2Akiko Suyama Chishaki, Fang-Jie Li, Akira Takeshita, et al.Different features of ventricular arrhythmias and the RR-interval dynamic in atrial fibrillation related to the patients's clinical characteristics: an analysis using RR-interval plotting. Journal of Electrocardiology Vol.37 No.'3 July 2004.207-217.