Electric field perturbations of spiral waves attached to millimeter-size obstacles
Electric field perturbations of spiral waves attached to millimeter-size obstacles
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DOI：
10.1529/biophysj.107.116244
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发表时间：
2008-02-15
影响因子：
3.4
通讯作者：
Tung, Leslie
中科院分区：
文献类型：
--
作者：
Cysyk, Joshua;Tung, Leslie
折返性螺旋波可固定在心脏中的小解剖障碍物上，并导致单形室性心动过速，其可退化为多形心动过速和室颤。电场诱导的次级源刺激可以直接在障碍物处激发，并且可以提供终止钉扎波或抑制向更复杂的心律失常转变的手段。我们使用新生大鼠心室肌细胞的汇合单层来研究使用低强度电场刺激来扰动螺旋波。在中心形成直径2- 4 mm的孔以钉扎螺旋波。单层细胞用电压敏感染料di-4-ANEPPS染色，并在253个位点作图。螺旋波开始附着到孔（n = 10个单层）。以增加的强度（0.5-5V/cm）递送持续时间为1-s的电场脉冲，直到波从孔分离后终止。在亚分离强度，周期长度增加。电场强度在脉冲的持续时间内持续，并在脉冲终止后恢复到其原始值。机械地，波尖附近的传导速度随着。在障碍物处的去极化区域中的电场强度。总之，电场导致钉扎螺旋波的强度依赖性减慢或脱离。我们的研究结果表明，一种手段来减速心动过速，可能有助于防止波退化。
Reentrant spiral waves can become pinned to small anatomical obstacles in the heart and lead to monomorphic ventricular tachycardia that can degenerate into polymorphic tachycardia and ventricular fibrillation. Electric field-induced secondary source stimulation can excite directly at the obstacle, and may provide a means to terminate the pinned wave or inhibit the transition to more complex arrhythmia. We used confluent monolayers of neonatal rat ventricular myocytes to investigate the use of low intensity electric field stimulation to perturb the spiral wave. A hole 2-4mm in diameter was created in the center to pin the spiral wave. Monolayers were stained with voltage-sensitive dye di-4-ANEPPS and mapped at 253 sites. Spiral waves were initiated that attached to the hole (n = 10 monolayers). Electric field pulses 1-s in duration were delivered with increasing strength (0.5-5V/cm) until the wave terminated after detaching from the hole. At subdetachment intensities, cycle length increased with. eld strength, was sustained for the duration of the pulse, and returned to its original value after termination of the pulse. Mechanistically, conduction velocity near the wave tip decreased with. eld strength in the region of depolarization at the obstacle. In summary, electric fields cause strength-dependent slowing or detachment of pinned spiral waves. Our results suggest a means to decelerate tachycardia that may help to prevent wave degeneration.