Jeyaratnam J, Umapathy K, Masse S, Nair K, Farid T, Krishnan S, Nanthakumar K
Ryerson University, Toronto, Canada.
Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:231-4. doi: 10.1109/IEMBS.2011.6090043.
Ventricular fibrillation (VF) occurs due to disorganized electrical activity in the ventricles. This leads to rapid uncoordinated contractions of the ventricles and sudden cardiac death if not treated within minutes of its occurrence. The mechanism of VF initiation and maintenance is still elusive, however the mother rotor and multiple wavelet theories attempt to explain the mechanism behind this lethal arrhythmia. In mother rotor theory, VF is believed to be maintained by high frequency periodic sources called rotors that could be tracked using the phase progression along and through the myocardium using spatio-temporal electrical mapping of the heart. There are exiting works including our previous works that have related the formation of these rotors to anatomical and physiological heterogeneities observed in the myocardium. In this study we performed an correlation exercise of the locations of rotors with scar boundary maps and dominant frequency maps and elucidated this relation using human VF data acquired from isolated human hearts. The results suggest that in 14 rotors over 6 human hearts that we studied, all rotors co-localized to boundary zones of scar and low-high dominant frequency locations. The mean variance of the dominant frequency over the spatial location of the rotor was found to be 0.55 with average minimum of 4.15 Hz to a maximum of 5.71 Hz. This results in human VF data strongly suggest that boundary zones of healthy-non-healthy tissues and low-high frequency boundaries form a favorite substrate for rotor formation.
心室颤动（VF）是由于心室电活动紊乱所致。这会导致心室快速不协调收缩，若在其发生后的几分钟内未得到治疗，会引发心源性猝死。然而，VF起始和维持的机制仍不明确，不过母转子和多子波理论试图解释这种致命性心律失常背后的机制。在母转子理论中，VF被认为是由称为转子的高频周期性源维持的，这些转子可以通过沿心肌并穿过心肌的相位进展，利用心脏的时空电标测来追踪。包括我们之前的工作在内，已有研究将这些转子的形成与心肌中观察到的解剖和生理异质性联系起来。在本研究中，我们对转子位置与瘢痕边界图和主导频率图进行了相关性分析，并利用从离体人心脏获取的人体VF数据阐明了这种关系。结果表明，在我们研究的6颗人心脏中的14个转子中，所有转子都共定位在瘢痕边界区域以及主导频率由低到高的位置。转子空间位置上主导频率的平均方差为0.55，平均最小值为4.15Hz，最大值为5.71Hz。这些人体VF数据结果强烈表明，健康与非健康组织的边界区域以及低频到高频的边界形成了有利于转子形成的基质。
