes were the same as those of atrial myocytes. The pulmonary vein myocardium had a less negative resting membrane potential and lower density of inwardly rectifying potassium current than atrial. These results suggest that the lower density of repolarizing currents in pulmonary vein cardiomyocytes appears to play a permissive role for depolarization induced by elevation of intracellular Ca2+.