Background:There is a gradual progression from paroxysmal to persistent atrial fibrillation (AF) in humans. To elucidate the mechanism involved, the creation of an artificial atrial substrate to persist AF in mice was attempted.

Methods and Results:This study used wild type (WT) mice, but it is difficult to induce AF in them. A novel antegrade perfusion method from the left ventricle (LV) to enlarge both atria for artificial atrial modification was proposed in this study. Short duration AF was induced by burst pacing under this method. Optical mapping analysis revealed non-sustained focal type and meandering spiral reentrants after short duration AF. A tiny artificial substrate (~1.2 mm in diameter) was added in by laser irradiation to create a critical atrial arrhythmogenic substrate. Burst pacing was performed in a non-laser group (n=8), a circular-shape laser group (n=8), and a wedge-shaped dent laser group (n=8). We defined AF and atrial tachycardia (AT) as atrial arrhythmia (AA). Long-lasting AA was defined as lasting for ≥30 min. Long-lasting AA was observed in 0/8, 0/8, and 6/8 (75%) mice in each group. Optical mapping analysis revealed that the mechanism was AT with a stationary rotor around the irradiated margin.

Conclusions:Regrettably, this study failed to reproduce persistent AF, but succeeded in creating an arrhythmic substrate that causes sustained AT in WT mice.

背景：人类的房颤从阵发性逐渐发展为持续性心房颤动 (AF)。为了阐明所涉及的机制，尝试创建人工心房基质以在小鼠中持续存在 AF。

方法和结果：本研究使用野生型 (WT) 小鼠，但很难在其中诱导 AF。本研究提出了一种从左心室 (LV) 扩大双心房以进行人工心房改造的新型顺行灌注方法。在这种方法下，突发起搏可诱发短时 AF。光学映射分析揭示了短时 AF 后非持续的焦点类型和曲折的螺旋折返。通过激光照射添加了一个微小的人造基质（直径约 1.2 毫米），以创建一个临界心房心律失常基质。在非激光组（n=8）、圆形激光组（n=8）和楔形凹痕激光组（n=8）中进行突发起搏。我们将 AF 和房性心动过速 (AT) 定义为房性心律失常 (AA)。持久 AA 定义为持续 ≥30 分钟。在 0/8、0/8、每组 6/8 (75%) 只小鼠。光学测绘分析表明，该机制是 AT 与辐照边缘周围的固定转子。

结论：令人遗憾的是，这项研究未能重现持续性 AF，但成功地创造了导致 WT 小鼠持续 AT 的心律失常底物。