Department of Biomedical Engineering, Washington University, One Brookings Dr, St Louis, MO 63130, USA.
Circ Res. 2010 Feb 5;106(2):255-71. doi: 10.1161/CIRCRESAHA.109.209841.
Historically, milestones in science are usually associated with methodological breakthroughs. Likewise, the advent of electrocardiography, microelectrode recordings and more recently optical mapping have ushered in new periods of significance of advancement in elucidating basic mechanisms in cardiac electrophysiology. As with any novel technique, however, data interpretation is challenging and should be approached with caution, as it cannot be simply extrapolated from previously used methodologies and with experience and time eventually becomes validated. A good example of this is the use of optical mapping in the sinoatrial node (SAN): when microelectrode and optical recordings are obtained from the same site in myocardium, significantly different results may be noted with respect to signal morphology and as a result have to be interpreted by a different set of principles. Given the rapid spread of the use of optical mapping, careful evaluation must be made in terms of methodology with respect to interpretation of data gathered by optical sensors from fluorescent potential-sensitive dyes. Different interpretations of experimental data may lead to different mechanistic conclusions. This review attempts to address the origin and interpretation of the "double component" morphology in the optical action potentials obtained from the SAN region. One view is that these 2 components represent distinctive signals from the SAN and atrial cells and can be fully separated with signal processing. A second view is that the first component preceding the phase 0 activation represents the membrane currents and intracellular calcium transients induced diastolic depolarization from the SAN. Although the consensus from both groups is that ionic mechanisms, namely the joint action of the membrane and calcium automaticity, are important in the SAN function, it is unresolved whether the double-component originates from the recording methodology or represents the underlying physiology. This overview aims to advance a common understanding of the basic principles of optical mapping in complex 3D anatomic structures.
从历史上看，科学的里程碑通常与方法学突破相关联。同样，心电图、微电极记录以及最近的光学映射的出现，为阐明心脏电生理学的基本机制带来了新的重要进展时期。然而，与任何新技术一样，数据解释具有挑战性，应该谨慎对待，因为它不能简单地从以前使用的方法推断出来，并且随着经验和时间的推移最终会得到验证。光学映射在窦房结（SAN）中的应用就是一个很好的例子：当从心肌的同一部位获得微电极和光学记录时，可能会注意到信号形态有很大差异，因此必须通过不同的一套原理进行解释。鉴于光学映射的广泛应用，必须在方法学方面进行仔细评估，以解释光学传感器从荧光电位敏感染料收集的数据。对实验数据的不同解释可能会导致不同的机械学结论。本综述旨在探讨从 SAN 区域获得的光学动作电位中“双成分”形态的起源和解释。一种观点认为，这两个成分代表来自 SAN 和心房细胞的独特信号，可以通过信号处理完全分离。第二种观点认为，在相位 0 激活之前的第一个成分代表来自 SAN 的膜电流和细胞内钙瞬变引起的舒张去极化。尽管两组的共识是离子机制，即膜和钙自动性的共同作用，在 SAN 功能中很重要，但尚未解决双成分是源自记录方法还是代表潜在生理学。本综述旨在促进对复杂 3D 解剖结构中光学映射基本原理的共同理解。
