BACKGROUND:Atrial fibrillation is the most common cardiac arrhythmia in the world and increases the risk for stroke and morbidity. During atrial fibrillation, the electric activation fronts are no longer coherently propagating through the tissue and, instead, show rotational activity, consistent with spiral wave activation, focal activity, collision, or partial versions of these spatial patterns. An unexplained phenomenon is that although simulations of cardiac models abundantly demonstrate spiral waves, clinical recordings often show only intermittent spiral wave activity.METHODS:In silico data were generated using simulations in which spiral waves were continuously created and annihilated and in simulations in which a spiral wave was intermittently trapped at a heterogeneity. Clinically, spatio-temporal activation maps were constructed using 60 s recordings from a 64 electrode catheter within the atrium of N=34 patients (n=24 persistent atrial fibrillation). The location of clockwise and counterclockwise rotating spiral waves was quantified and all intervals during which these spiral waves were present were determined. For each interval, the angle of rotation as a function of time was computed and used to determine whether the spiral wave returned in step or changed phase at the start of each interval.RESULTS:In both simulations, spiral waves did not come back in phase and were out of step.” In contrast, spiral waves returned in step in the majority (68%; P=0.05) of patients. Thus, the intermittently observed rotational activity in these patients is due to a temporally and spatially conserved spiral wave and not due to ones that are newly created at the onset of each interval.CONCLUSIONS:Intermittency of spiral wave activity represents conserved spiral wave activity of long, but interrupted duration or transient spiral activity, in the majority of patients. This finding could have important ramifications for identifying clinically important forms of atrial fibrillation and in guiding treatment.

中文翻译：

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人类心房颤动期间空间守恒的螺旋波活动

背景：心房颤动是世界上最常见的心律失常，会增加中风和发病的风险。在心房颤动期间，电激活前沿不再在组织中一致传播，而是显示旋转活动，与螺旋波激活、焦点活动、碰撞或这些空间模式的部分版本一致。一个无法解释的现象是，尽管心脏模型的模拟大量展示了螺旋波，但临床记录通常仅显示间歇性螺旋波活动。 方法：使用螺旋波连续产生和消失的模拟以及螺旋波连续产生和消失的模拟来生成计算机数据。波间歇性地陷入异质性。临床上，时空激活图是使用 N=34 名患者（n=24 名持续性心房颤动）心房内 64 个电极导管的 60 秒记录构建的。顺时针和逆时针旋转螺旋波的位置被量化，并确定了这些螺旋波出现的所有时间间隔。对于每个间隔，计算作为时间函数的旋转角度，并用于确定螺旋波是否在每个间隔开始时逐步返回或改变相位。结果：在两次模拟中，螺旋波都没有同相返回并且步调不一致。”相比之下，大多数患者（68%；P =0.05）的螺旋波同步返回。因此，在这些患者中观察到的间歇性旋转活动是由于时间和空间上保守的螺旋波引起的，而不是由于在每个间隔开始时新创建的螺旋波引起的。结论：螺旋波活动的间歇性代表了长螺旋波活动的保守性，但大多数患者的螺旋活动持续时间中断或短暂。这一发现可能对识别临床上重要的心房颤动形式和指导治疗产生重要影响。